TYPE Original Research

PUBLISHED 02 June 2023

DOI 10.3389/fpsyt.2023.1188327

Non-suicidal self-injury function:

OPEN ACCESS prevalence in adolescents with
depression and its associations
EDITED BY
Huanzhong Liu,
Chaohu Hospital of Anhui Medical University,
China

REVIEWED BY
with non-suicidal self-injury
Melanie L. Bozzay,
Brown University, United States
Katarzyna Sitnik-Warchulska,
severity, duration and suicide
Jagiellonian University, Poland

*CORRESPONDENCE Ying Shen 1†, Yingzi Hu 2,3†, Yongjie Zhou 4* and Xiwang Fan 3*
Yongjie Zhou 1
Psychosomatic Medicine, The Third People’s Hospital of Ganzhou, Ganzhou, China, 2 Department of
qingzhu1103@126.com
Psychology, Fudan University, Shanghai, China, 3 Clinical Research Center for Mental Disorders,
Xiwang Fan
Shanghai Pudong New Area Mental Health Center of Tongji University, Shanghai, China, 4 Shenzhen
fanxiwang2020@163.com
Mental Health Center, Shenzhen Kangning Hospital, Shenzhen, China
These authors have contributed equally to this
†

work

RECEIVED 17March 2023

ACCEPTED 15 May 2023 Background: Given that adolescents with depression are at the highest risk for
PUBLISHED 02 June 2023
non-suicidal self-injury (NSSI), a thorough understanding of their NSSI functions,
CITATION
as well as associations between functions and severe behavioral consequences,
Shen Y, Hu Y, Zhou Y and Fan X (2023)
Non-suicidal self-injury function: prevalence in is essential for risk assessment and invention development.
adolescents with depression and its Methods: Adolescents with depression from 16 hospitals across China, for whom
associations with non-suicidal self-injury
severity, duration and suicide. data was available regarding their NSSI function, frequency, number of methods
Front. Psychiatry 14:1188327. used, time characteristics, and suicide history were included. Descriptive statistical
doi: 10.3389/fpsyt.2023.1188327 analyses were performed to determine the prevalence of NSSI functions.
COPYRIGHT Regression analyses were conducted to explore the relationship between NSSI
© 2023 Shen, Hu, Zhou and Fan. This is an
functions and behavioral characteristics of NSSI and suicide attempts.
open-access article distributed under the terms
of the Creative Commons Attribution License Results: Affect regulation was the primary function of NSSI and followed by
(CC BY). The use, distribution or reproduction
anti-dissociation in adolescents with depression. Females recognized automatic
in other forums is permitted, provided the
original author(s) and the copyright owner(s) reinforcement functions more frequently than males, while males had a higher
are credited and that the original publication in prevalence of social positive reinforcement functions. Automatic reinforce
this journal is cited, in accordance with
functions played the prominent role in associations between NSSI functions
accepted academic practice. No use,
distribution or reproduction is permitted which and all the severe behavioral consequences. Specifically, functions of anti-
does not comply with these terms. dissociation, affect regulation, and self-punishment were all associated with NSSI
frequency, while higher levels of endorsements for anti-dissociation and self-
punishment were linked to more NSSI methods, and greater level of endorsement
for anti-dissociation was related to longer NSSI duration. Only the increase in
endorsement of self-punishment was associated with a greater hazard of suicide
attempts.
Conclusion: The dominant functions of NSSI in adolescents with depression
was automatic reinforcement, specifically affect regulation. And prevalence of
NSSI function differed between males and females. Anti-dissociation and self-
punishment seemed to be the most risky factors as they were linked to severe
NSSI or suicide behaviors. More attention should be given to these functions in
risk evaluation, and the targeted interventions should be developed accordingly
in a timely manner.

KEYWORDS

NSSI, self-harm function, adolescents, depression, suicide

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Shen et al. 10.3389/fpsyt.2023.1188327

1. Introduction NSSI in adolescents with depression was reported to reach 42.50% in

China (17), a significant amount considering the country’s massive
Non-suicidal self-injury (NSSI) is the “direct, deliberate population and patients with mental disorders. Therefore, focusing on
destruction of one’s own body tissue in the absence of suicidal intent” adolescents with depression would be a sensible approach to
(1). Adolescents are a vulnerable population for NSSI. Meta-analyses comprehensively understanding NSSI function and providing better
have revealed that the prevalence of NSSI is 17.2% among community medical services for this group.
adolescents (2) and 35%–80% among clinical adolescents (3). NSSI Although NSSI is prevalent, its frequency and methods vary greatly
not only inflicts immediate physical pain and injury but also among individuals (18). Given this high prevalence and diversity of
significantly elevates the risk of suicide attempts (4). Given its high NSSI, it is crucial to focus on the more severe aspects of NSSI for risk
prevalence and damage, NSSI has emerged as a significant public assessment and intervention in clinical practice. The severity of NSSI is
health issue worldwide (5). Nevertheless, avoidance of pain and injury usually measured by frequency and versatility, which refers to the
is an instinct for living beings and is vital for their survival and number of methods used (19). Some studies suggest that automatic
reproduction. The compelling motives behind self-injury that function (or intrapersonal function), rather than social function (or
transcend biological resistance are worth exploring. interpersonal function), is associated with more severe and enduring
NSSI functions refer to the motives or reinforcers of NSSI NSSI (20, 21). However, most of them have not investigated whether the
behavior (6). The four-function model (FFM) proposed by Nock is association differs among specific functions (i.e., affect regulation, self-
often considered the conceptual base of NSSI function, which punishment, and anti-dissociation) within the automatic category. The
classified NSSI functions into four major categories based on the value of such a conclusion is limited for both theoretical research and
source (intrapersonal or interpersonal) and nature (positive or clinical work because automatic reinforcement function (AR) is just a
negative) of reinforcement: automatic negative reinforcement (ANR), broad and ambiguous category of NSSI function. So one aim of this study
automatic positive reinforcement (APR), social negative reinforcement was to explore the relationship between specific AR functions and NSSI
(SNR), and social positive reinforcement (SPR) (7). However, behavioral consequences, which may facilitate the accurate identification
subsequent studies have not consistently supported the FFM and and effective treatment of individuals with severe NSSI, especially under
Klonsky (8) adapted it and proposed a two-factor model, which the circumstance of commonly relative scarcity of medical resource.
divided NSSI functions into intrapersonal function (linked to Although NSSI is not primarily driven by suicidal intentions, it is
automatic reinforcement in the four-function model) and closely associated with suicide. Numerous studies have confirmed the
interpersonal function (linked to social reinforcement in the four- high comorbidity between NSSI and suicide such as (22). However
function model). Further research found that while the source of little is known about the mechanisms underlying this association.
function (i.e., intrapersonal or interpersonal) can always be divided, Most studies have focused on the behavioral characteristics of NSSI
the positive or negative nature of the function, especially ANR and and identified that the frequency and versatility of NSSI are the second
APR in AR, could not always be clearly distinguished (9, 10). However, strongest predictors of suicide attempts, just behind suicidal thoughts
this differentiation was more evident in the social domain (11, 12). (23). This suggests that determining the characteristics of NSSI may
Thus, a three-factor structure has emerged. A similar study (13) based be a promising avenue for estimating latent suicide risk, especially
on Chinese adolescents in a clinical setting supported the three-factor when suicide plans or attempts are private or sudden. Moreover,
model and divided NSSI functions into automatic reinforcement studies have found that NSSI and suicide may partly overlap in
(AR), SNR, and SPR. Therefore, this study also adopted the three- motivation (24), implying that individuals engaging in NSSI under
factor model. AR stems from inner needs, such as affect regulation, certain functions are more likely to simultaneously develop or engage
anti-dissociation, or self-punishment. SNR refers to the effect of NSSI in suicidal behavior. Therefore, it would be worthwhile to explore the
on avoiding interpersonal interactions or social activities. SPR association between NSSI functions and suicide attempts, particularly
considers NSSI as a means of interpersonal communication or in adolescents with depression, who are commonly considered as the
influence, such as attracting attention or seeking understanding. A most vulnerable and main group of NSSI and suicide behaviors (25).
meta-analysis (14) found that intrapersonal functions, with reported This study has three main objectives: first, we aim to describe the
prevalence rates ranging from 66% to 81%, are the most frequently prevalence of NSSI functions in adolescents with depression based on
reported and higher than social functions (from 33%–56%). a large sample. Secondly, we intend to investigate the association
The knowledge of NSSI functions is essential for understanding the between NSSI functions and its frequency, versatility, and duration.
behavior, identifying potential treatment targets, and developing effective Based on previous research, we hypothesize that AR will play a
therapies (15). Despite its significance, NSSI function has received less prominent role. And in the subsequent step, the exploration of which
attention than other characteristics of this behavior. A meta-analysis that specific AR functions are correlative to severe behaviour consequences
examined the prevalence of NSSI functions found that results varied will be conducted. Finally, we aim to investigate the potential
across studies, a potential reason for which was the heterogeneity of association between NSSI functions and co-occurring suicide attempts.
samples (14). It suggested that NSSI function may differ among various
groups. For instance, a research has reported correlations between
borderline personality disorder (BPD) symptoms and NSSI functions 2. Methods
(16), indicating that NSSI functions may differ across various disorders.
Thus, investigating NSSI function in a specific disorder may be necessary, 2.1. Sample and procedure
particularly under the trend of precision medicine. Patients with
depression were found to comprise the largest population of NSSI, and Teenage patients were recruited from 16 hospitals’ psychiatric
adolescents are the most vulnerable people for NSSI. The prevalence of outpatient clinics or inpatient departments in nine provinces of China

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TABLE 1 Demographic and clinical characteristics.

using convenience sampling between December 2020 and December
2021. Inclusion criteria for the study were as follows: (1) adolescents % or M (SD)
between the ages of 12–18 years old; (2) a diagnosis of depressive
Gender
episode made by experienced clinical psychiatrists in accordance with
Male 18.07%
the ICD-10; (3) at least one instance of NSSI behavior in the past year;
and (4) having finished primary education. The exclusion criteria were Female 81.93%
as follows: (1) experiencing acute episode of obvious psychotic Age 14.7 (1.63)
symptoms, and (2) presenting with cognitive or intellectual impairments.
Course of disease
This study was conducted in accordance with the Declaration of
First-episode 44.96%
Helsinki and approved by the Ethics Committee of the Institutional
Review Board (IRB) of Shenzhen Kangning Hospital (020-k021-02). <6 months 21.34%
Written informed consent was obtained from the participants and 6 months–1 year 11.26%
their legal guardians. 1 year-2 years 12.08%
Participants completed the questionnaire independently, with a
≥2 years 9.81%
trained research assistant available to answer any questions they might
have had. To ensure data quality, research assistants would check the Residence
questionnaires after completion, and any unusual answers would Urban 64.12%
be confirmed. Rural 35.88%
A total of 1,101 participants were included, with 199 (18.07%)
Family structure
males and 902 (81.93%) females, and a mean age of 14.7 (SD = 1.63).
Nearly half of the participants (44.96%) had experienced their first Only-child 25.16%
episode of depression. More than half (64.12%) lived in cities. Only Multi-child 74.84%
about a quarter (25.16%) were only-child, whereas 74.84% had
Left-behind experience
siblings. Nearly 20% had experienced being left-behind, which is a
Yes 19.26%
common social phenomenon in China, especially in the
underdeveloped regions. It refers to children who are left behind in No 80.74%
their hometowns while their parents work and earn money in larger Marital status of parents
cities. In this study, participants who had experienced being left-
In marriage 77.38%
behind for over 1 year were classified as left-behind children. Most
Divorced or separated 19.62%
children (77.38%) had parents in marriage, while 19.62% had parents
divorced or separated, and 3% had one or both deceased. In terms of One or both deceased 3.00%
educational status, the majority of adolescents with depression Education status
(79.75%) were enrolled in school, 18.17% were suspended, and 2.09%
At school 79.75%
had dropped out of school. The demographic and clinical information
Suspend school 18.17%
of the participants has been shown in Table 1.
Quit school 2.09%

2.2. Measures
considered” to “greater than 1 week”), and degree of physical pain
2.2.1. Demographics during NSSI (from “no pain” to “severe pain”). The last part measures
In the present study, participants were required to provide their the endorsement of 15 functions using a four-point Likert scale (from
basic personal information in a questionnaire, which included “never” to “often”), which can be categorized into three factors: AR,
demographic characteristics such as gender, age, disease course, place SNR, and SPR. AR includes three main individual functions: affect
of residence, family components, experience of being left behind, regulation (“to stop bad feelings” and “to feel relaxed”), anti-
parents’ marital status, and education status. dissociation (“to relieve feeling numb or empty” and “to feeling
something, even if it was pain”), and self-punishment (“to punish
2.2.2. NSSI characteristics yourself ”). The values of affect regulation and anti-dissociation
NSSI behavior and function characteristics are often assessed by function are the mean of the two items describing them, and the value
the functional assessment of self-mutilation questionnaire (FASM, of self-punishment function is the score of “to punish yourself ” item.
26), which has been demonstrated to possess good psychometric SNR primarily refers to avoiding social activities (e.g., “to avoid doing
properties in both normal populations (27, 28) and clinical samples something unpleasant you do not want”) or interpersonal interactions
(29) across various countries. Qu et al. (13) translated and localized (“to avoid being with people”). SPR focuses on seeking positive
the scale and produced the Chinese version of FASM (C-FASM). In interpersonal feedback (e.g., “to get your parents to understand or
this study, all NSSI variables were measured using the C-FASM, which notice you”). All the three factors demonstrated acceptable internal
consists of three main parts. The first part evaluates 11 self-harm consistency in this sample, AR-α = 0.71, SNR-α = 0.72, and
methods and their frequency in the past year. The second part inquires SPR-α = 0.87. NSSI behavior characteristics, including frequency and
about age of the first NSSI episode, hesitation before action (from “not methods used, should be reported based on the fact in the past year.

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2.2.3. Suicide attempts years. More than half of adolescents with depression (51.50%) engaged
Participants were queried regarding their history of suicidal in the behavior without hesitation, while some (26.61%) hesitated for
thoughts or attempts, and if a suicidal behavior had occurred, the only a few minutes, and the majority (88.28%) did not hesitate for
specific time should be noted. To investigate the co-occurrence of more than 1 h. Regarding the physical pain experienced during NSSI,
NSSI and suicide behaviour, only suicide attempts within the past year more than half (51.23%) reported mild pain, nearly 30% did not feel
were considered to correspond with NSSI. any pain, 17.71% reported moderate pain, and only 2.45% reported
severe pain.

2.3. Data analysis

3.2. Prevalence of NSSI functions
The measurement of NSSI versatility was based on the number of
methods reported by participants, and the sum of NSSI frequency under The most frequently reported functions were “to stop bad feelings”
each method was used to calculate the total NSSI behavior frequency. and “to feel relaxed,” followed by “to relieve feeling numb or empty,”
NSSI duration was defined as the difference between the current and first all of which fell under the AR category. The most commonly reported
NSSI age and there were 64 cases with missing data in the first NSSI age functions of SNR were “to avoid doing something unpleasant you do
were excluded from duration calculation and related data analyses. The not want” and “to avoid being with people.” The function of “to let
scores of the AR, SNR, and SPR subscales were calculated as the mean of others know how desperate you were” and “to get your parents to
their respective items due to differences in the number of items included. understand or notice you” received the highest endorsement in
The skewness of all metric variables (except NSSI frequency) was within SPR. Further elaboration on the prevalence of NSSI functions can
an acceptable range [<2 (30),]. To address non-normality in NSSI be observed in Table 2.
frequency, a natural logarithmic transformation was applied, resulting in Only 15.99% of participants endorsed a single function category,
approximately normal distribution of the transformed frequency data for which was AR (15.44%) in most cases. Furthermore, 29.43% of
use in all relevant analyses. participants endorsed two function categories, including AR + SNR
Descriptive statistics, including percentages, means, and standard (17.08%) and AR + SPR (11.99%). More than half of the participants
deviations, were used to provide a concise report of the basic (54.59%) endorsed all three function categories.
characteristics of NSSI in this sample. The prevalence of NSSI A significant difference was observed in the degree of recognition
functions was determined through the calculation of endorsement of the three function categories (F = 650.73, p = 0.000***, ηp2 = 0.28),
rates for each function. Gender differences were examined using with post hoc analysis indicating that all pairs significantly differed
Mann–Whitney U tests for every single function and t-tests for from each other (p = 0.000***). And the results indicated that the most
function categories. Linear regression was conducted to analyze NSSI commonly endorsed function category of NSSI in adolescents with
frequency. As for the two count variables, negative binomial regression depression was AR, followed by SNR, and then SPR.
was used for NSSI versatility and Poisson regression was for NSSI However, there were some differences between males and females in
duration. It was due to the overdispersion observed in NSSI versatility the prevalence of NSSI functions. Specifically, females endorsed
(but not in NSSI duration), with its variance (6.40) exceeding the AR > SNR > SPR (F = 611.07, p = 0.000***, ηp2 = 0.31; p = 0.000***). Males
mean (4.30) and the dispersion parameter (1.11) was over 1. And endorsed AR > SPR and SNR (F = 59.47, p = 0.000***, ηp2 = 0.17) and no
binary logistic regression was utilized to explore suicide attempts (yes/ significant difference was noted between SPR and SNR (p = 0.54). Females
no). In all regression analyses, the three function categories were first endorsed each function of AR at a higher rate than males, with differences
entered to construct category models. And then, models of the ranging from 1.34% to 12.61%. The mean score of AR category in females
individual AR functions were taken for further examinations. Control was significantly higher than in males, with a moderate effect size. The
variables, including age, gender, and hospital site, were included in all Mann–Whitney U test showed that females had higher endorsement in
regression analyses to eliminate potential confounding effects. All the function of “to punish yourself,” “to feel relaxed,” and “to stop bad
analyses were performed using SPSS version 26.0. Statistical feelings” than males. Males endorsed each function of SPR higher than
significance was set at a two-tailed p < 0.05 (as the default value), and females, especially “to try to get a reaction from someone, even negative,”
Bonferroni correction may be implemented in the event of necessity. for which the rate was 20.01% lower in females, indicating a significant
difference. This was where the greatest gender difference was observed.
Males also gave more endorsement to the function of “to receive more
3. Results attention from your parents or friends” and “to get attention” in SPR than
females, and the score of SPR category was significantly higher in females
3.1. NSSI characteristics than in males. However, no significant difference existed in SPR between
males and females. Age did not correlate with social function and had a
According to the criteria of Muehlenkamp et al. (31), patients significant but weak negative correlation with AR (r = −0.07, p = 0.018*).
were stratified into three groups based on the NSSI frequency they
reported: low-frequency (<5), medium-frequency (5–25), and high-
frequency (≥25), corresponding to proportions of 9.72%, 28.07%, and 3.3. Functions and the severity and
62.22%, respectively. The mean number of methods employed was duration of NSSI
4.30 (SD = 2.53), with the most common being “cut or crave on skin”
(87.83%) and “hit self ” (52.59%). The mean age of onset for NSSI was Age, gender, hospital site, and the three function categories
13.31 (SD = 1.71) years, with an average duration of 1.41 (SD = 1.21) were inputted simultaneously (model 1) to conduct the linear

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Shen et al. 10.3389/fpsyt.2023.1188327

TABLE 2 Prevalence of NSSI functions.

Functions Total Male Female Total M (SD) t or z (p) Cohen’s d

AR 1.76 (0.77) 4.54 (0.000) 0.36

To stop bad feelings 85.38% 78.89% 86.81% 3.66 (0.000) 0.30

To feel relaxed 81.65% 74.37% 83.26% 3.76 (0.000) 0.30

To relieve feeling numb or empty 80.47% 76.88% 81.26% 1.40 (0.162) 0.11

To punish yourself 75.66% 65.33% 77.94% 4.38 (0.000) 0.35

To feel something, even if it was pain 73.66% 70.85% 74.28% 1.89 (0.059) 0.15

SNR 0.79 (0.77) 0.08 (0.938) 0.01

To avoid doing something unpleasant you do

52.41% 54.77% 51.88% 0.76 (0.446) 0.05
not want

To avoid being with people 47.59% 47.24% 47.67% 0.3 (0.764) 0.03

To avoid school, work, or other activities 40.42% 41.71% 40.13% 0.32 (0.750) 0.02

To avoid punishment or paying the

32.97% 34.17% 32.71% 0.09 (0.929) 0.06
consequences

SPR 0.69 (0.77) −3.05 (0.002) 0.24

To let others know how desperate you were 46.41% 52.26% 45.12% −1.87 (0.061) 0.14

To get your parents to understand or notice

40.69% 43.72% 40.02% −1.12 (0.264) 0.09
you

To get help 38.24% 39.20% 38.03% −0.09 (0.927) 0.02

To get attention 37.97% 48.74% 35.59% −3.54 (0.000) 0.26

To try to get a reaction from someone, even

36.88% 53.27% 33.26% −5.38 (0.000) 0.40
negative

To receive more attention from your parents or

35.79% 47.24% 33.26% −3.99 (0.000) 0.30
friends
p after Bonferroni correction = 0.05/18 = 0.0028. Bold = significant after Bonferroni correction.

regression analysis of NSSI frequency. Result revealed that except Through binary logistic regression analysis, only affect regulation
age, only AR was significant after the Bonferroni correction. (AR) was found to be associated with an increased risk of suicide
Although the p-value of SNR was below 0.05, it did not meet the attempts. Specifically, an increase in the endorsement of self-
Bonferroni correction and the beta weight was small. R2 of the punishment was independently relevant to concurrent suicide
model was 0.23, which mean that the model accounted for attempts (refer to Table 4 for detailed results).
approximately 23% variation of NSSI frequency. In Model 2,
which focused on the three specific AR functions, affect
regulation, anti-dissociation, and self-punishment were all 4. Discussion
independently associated with NSSI frequency, see Table 3.
In the negative binomial regression analysis for NSSI versatility, This study sought to investigate the primary functions of NSSI in
another indicator of NSSI severity, AR was also the only significant adolescents with depression, and ascertain the risky functions
function category. And in model 2, only anti-dissociation and self- associated with severe behavioral consequences. The main findings of
punishment survived the Bonferroni correction. the study are as follows: (1) affect regulation was the primary NSSI
The same procedure was conducted for the Poisson regression of function in adolescents with depression, followed by an elevated
NSSI duration, and likewise only AR was significantly associated with function of anti-dissociation observed in this group. And gender
enduring NSSI. However, only anti-dissociation survived in model 2, difference observed in the prevalence of NSSI function was that
while self-punishment did not meet the Bonferroni correction and Females recognized AR more frequently than males, while males had
affect regulation failed to reach statistical significance totally. a higher prevalence of SPR. (2) AR played the prominent role in
associations between NSSI functions and severe behavioral
consequences. And within AR, functions of anti-dissociation, affect
3.4. NSSI functions and suicide attempt regulation, and self-punishment were all positively correlated with
frequency of NSSI. And higher levels of endorsements for anti-
Among adolescents with depression and NSSI, the vast majority dissociation and self-punishment were linked to more NSSI versatility.
(97.09%) reported having suicidal thoughts, and nearly half (49.59%) Only greater levels of endorsement for anti-dissociation were found
reported lifetime suicide attempts. Additionally, over 30% experienced to be linked to longer NSSI duration. (3) AR was also associated with
both NSSI and suicide attempts in the recent 1 year. a higher risk of suicide attempts, and only the increase in

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TABLE 3 Regressions of NSSI functions and the severity and duration. TABLE 4 Regressions of NSSI functions and suicide attempt.

NSSI NSSI NSSI OR p 95% CI 99.375% χ2

frequency versatility duration CI
β (p) OR (p) OR (p) Model 1 25.03

Model 1 Age 0.94 0.116 (0.87, 1.02) (0.84, 1.05)

Age −0.12 (0.000) 0.95 (0.009) 1.18 (0.000) Gender a

0.99 0.958 (0.70, 1.40) (0.61, 1.60)

Gender a
0.01 (0.651) 1.02 (0.810) 1.18(0.046) Hospital cite 0.96 0.014 (0.93, 0.99) (0.92, 1.00)

Hospital cite 0.03 (0.345) 1.01 (0.383) 1.01 (0.144) AR 1.35 0.001 (1.13, 1.63) (1.05, 1.75)

AR 0.43 (0.000) 1.41 (0.000) 1.22 (0.000) SNR 0.90 0.267 (0.74, 1.09) (0.69, 1.17)

SNR 0.07 (0.016) 1.07 (0.187) 1.01 (0.839) SPR 1.19 0.056 (1.00, 1.43) (0.93, 1.53)

SPR −0.03 (0.250) 1.00 (0.928) 1.05 (0.259) Model 2 25.67

Age 0.94 0.125 (0.87, 1.02) (0.84, 1.05)

Model 2
Gendera 1.04 0.819 (0.74, 1.47) (0.65, 1.68)
Age −0.13 (0.000) 0.94 (0.005) 1.18 (0.000)
Hospital cite 0.96 0.021 (0.94, 0.99) (0.92, 1.01)
Gendera 0.00 (0.998) 1.02 (0.799) 1.18 (0.047)
Affect
Hospital cite 0.03 (0.287) 1.01 (0.332) 1.01 (0.145) 1.11 0.273 (0.92, 1.34) (0.86, 1.44)
regulation
Affect
0.18 (0.000) 1.13 (0.012) 1.06 (0.167) Anti-
regulation 1.03 0.661 (0.89, 1.20) (0.84, 1.27)
dissociation
Anti-
0.25 (0.000) 1.15 (0.000) 1.11 (0.003) Self-
dissociation 1.21 0.002 (1.07, 1.36) (1.02, 1.43)
punishment
Self-
0.14 (0.000) 1.13 (0.000) 1.06 (0.031) p after Bonferroni correction = 0.05/8 = 0.00625. Bold = significant after Bonferroni
punishment
correction.
β(p), standardized regression coefficients with p-value. p after Bonferroni a
Female.
correction = 0.05/8 = 0.00625. Bold = significant after Bonferroni correction.
a
Female
Pronounced trait of avoidance was observed in NSSI function.
Consistent with the hypothesis proposed by Nock and Prinstein (7),
self-punishment endorsement was independently related to a greater NSSI functions involve both decrease in negative outcomes and
hazard of suicide attempts. Case-by-case discussions are increase in positive outcomes, which often occur simultaneously and
presented below. intertwine (36, 37). However, our results revealed a greater
endorsement of negative aspects compared to positive ones (e.g., “to
relieve feeling numb or empty” exceeded “to feel something, even if it
4.1. Prevalence of NSSI functions and was pain”). Similar findings have been reported in other studies (28,
gender difference 38). These results suggested that avoiding unwanted internal states
may be more desirable than inducing positive states or that negative
The most prevalent function was affect regulation (“to stop bad reinforcement may be more potent in NSSI, which supports the
feelings” and “to feel relaxed”), which is in line with the prevailing experience avoidance model of NSSI (39). Individuals who engage in
view that NSSI is primarily used to alleviate negative emotions, reduce NSSI may be experiencing severe psychological distress and require
arousal levels, and simultaneously bring about positive feelings, such urgent professional assistance.
as relaxation or calmness (8, 32). The nature of NSSI, as a maladaptive The majority of adolescents with depression in this study had both
emotion regulation strategy, has also been demonstrated in automatic and social functions, and more than half recognized all
adolescents with depression (33). Anti-dissociation (e.g., “to relieve three functional categories, which demonstrates the cross-
feeling numb or empty”) was the second most common function, functionality of NSSI. AR was consistently more prevalent than SNR
which was somewhat at odds with general findings. Meta-analyses (14, and SPR, regardless of gender. However, females endorsed SNR more
34) and a study on BPD adolescents (16) reported that anti- than SPR, while this difference was not observed in males. Males had
dissociation was the relatively less endorsed function. However, our significantly higher SPR scores than females, indicating a greater
sample revealed a higher prevalence of it, which may be attributed to likelihood of self-harm to gain positive social feedback, such as
the association of depression with feelings of numbness and emptiness. attention or response. One theoretical perspective suggests that NSSI
NSSI can provide a person with physical and emotional sensations serves as a powerful form of communication to signal psychological
that facilitate a sense of authenticity and self-awareness, which could distress and avoid abandonment or seek understanding (40, 41). (42)
be the compensation and particularly reinforce the recognition of the conducted a diary study and found that disclosing NSSI behaviors
anti-dissociation function in depression (6). In addition, a study using significantly increased perceived social support. NSSI may be a means
pathway analysis found that the relationship between post-traumatic of influencing the environment, reflecting the adaptability of this
stress, depression, and self-harm is mediated through dissociation, behavior, particularly in males who may experience difficulty
suggesting that anti-dissociation may be the crucial factor in the high expressing their emotions or needs. Additionally, we found that
co-occurrence of NSSI and depression (35). females had significantly higher AR scores than males, who might

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Shen et al. 10.3389/fpsyt.2023.1188327

be more likely to engage in NSSI as a means of self-punishment or it may mitigate the risk of more serious consequences, even if doing
affect regulation. This finding is consistent with previous research (43) so incurs costs.
and may be attributed to the greater prevalence of severe internal
problems among females (44).
4.4. Clinical implications

4.2. Individual automatic functions and the Our findings highlight the significance of conducting a
severity, duration of NSSI comprehensive assessment of NSSI function. A high endorsement of
automatic functions could indicate severe NSSI and underlying
AR was associated with more severe and persistent NSSI in this suicide attempts, which necessitate close monitoring and intensive
study, which is in line with the results of previous studies (42, 46). treatment. In addition, given the multifacetedness NSSI function,
Although affect regulation was the most popular function, it no longer mental health practitioners and clinicians should comprehend the
played the dominant role in the association between NSSI function NSSI functions that patients endorse and devise appropriate treatment
and worse behavioral outcomes. Our study further confirmed that the plans. Currently, the primary therapy for NSSI is dialectical behavioral
three individual automatic functions, anti-dissociation, affect therapy [DBT (51),], which concentrates on affect regulation and
regulation, and self-punishment were associated with NSSI frequency, enhancement of emotion regulation ability and distress tolerance.
and anti-dissociation together with self-punishment were associated However, given our findings that functions of anti-dissociation and
with NSSI versatility. Only anti-dissociation was independently self-punishment might be the more important risky factors,
associated with NSSI duration. Moreover, anti-dissociation beyond we recommend that treatments targeting dissociation and negative
affect regulation showed the strongest overall association, which has self-cognition should be considered, such as behavioral activation
also been partially reflected in Reinhardt’s study (46) that reported (52), mindfulness (53), and cognitive behavioral therapy (CBT),
correlation coefficients between them. And our study further particularly in individuals experiencing depression.
confirmed these relationships through regression analysis.
Our findings partly confirmed and refined the findings of a
preliminary study by Yen et al. (29) that it’s anti-dissociation rather 4.5. Limitations
than affect regulation that was involved in the maintenance of
NSSI. This can be understood in terms of stability. A follow-up study This study has some limitations that should be considered when
(47) found that affect regulation was the most variable function. interpreting the findings. Firstly, the data were cross-sectional, which
Negative emotions easily subside as the internal or external means that only associations between NSSI functions and behavioral
environment improves, at which point there appears to be no reason outcomes were examined, and directionality and causality could not
to continue NSSI. be clarified. Future longitudinal studies should be considered to verify
these findings and explore the predictive role of NSSI functions in
treatment effects or the transition from NSSI to suicide. Secondly,
4.3. Individual automatic functions and participants were only asked to report on NSSI that occurred within
suicide attempt the past year. The lifetime data was unknown, which represents the
overall level and may potentially impacting the results. Thirdly, self-
AR was identified as a significant factor associated with suicide reported data may be subject and exist bias. The use of ecological
attempts, consistent with prior research (42). However, our study momentary assessment techniques could be considered to obtain
revealed that only an increased in the self-punishment function was more objective and impartial behavioral and physiological data.
independently associated with an elevated risk of suicide attempt. Finally, NSSI function is not necessarily equivalent to reinforcement,
Chapman et al. (39) posited that NSSI as a form of self-punishment as sometimes the functions are not effectively satisfied. We suggest
could alleviate negative self-cognition, shame, and self-hatred. And it that future studies could include measures of function validity to gain
has been supported by the findings of experimental studies (48). a deeper understanding of associations between NSSI functions and
However, unlike other functions, self-harm motivated by self- behavioral outcomes from these subtle but essential perspectives.
punishment implicates anger and aggression directed toward oneself.
It can run through the continuum from NSSI to suicidal self-injury
and escalate to the latter (49). That is, when the motivation to punish 4.6. Conclusion
oneself expands to some extent, the most extreme form, suicide, may
be the chosen course of action. In this study, we shed light on the significance of understanding
It is generally believed that intense psychological distress and the functions of NSSI in identifying prevalent motivations and
despair are the primary drivers of suicide (50). Surprisingly, we did potential risk factors associated with severe behaviors. Based on a
not observe a role of affect regulation in the co-occurrence of NSSI large sample, we identified affect regulation as the most prevalent
and suicide. This could be because affect regulation was already function, and found an increase in the endorsement of anti-
effectively achieved through NSSI. As reported by Saraff et al. (21), the dissociation function in adolescents with depression. We also found
majority of participants (94%) recognized the role of NSSI in gender difference that females recognized AR more frequently than
emotional relief. Brausch and Muehlenkamp (47) also found that males, while males had a higher prevalence of SPR. AR was not only
affect regulation was the most effective function in self-reporting. prevalent but also the risky function category linked to severe
These findings demonstrate the value of NSSI as a coping strategy, as outcomes. However, function of affect regulation no longer played the

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Shen et al. 10.3389/fpsyt.2023.1188327

primary role in associations between NSSI function and behavioral administration and funding acquisition. All authors contributed to the
consequences as it did in the prevalence aspect. Instead, anti- article and approved the submitted version.
dissociation and self-punishment seemed to be more risky factors.
Indicators of these functions should be given more attention to risk
evaluation. We recommend that more attention should be given to Funding
these functions in risk evaluation of NSSI, and the targeted
intervention or treatment should be developed accordingly in a This study was supported by the Medical discipline Construction
timely manner. Project of Pudong Health Committee of Shanghai: (Grant No.
PWZzb2022-09), Medical discipline Construction Project of Pudong
Health Committee of Shanghai: (Grant No. PWYgy2021-02), Sanming
Data availability statement Project of Medicine in Shenzhen (No. SZSM202011014), and
Shenzhen Fund for Guangdong Provincial High-level Clinical Key
The raw data supporting the conclusions of this article will Specialties (No. SZGSP013).
be made available by the authors, without undue reservation.

Conflict of interest
Ethics statement
The authors declare that the research was conducted in the
The studies involving human participants were reviewed and absence of any commercial or financial relationships that could
approved by the Ethics Committee of the Institutional Review Board be construed as a potential conflict of interest.
(IRB) of Shenzhen Kangning Hospital (020-k021-02). Written
informed consent to participate in this study was provided by the
participants’ legal guardian/next of kin. Publisher’s note
All claims expressed in this article are solely those of the
Author contributions authors and do not necessarily represent those of their affiliated
organizations, or those of the publisher, the editors and the
YS and YZ: data collection. YS and YH: conceptualization, design reviewers. Any product that may be evaluated in this article, or
and methodology. YH: data analysis and draft writing. YZ and XF: claim that may be made by its manufacturer, is not guaranteed or
supervision, verification and editing. YZ and XF: project endorsed by the publisher.

References
1. Nock MK, Favazza AR. Nonsuicidal self-injury: Definition and classification. In: 12. Dahlstrom O, Zetterqvist M, Lundh LG, Svedin CG. Functions of nonsuicidal
MK Nock editor. Understanding nonsuicidal self-injury: Origins, assessment, and self-injury: exploratory and confirmatory factor analyses in a large community sample
treatment. American Psychological Association. (2009) 9–18. of adolescents. Psychol Assess. (2015) 27:302–13. doi: 10.1037/pas0000034
2. Swannell SV, Martin GE, Page A, Hasking P, St John NJ. Prevalence of nonsuicidal 13. Qu D, Wang Y, Zhang Z, Meng L, Zhu F, Zheng T, et al. Psychometric properties
self-injury in nonclinical samples: systematic review, meta-analysis and meta-regression. of the Chinese version of the functional assessment of self-mutilation (FASM) in
Suicide Life Threat Behav. (2014) 44:273–303. doi: 10.1111/sltb.12070 Chinese clinical adolescents. Front Psych. (2021) 12:755857. doi: 10.3389/
3. Glenn CR, Klonsky ED. Nonsuicidal self-injury disorder: an empirical investigation fpsyt.2021.755857
in adolescent psychiatric patients. J Clin Child Adolesc Psychol. (2013) 42:496–507. doi: 14. Taylor PJ, Jomar K, Dhingra K, Forrester R, Shahmalak U, Dickson JM. A meta-
10.1080/15374416.2013.794699 analysis of the prevalence of different functions of non-suicidal self-injury. J Affect
4. Ribeiro JD, Franklin JC, Fox KR, Bentley KH, Kleiman EM, Chang BP, et al. Self- Disord. (2018) 227:759–69. doi: 10.1016/j.jad.2017.11.073
injurious thoughts and behaviors as risk factors for future suicide ideation, attempts, and 15. Washburn JJ, Richardt SL, Styer DM, Gebhardt M, Juzwin KR, Yourek A, et al.
death: a meta-analysis of longitudinal studies. Psychol Med. (2016) 46:225–36. doi: Psychotherapeutic approaches to non-suicidal self-injury in adolescents. Child Adolesc
10.1017/S0033291715001804 Psychiatry Ment Health. (2012) 6:14. doi: 10.1186/1753-2000-6-14
5. Mumme TA, Mildred H, Knight T. How do people stop non-suicidal self-injury? A 16. Sadeh N, Londahl-Shaller EA, Piatigorsky A, Fordwood S, Stuart BK, McNiel DE,
systematic review. Arch Suicide Res. (2017) 21:470–89. doi: et al. Functions of non-suicidal self-injury in adolescents and young adults with
10.1080/13811118.2016.1222319 borderline personality disorder symptoms. Psychiatry Res. (2014) 216:217–22. doi:
6. Klonsky ED, Muehlenkamp JJ. Self-injury: a research review for the practitioner. J 10.1016/j.psychres.2014.02.018
Clin Psychol. (2007) 63:1045–56. doi: 10.1002/jclp.20412 17. Shao C, Wang X, Ma Q, Zhao Y, Yun X. Analysis of risk factors of non-suicidal
7. Nock MK, Prinstein MJ. A functional approach to the assessment of self-mutilative self-harm behavior in adolescents with depression. Ann Palliat Med. (2021) 10:9607–13.
behavior. J Consult Clin Psychol. (2004) 72:885–90. doi: 10.1037/0022-006X.72.5.885 doi: 10.21037/apm-21-1951
8. Klonsky ED. The functions of self-injury in young adults who cut themselves: 18. Klonsky ED, Olino TM. Identifying clinically distinct subgroups of self-injurers
clarifying the evidence for affect-regulation. Psychiatry Res. (2009) 166:260–8. doi: among young adults: a latent class analysis. J Consult Clin Psychol. (2008) 76:22–7. doi:
10.1016/j.psychres.2008.02.008 10.1037/0022-006X.76.1.22
9. Kaess M, Parzer P, Mattern M, Plener PL, Bifulco A, Resch F, et al. Adverse 19. Ammerman BA, Jacobucci R, Turner BJ, Dixon-Gordon KL, McCloskey MS.
childhood experiences and their impact on frequency, severity, and the individual Quantifying the importance of lifetime frequency versus number of methods in
function of nonsuicidal self-injury in youth. Psychiatry Res. (2013) 206:265–72. doi: conceptualizing nonsuicidal self-injury severity. Psychol Violence. (2020) 10:442–51. doi:
10.1016/j.psychres.2012.10.012 10.1037/vio0000263
10. Leong CH, Wu AM, Poon MM. Measurement of perceived functions of non- 20. Halpin SA, Duffy NM. Predictors of non-suicidal self-injury cessation in adults
suicidal self-injury for Chinese adolescents. Arch Suicide Res. (2014) 18:193–212. doi: who self-injured during adolescence. J Affect Disord Rep. (2020) 1:100017. doi: 10.1016/j.
10.1080/13811118.2013.824828 jadr.2020.100017
11. Bentley KH, Nock MK, Barlow DH. The four-function model of nonsuicidal self- 21. Saraff PD, Trujillo N, Pepper CM. Functions, consequences, and frequency of non-
injury. Clin Psychol Sci. (2014) 2:638–56. doi: 10.1177/2167702613514563 suicidal self-injury. Psychiatry Q. (2015) 86:385–93. doi: 10.1007/s11126-015-9338-6

Frontiers in Psychiatry 08 frontiersin.org

Shen et al. 10.3389/fpsyt.2023.1188327

22. Cheung YT, Wong PW, Lee AM, Lam TH, Fan YS, Yip PS. Non-suicidal self-injury 38. Ong SH, Tan ACY, Liang WZ. Functions of nonsuicidal self-injury in Singapore
and suicidal behavior: prevalence, co-occurrence, and correlates of suicide among adolescents: implications for intervention. Asian J Psychiatr. (2017) 28:47–50. doi:
adolescents in Hong Kong. Soc Psychiatry Psychiatr Epidemiol. (2013) 48:1133–44. doi: 10.1016/j.ajp.2017.03.015
10.1007/s00127-012-0640-4
39. Chapman AL, Gratz KL, Brown MZ. Solving the puzzle of deliberate self-harm:
23. Victor SE, Klonsky ED. Correlates of suicide attempts among self-injurers: a meta- the experiential avoidance model. Behav Res Ther. (2006) 44:371–94. doi: 10.1016/j.
analysis. Clin Psychol Rev. (2014) 34:282–97. doi: 10.1016/j.cpr.2014.03.005 brat.2005.03.005
24. Brown MZ, Comtois KA, Linehan MM. Reasons for suicide attempts and 40. Allen C. Helping with deliberate self-harm: some practical guidelines. Ment
nonsuicidal self-injury in women with borderline personality disorder. J Abnorm Health. (1995) 4:243–50. doi: 10.1080/09638239550037523
Psychol. (2002) 111:198–202. doi: 10.1037//0021-843x.111.1.198
41. Nock MK, Wedig MM, Holmberg EB, Hooley JM. The emotion reactivity scale:
25. Ougrin D, Latif S. Specific psychological treatment versus treatment as usual development, evaluation, and relation to self-injurious thoughts and behaviors. Behav
in adolescents with self-harm. Crisis. (2011) 32:74–80. doi: 10.1027/0227-5910/ Ther. (2008) 39:107–16. doi: 10.1016/j.beth.2007.05.005
a000060
42. Turner BJ, Cobb RJ, Gratz K, Chapman AL. The role of interpersonal conflict and
26. Lloyd-Richardson EE, Perrine N, Dierker L, Kelley ML. Characteristics and perceived social support in nonsuicidal self-injury in daily life. J Abnorm Psychol. (2016)
functions of non-suicidal self-injury in a community sample of adolescents. Psychol 125:288–98.
Med. (2007) 37:1183–92. doi: 10.1017/S003329170700027X
43. Victor SE, Muehlenkamp JJ, Hayes NA, Lengel GJ, Styer DM, Washburn JJ.
27. Reinhardt M, Kökönyei G, Rice KG, Drubina B, Urbán R. Functions of nonsuicidal Characterizing gender differences in nonsuicidal self-injury: evidence from a large
self-injury in a Hungarian community adolescent sample: a psychometric investigation. clinical sample of adolescents and adults. Compr Psychiatry. (2018) 82:53–60. doi:
BMC Psychiatry. (2021) 21:618. doi: 10.1186/s12888-021-03613-4 10.1016/j.comppsych.2018.01.009
28. Thai TT, Jones MK, Nguyen TP, Pham TV, Bui HHT, Kim LX, et al. The prevalence, 44. Crick NR, Zahn-Waxler C. The development of psychopathology in females and
correlates and functions of non-suicidal self-injury in Vietnamese adolescents. Psychol males: current progress and future challenges. Dev Psychopathol. (2003) 15:719–42. doi:
Res Behav Manag. (2021) 14:1915–27. doi: 10.2147/PRBM.S339168 10.1017.S095457940300035X
29. Yen S, Kuehn K, Melvin C, Lauren M, Weinstock LM, Andover MS, et al. 45. Gardner KJ, Paul E, Selby EA, Klonsky ED, Mars B. Intrapersonal and interpersonal
Predicting persistence of nonsuicidal self-injury in suicidal adolescents. Suicide Life functions as pathways to future self-harm repetition and suicide attempts. Front Psychol.
Threat Behav. (2016) 46:13–22. doi: 10.1111/sltb.12167 (2021) 12:688472. doi: 10.3389/fpsyg.2021.688472
30. Tabachnick BG, Fidell LS. Using multivariate statistics. 5th ed. Boston: Allyn & 46. Reinhardt M, Rice KG, Horváth Z. Non-suicidal self-injury motivations in the
Bacon/Pearson Education (2001). light of self-harm severity indicators and psychopathology in a clinical adolescent
31. Muehlenkamp JJ, Brausch AM, Washburn JJ. How much is enough? Examining sample. Front Psychiatry. (2022) 13:1046576. doi: 10.3389/fpsyt.2022.1046576
frequency criteria for NSSI disorder in adolescent inpatients. J Consult Clin Psychol. 47. Brausch AM, Muehlenkamp JJ. Perceived effectiveness of NSSI in achieving
(2017) 85:611–9. doi: 10.1037/ccp0000209 functions on severity and suicide risk. Psychiatry Res. (2018) 265:144–50. doi: 10.1016/j.
32. Wolff JC, Thompson E, Thomas SA, Nesi J, Bettis AH, Ransford B, et al. Emotion psychres.2018.04.038
dysregulation and non-suicidal self-injury: a systematic review and meta-analysis. Eur 48. Schoenleber M, Berenbaum H, Motl R. Shame-related functions of and
Psychiatry. (2019) 59:25–36. doi: 10.1016/j.eurpsy.2019.03.004 motivations for self-injurious behavior. Personal Disord Theory Res Treat. (2014)
33. Gratz KL. Risk factors for and functions of deliberate self-harm: an empirical 5:204–11. doi: 10.1037/per0000035
and conceptual review. Clin Psychol Sci Pract. (2003) 10:192–205. doi: 10.1093/ 49. Oppenheimer CW, Glenn CR, Miller AB. Future directions in suicide and self-
clipsy.bpg022 injury revisited: integrating a developmental psychopathology perspective. J Clin Child
34. Edmondson AJ, Brennan CA, House AO. Non-suicidal reasons for self-harm: a Adolesc Psychol. (2022) 51:242–60. doi: 10.1080/15374416.2022.2051526
systematic review of self-reported accounts. J Affect Disord. (2016) 191:109–17. doi: 50. May AM, Pachkowski MC, Klonsky ED. Motivations for suicide: converging
10.1016/j.jad.2015.11.043 evidence from clinical and community samples. J Psychiatr Res. (2020) 123:171–7. doi:
35. Briere J, Eadie EM. Compensatory self-injury: posttraumatic stress, depression, 10.1016/j.jpsychires.2020.02.010
and the role of dissociation. Psychol Trauma Theory Res Pract Policy. (2016) 8:618–25. 51. Linehan M. Cognitive-behavioral treatment of borderline personality disorder. New
doi: 10.1037/tra0000139 York: Guilford Press (1993).
36. Franklin JC, Puzia ME, Lee KM, Lee GE, Hanna EK, Spring VL, et al. The nature 52. Huguet A, Rao S, McGrath PJ, Wozney L, Wheaton M, Conrod J, et al. A systematic
of pain offset relief in nonsuicidal self-injury. Clin Psychol Sci. (2013) 1:110–9. doi: review of cognitive behavioral therapy and behavioral activation apps for depression.
10.1177/2167702612474440 PLoS One. (2016) 11:e0154248. doi: 10.1371/journal.pone.0154248
37. Selby EA, Nock MK, Kranzler A. How does self-injury feel? Examining automatic 53. Zerubavel N, Messman-Moore TL. Staying present: incorporating mindfulness
positive reinforcement in adolescent self-injurers with experience sampling. Psychiatry into therapy for dissociation. Mindfulness. (2013) 6:303–14. doi: 10.1007/
Res. (2014) 215:417–23. doi: 10.1016/j.psychres.2013.12.005 s12671-013-0261-3

Frontiers in Psychiatry 09 frontiersin.org