Cambridge A Level Psychology 9990: Clinical Psychology — Revision Notes

These notes condense Specialist Option 1, Clinical Psychology, of Cambridge International A Level Psychology 9990 (syllabus for 2024 to 2026). Each of the five topics has the same three-part shape: diagnose and measure, explain (biological and psychological), then treat and manage. Learn the grid below, the five key studies and the evaluation hooks, and you can answer any Paper 3 or Paper 4 question on this option.

For full explanations read the Clinical Psychology study guide first. Test yourself afterwards with the Clinical Psychology practice questions.

What does the 9990 syllabus list for Clinical Psychology?

Topic	Diagnosis and measure	Explanations	Treatments
1.1 Schizophrenia	ICD-11 positive and negative symptoms; case study; delusions via VR (Freeman et al., 2003)	Genetic; dopamine hypothesis; cognitive	Typical and atypical antipsychotics; ECT; CBT (e.g. Sensky et al., 2000)
1.2 Mood disorders	ICD-11 depressive disorder and bipolar disorder; Beck Depression Inventory	Biochemical; genetic (Oruč et al., 1997); Beck’s cognitive theory; learned helplessness/attributional style (e.g. Seligman et al., 1988)	Tricyclics, MAOIs, SSRIs; Beck’s cognitive restructuring; Ellis’s REBT
1.3 Impulse control	Kleptomania, pyromania, gambling disorder; K-SAS	Dopamine; positive reinforcement; Miller’s feeling-state theory	Drugs vs placebo (Grant et al., 2008); covert sensitisation (e.g. Glover, 1985); imaginal desensitisation (e.g. Blaszczynski and Nower, 2003)
1.4 Anxiety and fear	GAD, agoraphobia, blood-injection-injury phobia; GAD-7; BIPI (e.g. Mas et al., 2010)	Genetic (e.g. Öst, 1992); classical conditioning (Little Albert); psychodynamic (Little Hans)	Systematic desensitisation; CBT with applied tension (Chapman and DeLapp, 2013)
1.5 OCD	Obsessions and compulsions (e.g. Rapoport, 1989); MOCI; Y-BOCS	Biochemical; genetic; cognitive; operant; psychodynamic	SSRIs; ERP (e.g. Lehmkuhl et al., 2008); telephone CBT (Lovell et al., 2006)

Key terms

Term	Definition
Positive symptom	An addition to normal experience, e.g. hallucinations, delusions
Negative symptom	A loss of normal function, e.g. avolition, alogia, flat affect
Delusion of persecution	A false, fixed belief that others intend harm
Dopamine hypothesis	Excess dopamine activity or D2 sensitivity causes positive symptoms of schizophrenia
Negative triad	Beck: negative views of self, world and future
Attributional style	Habitual way of explaining events; depressive style is internal, stable, global
Manic episode	At least one week of euphoria or irritability with raised activity or energy
Kleptomania	Repeated failure to resist urges to steal items not needed for use or money
Pyromania	Repeated fire-setting without an obvious motive, with tension before and fascination with fire
Feeling-state	Miller: an intense positive feeling fixed to a specific behaviour
Covert sensitisation	Pairing an imagined act with an imagined aversive outcome
Applied tension	Tensing large muscles to raise blood pressure and prevent fainting
Reciprocal inhibition	Two incompatible states (relaxation and fear) cannot occur together
Obsession / compulsion	Intrusive unwanted thought / repetitive act performed to reduce anxiety
ERP	Exposure to a trigger while the compulsion is prevented

Which measures do you need, and how do they work?

Measure	Disorder	Format	Scoring
Beck Depression Inventory	Depression	21-item self-report	0–3 per item; higher = more severe
K-SAS	Kleptomania	Self-report, past week	Higher = more severe urges and stealing
GAD-7	Generalised anxiety	7-item self-report, last two weeks	0–3 per item; total 0–21
BIPI	Blood-injection phobia	Self-report inventory	Cognitive, physiological, behavioural responses
MOCI	OCD	30 true/false items	Checking, cleaning, slowness, doubting
Y-BOCS	OCD	10-item clinician-rated scale	0–4 per item; total 0–40

All of these produce quantitative data that can be compared before and after treatment. Self-report scales risk social desirability bias; clinician-rated scales such as the Y-BOCS reduce this but depend on inter-rater reliability.

Key studies at a glance

Study	Method and sample	Main finding	One evaluation point
Freeman et al. (2003)	Pilot study; 24 non-clinical participants in a neutral VR library	Some had persecutory thoughts about avatars; these people had higher interpersonal sensitivity and anxiety	Standardised setting, but small non-clinical sample
Oruč et al. (1997)	Genetic association; 42 bipolar I patients, 40 controls	No significant association overall; trends for 5-HT2C and 5-HTT genes in women	Only a minor susceptibility effect, so reductionist to call it the cause
Grant et al. (2008)	Data from two double-blind placebo trials; 284 gamblers	Family history of alcoholism best predicted response to opiate antagonists	Placebo control and double-blind design support validity
Chapman and DeLapp (2013)	Case study of T, a 42-year-old man who fainted at blood tests; nine sessions of manualised CBT with a SUDS fear hierarchy and applied tension	Had his own blood drawn by session 9; BAI fell from 41 to 7; gains held at 12 months	Rich detail but cannot generalise from one person
Lovell et al. (2006)	Randomised non-inferiority trial; 72 OCD patients; ten sessions	Telephone ERP as effective as face to face at six months	Real patients and random allocation; therapists not blind

Must-know comparisons

• Typical vs atypical antipsychotics: both reduce positive symptoms; typicals block D2 and carry more movement side effects; atypicals also act on serotonin and may help negative symptoms.
• Tricyclics vs MAOIs vs SSRIs: tricyclics block reuptake of serotonin and noradrenaline; MAOIs stop the enzyme breaking down monoamines (diet restrictions); SSRIs block serotonin reuptake only and are usually better tolerated.
• Beck vs Ellis: Beck targets automatic negative thoughts by testing evidence; Ellis disputes irrational beliefs, especially “musts”, using the ABC model.
• Covert sensitisation vs imaginal desensitisation: the first adds an aversive image; the second adds relaxation while imagining resisting the urge.
• Little Albert vs Little Hans: both case studies of children; one behavioural (conditioning in a lab), one psychodynamic (interpretation via the father’s reports).
• SSRIs vs ERP: drugs act fast and need little effort but symptoms may return after stopping; ERP is demanding and initially distressing but teaches a lasting skill.

Mini essay plan: “Evaluate explanations of schizophrenia” [10]

1. Genetic: twin and family evidence (Gottesman, 1991); but concordance is below 100%, so nature and nurture interact.
2. Dopamine hypothesis: drug evidence supports it, but it is reductionist and cannot easily explain negative symptoms.
3. Cognitive: explains hallucinations as misattributed inner speech; but does not say what causes the fault (could be biological).
4. Determinism: biological explanations reduce blame but imply limited control.
5. Usefulness: each explanation leads to a treatment (antipsychotics, CBT), so a combined approach is most useful.

Common mistakes and exam traps

• Writing DSM criteria from memory when the question says ICD-11; use ICD-11 wording, though Cambridge accepts other terms used appropriately.
• Confusing negative symptoms with “bad” symptoms; negative means a loss.
• Saying Oruč et al. “found the gene for depression”; they found only trends in women, in a bipolar I sample.
• Describing Grant et al. as a single trial; it pooled two trials of two different drugs.
• Describing ERP as “facing your fears” without the response prevention part.
• In a 10-mark evaluation, listing strengths and weaknesses without a conclusion or comparison.

Quick self-test

1. State the minimum duration for a depressive episode in ICD-11.
2. Name the three types of antidepressant on the syllabus.
3. What three things does Beck’s negative triad refer to?
4. What is the difference between kleptomania and ordinary theft?
5. Which variable best predicted response to opiate antagonists in Grant et al. (2008)?
6. Why does blood-injection-injury phobia need applied tension rather than relaxation?
7. What maximum score can the Y-BOCS give?
8. How many patients took part in Lovell et al. (2006)?

Answers: (1) two weeks; (2) tricyclics, MAOIs, SSRIs; (3) self, world, future; (4) items are not needed for personal use or money, and there is tension before and relief after; (5) a family history of alcoholism; (6) because people often faint from a drop in blood pressure, and tension raises it; (7) 40; (8) 72.

Frequently asked questions

How much detail do I need on the “e.g.” studies? Enough to describe the aim, method and main result in a few sentences. The five key studies need full detail because they can be asked about directly.

Can I use the same evaluation points for every disorder? The issues are similar (nature–nurture, reductionism, determinism), but examiners reward points applied to the specific disorder and study. Name the evidence each time.

Official syllabus

Cambridge International AS & A Level Psychology 9990 syllabus for 2024, 2025 and 2026, Specialist Option 1: Clinical Psychology — cambridgeinternational.org.

Related resources

• Clinical Psychology study guide
• Clinical Psychology practice questions
• Specialist Options revision notes