6 CLINICAL PSYCHOLOGY

Issues and debates

Idiographic versus nomothetic
The case study of T is idiographic. It provides detailed insight into one client. The
therapists wrote up the study to raise awareness of the potential benefits of AT to
other clients, not to make generalisations to all BII phobics and all CBT/AT therapists.

SKILLS BUILDER
Question 6.48 below is a ‘Plan a study’ question. In DeLapp quantified T’s progress using SUDS. There
this section, you have learned about the key study is another clue in the question that should prompt
by Chapman and DeLapp (2013). You may be able to you to consider another useful area of the syllabus.
borrow ideas from this study to inspire your own. The disorder being asked about is generalised
You are asked to include details about question anxiety disorder. What can you remember about the
formats and scoring. Think about how Chapman and GAD-7?

NOW TEST YOURSELF

6.45 Outline one feature of systematic 6.48 a Plan a study using self-reports to
desensitisation as a treatment for fear-related investigate the effectiveness of cognitive-
disorders. [2] behavioural therapy for people with
6.46 Morag faints every time she sees blood. generalised anxiety disorder. Your plan
Explain how and why Morag might benefit must include details about:
from applied tension. [4] – question format (open and closed
6.47 Suggest one reason why researchers may be questions)
cautious about making generalisations from – scoring/interpretation. [10]
their findings. You should refer to one study of b Describe one piece of psychological
fear-related disorders in your answer. [2] knowledge on which your plan is based. [4]

6.5 Obsessive-compulsive disorder

6.5.1 Diagnostic criteria (ICD-11)
Symptoms of obsessive-compulsive disorder (OCD) include:
» obsessions: repetitive, persistent thoughts and images that are unwanted and
intrusive
» compulsions: repetitive behaviours, such as tapping (physical) or sub-vocal
counting (mental), often to neutralise obsessive thoughts.
For a diagnosis, these obsessions and compulsions must take up at least an hour per
day and symptoms must cause distress/dysfunction.
Insight is variable, either poor–absent or fair–good.
Relevant research: Rapoport (1989)
Aim: to investigate OCD in a teenage patient, including efficacy of drug treatments.
Methodology:
» Case study of Charles (age 14), who was obsessed with stickiness; compulsive
washing took many hours a day.
» Researcher conducted an EEG.
» He was prescribed clomipramine (a tricyclic antidepressant).
Results:
» Charles spent all night washing after the EEG due to the stickiness of the electrodes.
» Four weeks after starting clomipramine, he poured/touched honey.
» He relapsed within 12 months due to tolerance, but symptoms reduced.
Conclusions: clomipramine is effective in the short term but maintenance doses are
required to prevent relapse.
Cambridge International AS/A Level Psychology Study and Revision Guide Third Edition 125
 SKILLS BUILDER
Using research evidence, explain one way that obsessive-compulsive
disorder could affect a person’s ability to function in everyday life. [2]
By the end of this chapter, you will have learned about two children with
OCD: Charles and Jason. Everyday functioning for children typically involves
going to school, so you might want to explain how Charles’ time-consuming
compulsions made this impossible. Try to avoid giving generic information that
does not really answer the question. For example, daily medication helped
Charles to function in everyday life but this knowledge doesn’t fit this specific
question and would be unlikely to gain credit.

▼ Table 6.38 Evaluating Rapoport (1989)

Strength Weakness
Qualitative data – open question responses provided Generalisation – one 14-year-old boy may not be
detailed insight into Charles’ beliefs, such as ‘What would representative of other age groups (children often count,
happen if your washing routine was disrupted?’. check and repeat movements; adults tend to ruminate).

SKILLS BUILDER
Suggest one way a researcher could increase the reliability of data collected as
part of a case study. [2]
Reliability is an important concept and understanding ways to improve it will
also help you in ‘Plan a study’ questions. Think about Rapoport’s observations
of Charles pouring honey, for example. She could have filmed him and
asked another person to watch and record Charles’ behaviour to test for
inter-observer reliability. You could justify why your idea would increase the SKILLS
consistency of the data. Be careful not to deviate into a discussion of objectivity. BUILDER
Zoubir is a trainee
Measures clinical psychologist.
The Maudsley Obsessive-Compulsive Inventory He is testing the
validity of a new
» The Maudsley Obsessive-Compulsive Inventory (MOCI) includes 30 true and false structured interview
statements developed through interviews with 30 people with OCD. schedule to assess
» Sample item: ‘I avoid using public telephones because of possible contamination.’ the severity of OCD
» The MOCI categorises respondents into four types: cleaning, checking, slowness symptoms. Plan a
and doubting. correlational study
that will help Zoubir
The Yale-Brown Obsessive-Compulsive Scale
with this goal. [10]
» The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) uses a semi-structured
interview schedule with ten items measuring symptom severity (mild to extreme) You will need to
on a five-point scale (0–4). consider all the
general features
» An accompanying checklist can be used to diagnose OCD type.
involved in planning
» Interview duration = 30 minutes.
a study. You will also
▼ Table 6.39 Evaluating the diagnosis and measurement of OCD need to focus on how
Zoubir will measure
Strengths Weaknesses two co-variables
MOCI Reliability – 50 students completed Validity – fixed-choice questions that can be plotted
the MOCI twice one month apart; 89 force people to make a decision and on a scatter graph
per cent responses were the same. items are subjective. For example, in order to assess
‘I use an average amount of soap’ the validity of the
(average for whom?). interview schedule.
Y-BOCS Reliability – agreement was Validity – difficult to report on Can you suggest a
excellent when four interviewers symptoms in ‘the last week’ if suitable directional
assessed 40 people with OCD. symptoms were worse on some days hypothesis for
than others. Zoubir’s study?

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 6 CLINICAL PSYCHOLOGY

SKILLS BUILDER
Evaluate measures of obsessive-compulsive measures. One of the first things you will notice
disorder, including a discussion of quantitative is that, while they are both self-reports, one is a
and qualitative data. [10] questionnaire and the other is a semi-structured
interview. Both result in quantitative data though.
Read through the information in this section
This is because the MOCI interviewer rates the
about the Y-BOCS and the MOCI and create a Venn
person according to what they have said in the
diagram to pick out similarities and differences.
interview. What problems does this raise for the
This should help you to begin evaluating these
MOCI that are less problematic with the Y-BOCS?

NOW TEST YOURSELF

6.49 Explain one strength of quantitative data using why Romash may fit the diagnostic criteria
the Y-BOCS as an example. [2] for OCD. [4]
6.50 Romash has been having intimate thoughts 6.51 Explain two reasons why it may not be
about his neighbour Jessie. He feels ashamed possible to make generalisations from the
and disgusted. Romash feels better if he findings of case studies of OCD. Refer to
vigorously scrubs his bathroom but he is now relevant research in your answer. [4]
spending hours cleaning when he should 6.52 Suggest two open questions that could be
be studying. Explain one or more reasons asked to investigate the effects of OCD on
functioning in everyday life. [2]

6.5.2 Explanations of obsessive-compulsive disorder

Biological explanations
Genetic
OCD appears to be inherited:
» 37 per cent of people with OCD have a parent with OCD (Lewis, 1936).
» Concordance rates: MZ twins = 87 per cent; DZ twins = 47 per cent.
OCD is polygenic and frequency of certain alleles is more/less common in people
with OCD. For example:
» Allele 2 of the DRD4 gene is less common in people with OCD.
» Low activity allele of the COMT gene is more common in people with OCD.
» Under-expression of the SLITRK5 gene is linked to OCD.

SKILLS BUILDER
Peggy is interviewing people with obsessive-compulsive two strengths and two weaknesses of each. This
disorder to investigate whether any of their relatives question requires you to use the strengths that you
also have the same disorder and if so, whether they have learned as reasons why Peggy should use this
share similar symptoms. Peggy has asked you to help format. You will need to think carefully about the
her to think about the interview format and sampling topic of Peggy’s interviews and how the format of the
technique. Which format and technique would you interview could affect the validity and reliability of
choose? the data.
a State two reasons for your choice of interview Likewise, think about the most practical way to
format. [2] recruit a sample of people with OCD. You need
b Explain one reason for your choice of sampling to know how random, volunteer and opportunity
technique. [2] sampling affect generalisability in order to decide
The interview can have a structured, semi-structured upon the best technique. Sometimes the most
or unstructured format. You will need at least scientific is not always the most practical.

Cambridge International AS/A Level Psychology Study and Revision Guide Third Edition 127
 Biochemical
Serotonin and/or dopamine imbalance may increase OCD risk. This may be caused by
abnormalities relating to:
» presynaptic serotonin reuptake
» postsynaptic receptors, such as D4 dopamine
» enzymes such as MAO-A (see page 106).

SKILLS BUILDER
Describe the biological explanation of obsessive- explanations assume OCD is inherited’, show that
compulsive disorder. [6] you understand what inherited means. You could say
something like: ‘First-degree relatives of people with
You could discuss genetics and biochemicals here.
OCD are more likely to also have the disorder than
Show both knowledge and understanding in your
more distant relatives as they share more DNA.’
response. For example, instead of saying ‘genetic

Psychological explanations
Cognitive (thinking error)
» People with OCD find it impossible to ignore passing thoughts.
» They make a thinking error; all thoughts must be meaningful and significant.
» The thoughts themselves are not problematic; the meaning attached to them
causes distress (e.g. shame, disgust).
» Thought-action/event fusion: people believe that imagining a certain action or
event increases its probability.
» Compulsions are seen as a way of neutralising obsessive/negative thoughts.
» Personal responsibility for negative outcomes may be overestimated, leading to
anxiety.

SKILLS BUILDER
Roxy and Dana are discussing the cognitive suggest that OCD is caused by dispositional factors
explanation of obsessive-compulsive disorder. Roxy that differ between people, whereas situational
thinks it is more of an individual explanation, whereas explanations emphasise environmental cues
Dana thinks it could also be seen as a situational which trigger OCD symptoms. You need to state
explanation. Explain whether you agree more with whether you agree more with Roxy or Dana and
Roxy or with Dana. [2] give a reason. Then elaborate by stating why the
information you have presented supports either an
There is no right or wrong answer, so long as you
individual or a situational explanation.
can justify your reason. Individual explanations

Behavioural (operant conditioning)

» Compulsive behaviours develop as they help to reduce negative feelings.
» Actions are repeated as they are negatively reinforced.
Psychodynamic
» OCD symptoms are a defence mechanism. They protect the person from becoming
aware of unresolved conflicts from the unconscious mind.
» The id’s desires may be expressed through obsessional thoughts.
» Compulsive acts may result from excessive guilt generated by an overly dominant
superego.
» Unresolved conflicts stem from early childhood, specifically during the anal stage
of psychosexual development (age 1–3):
– Potty training that is too early or too harsh may result in fixation at this
stage. Obsessive traits include orderliness and perfectionism.

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 6 CLINICAL PSYCHOLOGY

SKILLS BUILDER
Compare the genetic explanation and the psychodynamic same point, using connectives such as ‘likewise’
explanation of obsessive-compulsive disorder. [4] (similarity) and/or ‘whereas’ (difference). You could
compare the explanations with regards to issues
Anywhere that you see two or more explanations in
and debates (e.g. ‘the genetic explanation is more
the syllabus, be prepared for a compare question.
reductionist because … whereas the psychodynamic
You may present either two similarities, two
approach is more holistic because … ‘) or
differences or one of each. Comparison points
applications to everyday life.
usually include both explanations within the

▼ Table 6.40 Evaluating explanations of OCD

Strengths Weaknesses
Biological Evidence – silencing the SLITRK5 gene caused Validity – exercise caution when extrapolating
compulsive grooming and hoarding behaviour in data from mice to humans. Mice can only display
mice (Shmelkov et al., 2010). compulsions; this does not explain the origin of
obsessions.
Applications – led to the development of drug Comparison – high concordance rates in
treatments, such as clomipramine (see Rapoport, family!studies can also be explained by nurture
1989, see page 125). (e.g. modelling).
Psychological Evidence – people with ‘checking-type’ OCD Unscientific – psychodynamic concepts such
reported decreased urges and distress when as id and superego are unfalsifiable; there is no
told that they were not responsible for negative evidence that people with OCD are more likely to
outcomes (Lopatka and Rachman, 1995). have experienced conflicts aged 1–3.
Applications – therapies such as exposure and Comparison – psychological explanations
response prevention (ERP; see page 130) were cannot explain genetic evidence, such as the low
developed as a result of psychological theories. frequency of allele 2 of the DRD4 gene in people
with OCD.

Issues and debates

Individual and situational explanations
All the explanations give individual accounts of OCD, focusing on the person rather
than the situation – for example, inherited genes make some people vulnerable.
Research shows that symptom severity is affected by situational factors such as
temperature (Brierley et al., 2021).
Nature versus nurture
OCD prevalence is universal, supporting nature, but there are cultural differences in
how symptoms manifest, supporting nurture (Fontenelle et al., 2004).
Psychological explanations cannot explain case studies such as Thobois et al.
(2004), in which a blood clot on the caudate nucleus led to OCD symptoms.

NOW TEST YOURSELF

6.53 Using an example, describe one ‘thinking 6.55 Explain one application to everyday life of the
error’ in people with obsessive-compulsive biochemical explanation of
disorder. [2] obsessive-compulsive disorder. [2]
6.54 Explain one similarity and one difference 6.56 You are planning a naturalistic observation
between biological and psychological to investigate the behavioural explanation
explanations of obsessive-compulsive of obsessive-compulsive disorder. Explain
disorder. You must refer to reductionism how and why a behavioural checklist could be
versus holism in your answer. [4] used in your study. [4]

Cambridge International AS/A Level Psychology Study and Revision Guide Third Edition 129
 6.5.3 Treatment and management of obsessive-
compulsive disorder
Biological treatments
» OCD is treated with medications that increase serotonin (SSRIs) and
noradrenaline (tricyclics, e.g. clomipramine; see page 106).
» Treatment-resistant patients may be prescribed risperidone (an atypical
antipsychotic; see page 96).

Psychological therapies: exposure and response prevention

» Environmental cues that trigger obsessions are identified and rated using SUDS
(see page 124). Cues are arranged into a hierarchy.
» Clients are exposed to the lowest rated cue until habituation (SUDS decreased to
50 per cent below baseline).
» Therapists prevent compulsive acts. Clients must learn to reduce anxiety in other
ways.
» Homework includes graduated exposure tasks and recording change in SUDS.
» Relaxation exercises and anti-anxiety drugs are banned. People must learn that
anxiety goes up but also comes down on its own.

Relevant research: Lehmkuhl et al. (2008)

Aim: to investigate the efficacy of CBT for a child with Autism Spectrum Disorder (ASD)
and OCD.
Methodology:
» Case study of 12-year-old Jason.
» Obsession = contamination, compulsion = handwashing.
» ASD symptoms = sensory issues, self-harm, limited and repetitive language and
play, poor social relationships.
CBT was adapted to his needs:
» The therapist used phrases like ‘not letting OCD be the boss’.
» Homework (e.g. touching elevator buttons) was reinforced using a reward chart.
» Parents and teachers were involved.
Results:
» Y-BOCS score dropped from 18 to 3.
» Three months later, Jason showed no signs of relapse.
Conclusions: CBT can be personalised for children with additional needs.
▼ Table 6.41 Evaluating Lehmkuhl et al. (2008)

Strengths Weaknesses
Validity – the study used method Case study – can only generalise with
triangulation; primary data = observation, caution. Jason had average IQ and a lot
interview, psychometric tests (IQ test of support at home/school. ERP may not
and Y-BOCS), secondary data = medical work for all children with ASD.
records.
Replicable – an RCT with 46 adults with Application – ERP may only have been
ASD supports the efficacy of ERP for this effective due to the skills of the specific
population (Russell et al., 2013). therapist; other therapists may not form
such effective therapeutic alliances.

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 6 CLINICAL PSYCHOLOGY

SKILLS BUILDER
Evaluate psychological treatments for obsessive- the efficacy of CBT and ERP. Compare the types of
compulsive disorder, including a discussion of the evidence they supply, such as the validity of Lovell
use of children in research. [10] et al. versus Lehmkuhl et al. You could also discuss
how these therapies compare to the use of SSRIs.
Now that you have almost reached the end of the
Most importantly, though, you need to address the
clinical chapter, you should be quite familiar with
named issue. Think about how the therapies can be
ways of evaluating treatments. Start by discussing
adapted for children (e.g. Lehmkuhl et al.) and why
research evidence (e.g. Lehmkuhl et al., 2008; Lovell
psychological therapies might be preferred to drug
et al., 2006). Focus on how the findings demonstrate
treatments with child patients.

Key study: Lovell et al. (2006)

Context:
» Weekly, in-person therapy is costly. Lengthy waiting lists can make it
inaccessible.
» New modes of delivery are being trialled, such as online/telephone.
Aims and hypothesis:
» Aim: to compare telephone versus face-to-face ERP treatment.
» Hypothesis: telephone ERP is not less effective than face-to-face ERP.
Research method(s) and design:
» Method/design: randomised control trial, independent measures, random
allocation, longitudinal.
» Data collection technique: questionnaires (psychometric tests).
Variables:
» Independent variable: mode of ERP delivery – telephone versus face to face.
» Dependent variable: compulsive behaviour checklist based on the Y-BOCS
(see!page 126), the BDI (see page 100) and a client satisfaction questionnaire.
Sample: opportunity sample (n = 72) of 16–65-year-old outpatients with OCD from
the UK (all scored 16+ on the Y-BOCS).
Procedure:
» Baseline symptoms were assessed by researchers twice, four weeks apart. The
researchers were unaware of each participant’s mode of delivery (i.e. blind).
» Symptoms were reassessed at one, three and six months after treatment.
» ERP was delivered by experienced therapists.
Controlled variables:
» Therapy manuals were used to standardise treatment across different therapists/
clients.
» Random allocation controlled participant variables.
» The blinding procedure eliminated researcher bias.
Ethics: protection from harm; ten people at increased risk of suicide were
deselected.
Results:
» There was no significant difference in symptom severity between the telephone
and face-to-face treatment groups before treatment or at any of the follow-up
assessments.
» Client satisfaction did not differ immediately after treatment.
» Treatment was successful for 77 per cent of the telephone group and 67 per cent
of the face-to-face group.
Conclusions: telephone ERP for OCD is as effective as face-to-face therapy, despite
50 per cent less therapist contact time.

Cambridge International AS/A Level Psychology Study and Revision Guide Third Edition 131
 SKILLS BUILDER
a Plan a randomised control trial to test the For example, the researchers used an independent
effectiveness of SSRIs as a treatment for measures design with random allocation. You could
obsessive-compulsive disorder. Your plan must randomly allocate your participants to either the
include details about controlled variables and SSRI group or a control group.
a directional or non-directional hypothesis. [10]
You could use a study from another part of the
b For one piece of psychological knowledge on chapter to help you if you wish. For example,
which your plan is based: Grant et al. (2008) compared opiate antagonists
i Describe this psychological knowledge. [4] (for gambling disorder) with a placebo group. You
ii Explain how you used two features of this could also use placebos in your study. For part
psychological knowledge to plan your b, think carefully whether you would rather write
experiment. [4] about Lovell et al. or Grant et al. Think about the
Try to identify a study you have learned about with similarities between their study and the one you are
the same research method. This will provide you with planning. You will need two identifiable features that
ideas for your own study. Lovell et al. (2006) is an RCT inspired your planning – for example, double-blind
comparing two modern versions of ERP. You can use design, use of a psychometric test (e.g. Y-BOCS).
some of the design features to help plan your study.

▼ Table 6.42 Evaluating Lovell et al. (2006)

Strengths Weaknesses
Reliability – baseline measures were taken twice Validity – the blinding procedure broke down for 13 per cent of
(test-retest). participants, reducing validity due to possible researcher bias.
Validity – random allocation reduced the effect of Longitudinal design – 11 people dropped out. Attrition can lead
participant variables, such as symptom severity, to differences in key participant variables between the groups,
employment and marital status. reducing validity and generalisability.

SKILLS BUILDER
Explain why random allocation was used to assign of people receiving telephone versus face-to-face
participants to the two groups in the key study by ERP). Can you think of any individual differences
Lovell et al. (2006) about telephone-administered that might have caused the average to be higher
cognitive-behavioural therapy. [2] in one group than the other (besides the type of
therapy)? Random allocation would mean that any
If you are unsure about any of the methodological
difference in the Y-BOCS averages is more likely
concepts mentioned, revisit them now (e.g. for
to be due to the type of therapy (the independent
random allocation, see page 59). Link your ideas to
variable) than participant variables, such as
specific details from the study. Think about what
comorbid disorders, age or gender.
was being measured (i.e. average Y-BOCS scores

▼ Table 6.43 Evaluating treatments for OCD

Strengths Weaknesses
Biological Evidence – a meta-analysis of RCTs showed that Individual differences – up to 60 per cent of
17 real drugs were superior to placebos. people report no improvement.
Comparison – low commitment and effort Applications – improvement can take 12 weeks;
compared with psychological therapies, also maintenance doses may be required to prevent
cheaper and therefore more accessible. relapse.
Psychological Supporting evidence – see Lehmkuhl et al. Applications – difficult to deliver for
(2008) and Lovell et al. (2006), both below. inexperienced therapists who sometimes fail to
include relatives and friends, who reinforce OCD
behaviours.
Comparison – 86 per cent of ERP clients Applications – old compulsions may be replaced
achieved a clinically relevant reduction in with new ones unless the therapist is able to
symptoms, compared with 48 per cent of people reveal the core underlying fear.
taking clomipramine.

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 6 CLINICAL PSYCHOLOGY

Issues and debates

Cultural differences
Lovell et al. (2006) only tested people in the UK, an individualist culture with a low
power distance index (PDI). People from collective cultures and/or those with high
PDI may respond less favourably. However, face-to-face ERP had long-term positive
effects for men with OCD in Iran (Khodarahimi, 2009).
Use of children in research
Lehmkuhl et al. (2008) successfully adapted ERP for a child with additional needs.
A strong rapport was developed with the family/teachers to develop a personalised
plan and facilitate transfer of treatment outcomes to home/school environments.

SKILLS BUILDER
Floss is a cognitive-behavioural therapist. She is PDI culture, he might see Floss as an authority
working with Manal, who has obsessive-compulsive figure and expect her to tell him how to recover.
disorder. Explain how cultural differences between If Floss is from a low PDI culture, she might see
Floss and Manal might influence the effectiveness Manal as an equal and expect him to participate in
of the treatment she provides. [2] creating treatment goals. Once you have thought
of some ideas, re-read the question. It is about
Think about what you have learnt about the
effectiveness of treatment, so you need to think
ways cultures differ from one another, such as
about whether these differences might make the
individualism-collectivism and power distance
treatment more or less effective and why.
index. You also need to think about key features of
CBT (e.g. it is collaborative). If Manal is from a high

NOW TEST YOURSELF

6.57 When Hafiz was made redundant from his job, he began compulsively
tapping on his laptop. He taps the keys A, E, I, O, U 30 times before
sending emails or opening attachments. Hafiz’s doctor has referred him
for exposure response prevention (ERP) therapy. Explain how this might
help Hafiz to overcome his OCD symptoms. [4]
6.58 Outline one reason why Hafiz might prefer ERP to SSRIs as a treatment
for his obsessive-compulsive disorder. [2]
6.59 The Y-BOCS is often used in studies designed to investigate the
effectiveness of treatments for OCD. Explain two advantages of
using the Y-BOCS in this type of study. [4]
6.60 Describe one research method used to investigate ERP with
reference to one relevant study. [4]

Cambridge International AS/A Level Psychology Study and Revision Guide Third Edition 133