INTERNALISING & EXTERNALISING BEHAVIOURS

Strengths and Difficulties

Questionnaire (SDQ)
25-item parent/educator report version for 4–17-year-olds

The Strengths and Difficulties Questionnaire (SDQ) is a 25-item measure designed to assess
behaviours, emotions and relationships over the last six months in children and young people
aged 4–17 years. This original version of the measure is designed for parents or educators
to complete, and includes five subscales aimed at assessing conduct problems, emotional
symptoms, hyperactivity, peer problems and prosocial behaviour.

Test-retest Sensitivity to
Internal consistency reliability Validity change

✓ ✓ ✓ ✓ ✓
Psychometric features (Scale) (Subscale)

Brevity Availability Ease of Scoring Used in the UK

Implementation
features ✓ ✓ ✓ ✓

*Please note that our assessment of this measure is based solely on the English version of the SDQ for parents or teachers of
4–17-year-olds. The other versions of this measure were not assessed and therefore it should not be assumed that they would
receive the same rating.

What is this document?

This assessment of the Strengths and Difficulties Questionnaire (SDQ) has been produced by the Early
Intervention Foundation (EIF) as part of guidance on selecting measures relating to parental conflict and its
impact on children. To read the full guidance report and download assessments of other measures, visit:
https://www.eif.org.uk/resource/measuring-parental-conflict-and-its-impact-on-child-outcomes

• The SDQ is comprised of five subscales, but the internal consistency results for the peer relationship
subscale has been found weaker when compared to that of the combined subscales. Consequently, we
recommend using the Internalising, Externalising and Total Difficulties scores rather than the individual
subscales. For more information, see the ‘subscales’ section below.

• The developers suggest that the standard SDQ, which asks parents or educators to reflect on a child’s
behaviour in the last six months, should not be used more often than every six months, or there will be
overlapping reference periods. To evaluate an intervention shorter than six months, it is therefore best to start
with the standard version of the SDQ, and then use a follow-up version, which asks parents to reflect on their
child’s behavior in the last month. The follow-up version is available at: https://www.sdqinfo.org/py/sdqinfo/
b3.py?language=Englishqz(UK)

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About the measure

Author(s)/ Publication year Type of measure

developer(s) for the original
version of the
measure
Parent or educator
Goodman, R. 1997 report of child.

Versions available There are four other versions of this measure available,
including: a version for parents or educators of 2–4-year-olds,
a self-rated version for 11–17-year-olds, another self-rated
version for youth aged 18 and over, and an informant report
version for youth of that same age. For each of these versions
there is also an equivalent follow-up version. For more
information, please visit https://www.sdqinfo.org.

Outcome(s) This measure has been designed to assess behaviours,

assessed emotions and relationships in children and young people. The
measure provides both an Internalising and an Externalising
score.

Subscales There are five subscales: conduct problems, emotional

symptoms, hyperactivity, peer problems and prosocial
behaviour.
According to the developers, a Total Difficulties score can be
generated by summing the scores of all scales except the
prosocial scale. The developers also propose summing the
scores from the conduct and hyperactivity scales to obtain an
Externalising score, and adding the scores of the emotional
and peer problems scales to produce an Internalising score.
When using a version of the SDQ that includes the ‘impact
supplement’, the items on overall distress and impairment
can be summed to generate an Impact (or Impairment) Score.

Purpose/primary use This measure was originally designed to represent strengths

and difficulties in children and young people.

Mode of This measure can be completed in person or online.

administration

Example item ‘Considerate of other people's feelings.’

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Target population This measure was originally developed for children aged
4–16 years.
However, in June 2014, the developers changed the age range
of the standard SDQ from 4–16 to 4–17 years.

Response format 3-point Likert scale (0 = ‘Not True’, 1 = ‘Somewhat True’,

2 = ‘Certainly True’).

Strengths & Strengths:

limitations
• The SDQ is a valid and reliable measure which is sensitive
to change in short interventions.
• The SDQ assesses both externalising and internalising
problems.
• The SDQ is a short (25-item) measure, which is free to
access and easy to score (the SDQ is available at:
https://www.sdqinfo.org, with a bespoke scoring website
at: https://sdqscore.org/).

Link https://www.sdqinfo.org

Contact details youthinmind@gmail.com

Copyright Please note that the SDQ, whether in English or in another

language, is a copyrighted document that is not in the public
domain. As such, the SDQ may not be modified in any way
(for example, by changing the wording of questions, adding
questions, or administering only subsets of questions). This
is to ensure that the SDQ is fully comparable across studies
and settings. Similarly, to ensure high quality and consistency,
unauthorised translations are not permitted. Paper versions
may be downloaded from the website and subsequently
photocopied without charge by individuals or non-profit
organisations, provided they are not charging families.
Users are not permitted to create or distribute electronic
versions for any purpose without prior authorisation from
Youth In Mind. If you are interested in making translations
or creating electronic versions, you must first contact
youthinmind@gmail.com.

Key reference(s) Goodman, R. (1997). The Strengths and Difficulties

Questionnaire: A research note. Journal of Child
Psychology and Psychiatry, 38(5), 581–586. https://doi.
org/10.1111/j.1469-7610.1997.tb01545.x

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Psychometric features in detail

Internal
consistency

We found a number of papers (Deighton et al., 2014; Haywood et al.,

2014) reporting good internal consistency for the SDQ, with Cronbach’s
✓ alpha values ranging from 0.63 to 0.85.
(Scale)
Deighton et al. (2014) evaluated the parent/carer version of the SDQ
for 4–17-year-olds. The authors reported that internal consistency
coefficients were between 0.63-0.85. This review was based on three
studies conducted by the developers: (i) one with a sample of 403
children aged 4–16 years (Goodman, 1997), (ii) another with two
samples of 11–16-year-olds (one sample comprised of 83 young people
in the community and the other of 116 young people attending a mental
health clinic) (Goodman, Meltzer, & Bailey, 1998), and a (iii) final study
with a sample of 132 children aged 4–7 years (Goodman & Scott, 1999).
Haywood et al. (2014) reported that the SDQ has evidence of internal
consistency (with alpha coefficients ranging from 0.79 to 0.80),
supporting application with groups of children. The review was based
on two studies assessing the measure. One study was conducted with
a sample of 63 11–18-year-old participants. We do not have information
concerning the second study.

Hessel, He, & Dworkin (2017) reported that the Internalising Score had an
alpha coefficient of 0.82, the Externalising Score had an alpha coefficient
✓ of 0.83, and the prosocial behaviour subscale had an alpha coefficient of
(Sub-scales) 0.76. This study was conducted in the US with a sample of 158 fathers
(mean age = 43.47 years, SD = 7.65) of high school and college students.
Palmieri & Smith (2007) reported that internal consistency was above
0.60 for all the five SDQ subscales (alpha coefficients ranged from
0.62 to 0.82) The authors reported that Cronbach’s alpha was 0.88, for
the Total Difficulties score. This study was conducted in the US with a
sample of 733 grandmothers (mean age = 56.1 years, SD = 8.1) providing
full-time care to a grandchild in the absence of that grandchild’s parents
for at least three months.
He et al. (2013) reported good internal consistency coefficients for all
subscales (alpha coefficients ranging from 0.72 to 0.76), except for
the peer relationship scale (alpha coefficient = 0.58). This study was
conducted in the US with a sample of 6,483 adolescent-parent pairs
(children mean age = 15.9 years (SD 0.1), education levels of parents:
12.3 % less than high school graduation, 29.3% high school graduation,
21.3% some college and 37% college graduation or graduate school).
Mark & Pike (2017) reported that all SDQ subscales had alpha
coefficients ranging from 0.74 to 0.80. This study was conducted with
a sample of 78 mothers (mean age = 41.01 years (SD 4.92), mean ages
of the older siblings and younger siblings were 12.05 years (SD ¼ 1.04)
and 9.82 years (SD ¼ 0.89), respectively). The participants were almost
exclusively White British (95%).

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Test-retest According to Achenbach et al. (2008), Goodman (1999) reported an
reliability intraclass correlation of 0.85 for Total Difficulties score but did not
report results for the subscales. The authors did not report the time
span between test and retest.
Achenbach et al. (2008) also reported that in Mellor (2004), a
✓
sample of Australian children was included in a test-retest analysis if
they had completed a second administration of the SDQ two weeks
and four to six months after the first administration. The authors
reported an ICC value of 0.81 for the whole scale after two weeks,
and a value of 0.72 after four to six months.

Validity From our review, we found a number of papers (Achenbach et al.,

2008; Deighton et al., 2014; Stone et al., 2010; Tsang et al., 2012)
reporting good validity for the SDQ subscales. The authors reported
Pearson coefficients ranging from 0.59 and 0.87 with the subscales
✓ of CBCL, a 113-item parent report measure designed to assess
behavioural and emotional problems in children and young people
aged 6–18 years.
In their systematic review, Deighton et al. (2014) evaluated this
measure against CBCL and reported that the Pearson coefficients
between the SDQ and the CBCL were good, between 0.59 and 0.87.
Achenbach et al. (2008) reported that Goodman & Scott (1999) used
a sample of 132 children aged 4–7 years attending dental clinics or
psychiatric clinics in London to study the correlation between the
mothers’ ratings on the SDQ subscales and on the CBCL scales.
Goodman & Scott (1999) reported Pearson correlation coefficients
between 0.59 and 0.84 (the mean was 0.72).
There is also some evidence to suggest that the SDQ correlates
well with clinicians’ reports. Mathai, Anderson, & Bourne (2003)
reported that the Hyperactivity subscale showed a good correlation
with the clinicians’ diagnoses (τ = 0.433, p < 0.001), while the
Conduct problems and Emotional disorders subscales showed
moderate correlations (τ = 0.304, p < 0.001 and τ = 0.258, p < 0.002
respectively). The study was conducted in Australia with a sample of
130 parents of children aged 4–15 years.
Terrelonge & Fugard (2017) reported the all SDQ subscales showed
moderate correlations with CGAS, a clinician-rated scale of general
functioning (r = -0.25 to -0.14 at Time 1 and r = -0.45 to -0.29 at
Time 2). Correlations between CGAS and the pro-social behaviour
subscale (a positively rated item) were r = 0.20 at Time 1 and
r = 0.34 at Time 2.

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Sensitivity to There is evidence that the SDQ can detect changes after
change participation in short parenting and co-parenting interventions.
Keating et al. (2015) reported that the SDQ detected changes from
pre-test to follow-up (SQD total difficulties: F = 8.24, p < 0.01). This
study was a cluster RCT conducted in Ireland, on the Parents Plus
✓ Parenting when Separated programme (a six-week course), aimed
at reducing child emotional and behaviour problems. This study was
conducted with a sample of 161 separated parents and children
(71% female, 79% single and 71.4% had custody of their children,
mean age of children = 9.43 years).
Nitsch et al. (2015) reported that the SDQ detected changes from
pre-test to follow-up (SDQ total difficulties: F = 64.07, p < 0.001. SDQ
Conduct Scale: F = 19.98, p < 0.001. SDQ Emotional Scale: F = 62.76,
p < 0.001. SDQ Peer Scale: F = 11.51 p < 0.001. SQD Prosocial Scale:
F = 9.19, p < 0.001). This study was an RCT conducted in Ireland on
the Parents Plus Adolescent Programme (a six-month programme)
aimed at reducing adolescent behaviour problems. This study was
conducted with a sample of 126 parents with children between the
ages of 10–16 (61% female, mean age of children = 12.34 years).
The developers suggested that the standard SDQ (which asks
parents to reflect on their child’s behaviour in the last six months)
should not be used more often than every six months, or there will be
overlapping reference periods. To evaluate an intervention, it is best
to start with the standard version of the SDQ, and then use a follow-
up version, which asks parents to reflect on their child’s behaviour
in the last month. The follow-up version is available at: https://www.
sdqinfo.org/py/sdqinfo/b3.py?language=Englishqz(UK).

Implementation features in detail

Brevity This measure has 25 items.

Availability This measure is free to use and does not require a clinical license.
Further details can be found at: https://www.sdqinfo.org/py/
sdqinfo/b0.py.

CHILD OUTCOMES MEASURE: SDQ 6 EARLY INTERVENTION FOUNDATION | MARCH 2020

Ease of The SDQ has simple scoring instructions involving basic
scoring calculations. It does not need to be scored by someone with
specific training or qualifications. Scoring can be done by hand or
using the scoring website: https://sdqscore.org/.
It is usually easiest to score all five scales first before working
✓
out the Total Difficulties score. The overall (five-subscale) SDQ
score ranges from 0 to 50, with a higher score indicating
abnormal behaviours. The Total Difficulties score ranges from 0
to 40. The externalising score ranges from 0 to 20 and is the sum
of the conduct and hyperactivity scales. The internalising score
ranges from 0 to 20 and is the sum of the emotional and peer
problems scales.
UK cut-offs are available at http://www.sdqinfo.org/g0.html.

Used in the The SDQ is a commonly used measure which has been cited in
UK several UK studies, including in the assessment of the Incredible
Years Pre-School parenting programme, the Secondary Social and
Emotional Aspects of Learning (SEAL) programme, Triple-P, the
Systemic Transition in Education Programme for Autism Spectrum
✓ Disorder (STEP-ASD), and the Parenting Early Intervention
Programme (Cullen et al., 2013; Edwards et al., 2016; Humphrey et
al., 2010; Little et al., 2012; Mandy et al., 2012). In our review of the
evidence we also found several UK longitudinal studies using SDQ.

Language(s) The SDQ is available in English. The measure has also been
officially translated by the developers into more than 50 languages,
with the complete list available here: https://sdqinfo.org/py/
sdqinfo/b0.py.

References
Achenbach, T.M., Becker, A., Dopfner, M., Heiervang, E., Roessner, V., Steinhausen H. C., & Rothenberger A. (2008).
Multicultural assessment of child and adolescent psychopathology with ASEBA and SDQ instruments: Research
findings, applications, and future directions. Journal of Child Psychology and Psychiatry, 49(3).
Childs, J., Deighton, J., & Wolpert, M. (2013). Defining and measuring mental health and wellbeing: A response
mode report requested by the Department of Health for the Policy Research Unit in the Health of Children, Young
People and Families. Retrieved from http://www.ucl.ac.uk/ebpu/docs/publication_files/Defining_and_measuring_
mental_health_and_wellbeing_in_children-CPRU_RM_report.pdf
Cullen, S.M., Cullen, M.-A., Lindsay, G., & Strand S. (2013). The Parenting Early Intervention Programme in England,
2006–2011: A classed experience? British Educational Research Journal, 39(6), 1025–1043.
Deighton, J., Croudace, T., Fonagy, P., Brown, J., Patalay P., & Wolpert, M. (2014). Measuring mental health and
wellbeing outcomes for children and adolescents to inform practice and policy: A review of child self-report
measures. Child and Adolescent Psychiatry and Mental Health, 8.
Edwards, R.T., Jones, C., Berry, V., Charles, J., Linck, P., Bywater, T., & Hutchings, J. (2016). Incredible Years
parenting programme: Cost-effectiveness and implementation. Journal of Children’s Services, 11(1), 54–72.
Goodman, R. (1997). The Strengths and Difficulties Questionnaire: A research note. Journal of Child Psychology
and Psychiatry, 38, 581–586.
Haywood, K., Collin, S., & Crawley, E. (2014). Assessing severity of illness and outcomes of treatment in children
with chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME): A systematic review of patient-reported
outcome measures (PROMs). Child: Care, Health and Development, 40(6), 806–824.

CHILD OUTCOMES MEASURE: SDQ 7 EARLY INTERVENTION FOUNDATION | MARCH 2020

He, J.P., Burstein, M., Schmitz, A., & Merikangas, K.R. (2013). The Strengths and Difficulties Questionnaire (SDQ):
The factor structure and scale validation in US adolescents. Journal of Abnormal Child Psychology, 41(4),
583–595.
Hessel, H., He, Y., & Dworkin, J. (2017). Paternal monitoring: The relationship between online and in-person
solicitation and youth outcomes. Journal of Youth and Adolescence, 46(2), 288–299.
Humphrey, N., Lendrum, A., & Wigelsworth, M. (2010). Social and emotional aspects of learning (SEAL) programme
in secondary schools: National evaluation. London: Department for Education.
Keating, A., Sharry, J., Murphy, M., Rooney, B., Carr, A. (2016). An evaluation of the parents plus–Parenting when
separated programme. Clinical Child Psychology and Psychiatry, 21(2), 240–254.
Little, M., Berry, V. L., Morpeth, L., Blower, S., Axford, N., Taylor, R., Bywater. T., Lehtonen, M., & Tobin, K. (2012).
The impact of three evidence-based programmes delivered in public systems in Birmingham, UK. International
Journal of Conflict and Violence, 6(2), 260–272.
Mandy, W., Murin, M., Baykaner, O., Staunton, S., Cobb, R., Hellriegel, J., Anderson, S., & Skuse, D. (2016). Easing
the transition to secondary education for children with autism spectrum disorder: An evaluation of the Systemic
Transition in Education Programme for Autism Spectrum Disorder (STEP-ASD). Autism, 20(5), 580–590.
Mathai, J., Anderson, P., & Bourne, A. (2003). Use of the Strengths and Difficulties Questionnaire as an outcome
measure in a child and adolescent mental health service. Australasian Psychiatry, 11(3), 334–337.
Mark, K.M., & Pike, A. (2017). Links between marital quality, the mother-child relationship and child behavior: A
multi-level modeling approach. International Journal of Behavioral Development, 41(2), 285–294.
Nitsch, E., Hannon, G., Rickard, E., Houghton, S., & Sharry, J. (2015). Positive parenting: A randomised controlled
trial evaluation of the Parents Plus Adolescent Programme in schools. Child and Adolescent Psychiatry and
Mental Health, 9(1), 43.
Palmieri, P. A., & Smith, G.C. (2007). Examining the structural validity of the Strengths and Difficulties
Questionnaire (SDQ) in a U.S. sample of custodial grandmothers. Psychological Assessment, 19(2), 189–198.
Rothenberger, A., & Woerner, W. (2004). Strengths and Difficulties Questionnaire (SDQ) – Evaluations and
applications. European Child & Adolescent Psychiatry, 13(Suppl2), 111–112.
Stone, L. L., Otten, R., Engels, R.C., Vermulst, A.A., & Janssens, J.M. (2010). Psychometric properties of the parent
and teacher versions of the strengths and difficulties questionnaire for 4- to 12-year-olds: A review. Clinical Child
and Family Psychology Review, 13(3).
Terrelonge, D.N., & Fugard, A.J. (2017). Associations between family and clinician ratings of child mental health: A
study of UK CAMHS assessments and outcomes. Clinical Child Psychology and Psychiatry, 22(4), 664–674.
Tsang, K.L.V., Wong, P.Y.H., & Lo, S.K. (2012). Assessing psychosocial well-being of adolescents: A systematic
review of measuring instruments. Child: Care, Health and Development, 38(5).
Vostanis, P. (2006). Strengths and Difficulties Questionnaire: Research and clinical applications. Current Opinion in
Psychiatry, 19(4), 367–372.
Warnick, E.M., Bracken, M.B., & Kasl, S. (2008). Screening efficiency of the Child Behavior Checklist and Strengths
and Difficulties Questionnaire: A systematic review. Child and Adolescent Mental Health, 13(3), 140–147.

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First published in March 2020. © 2020

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