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Psychopathology
Year 1 / ASYear 2 / A-LevelAQA, Edexcel, OCR
A-Level Psychology revision on Psychopathology: definitions of abnormality, phobias, depression and OCD (characteristics, explanations and treatments), systematic desensitisation, CBT, SSRIs and ERP, with A* evaluation and exam practice.
🎯 Learning Objectives
Explain and evaluate four definitions of abnormality: statistical infrequency, deviation from social norms, failure to function adequately, deviation from ideal mental health (AQA 4.1.4)
Describe phobia characteristics (behavioural, emotional, cognitive) and the two-process model; evaluate systematic desensitisation and flooding (AQA 4.1.4)
Describe depression characteristics and cognitive explanations (Beck's negative triad, Ellis's ABC) with treatments (CBT, behavioural activation, SSRIs) (AQA 4.1.4)
Describe OCD characteristics and biological explanations (COMT, SLC1A1, basal ganglia, serotonin) with treatments (ERP, SSRIs) (AQA 4.1.4)
Statistical infrequency: Defining abnormality as behaviour or traits that are rare in the population (e.g. IQ below 70, 2% of people), measured objectively against a normal distribution.
Deviation from social norms: Defining abnormality as behaviour that violates the unstated rules of a society; norms are culture-specific and change over time.
Failure to function adequately: Defining abnormality by inability to cope with everyday living: distress, maladaptive behaviour, irrationality, unpredictability (Rosenhan and Seligman's seven criteria).
Deviation from ideal mental health: Jahoda's (1958) definition: abnormality is the absence of six criteria - self-attitudes, personal growth, integration, autonomy, accurate reality perception and environmental mastery.
Two-process model: Mowrer's explanation of phobias: fear is acquired by classical conditioning (neutral stimulus paired with trauma) and maintained by operant conditioning (avoidance negatively reinforces the fear).
Systematic desensitisation (SD): Behavioural therapy using counter-conditioning: an anxiety hierarchy is built, relaxation is taught, and the client works up the hierarchy until the CS no longer produces fear.
Flooding: Behavioural therapy exposing the client to their phobic stimulus at maximum intensity immediately, without avoidance, until the adrenaline-fuelled fear response extinguishes.
Negative cognitive triad (Beck): Beck's (1967) three negative views central to depression: a negative view of the self, the world and the future, produced by negative schemas and cognitive distortions.
ERP (exposure and response prevention): Behavioural treatment for OCD: exposure to the obsessive trigger while preventing the compulsive response, so anxiety declines and the compulsion extinguishes.
SSRIs (selective serotonin reuptake inhibitors): Biological drugs (e.g. fluoxetine) that block serotonin reuptake at the synapse, increasing serotonin availability to reduce depression and OCD symptoms.
📌 Key Points
Definitions: statistical (rare, IQ<70), social norms (culture-specific), failure to function (Rosenhan and Seligman), ideal mental health (Jahoda's six criteria)
Phobias: two-process model (classical acquisition, operant maintenance via avoidance), preparedness (Seligman); treatments: systematic desensitisation (hierarchy + relaxation), flooding, CBT
Treatments compared: SD (systematic, slow, effective for specific phobias), flooding (fast, high drop-out), CBT (gold standard, cognitive + behavioural), SSRIs (cheap, side effects, symptoms only)
Definitions of abnormality (AQA 4.1.4)
Statistical infrequency: behaviour or traits that are rare are abnormal - any measurable characteristic can be plotted on a normal distribution and behaviours more than two standard deviations from the mean (about 2% of people) are classed as abnormal, e.g. IQ below 70 (intellectual disability) or above 130. Deviation from social norms: behaviour violating the unstated rules of a society is abnormal - norms are culture-specific and change over time (homosexuality was classified as a disorder until 1973 in the DSM-II revision); antisocial personality disorder involves impulsive, aggressive behaviour that breaks social norms.
Failure to function adequately (Rosenhan and Seligman, 1989): abnormality is judged by the inability to cope with everyday living, signalled by observer discomfort, maladaptive behaviour, unpredictability, irrationality, personal distress and violation of moral standards; the Global Assessment of Functioning (GAF) operationalises it. Deviation from ideal mental health (Jahoda, 1958): abnormality is the absence of six criteria for positive mental health - self-attitudes (high self-esteem), personal growth (self-actualisation), integration (coping with stress), autonomy (independence), accurate reality perception and environmental mastery; lacking any criterion indicates abnormality.
Evaluation (AO3):
Statistical infrequency - strengths: objective, measurable and based on the normal distribution; useful for research and screening (IQ cut-offs guide diagnoses).
Statistical infrequency - limitations: labels desirable rarities as abnormal (high IQ); not all rare behaviours are disorders (left-handedness); arbitrary cut-offs; some disorders (mild depression) are statistically common.
Social norms - strengths/limitations: considers social context, but norms are culture-specific (hearing voices is valued in some cultures, diagnosed as schizophrenia in the UK) and change over time; risks abusing the label to control non-conformity.
Failure to function - strengths/limitations: respects the individual's own experience and captures the 'at what cost?' question, but functioning is judged subjectively (who decides?) and it risks discriminating against people who live unconventional but happy lives (e.g. extreme sports, unusual lifestyles).
Ideal mental health - strengths/limitations: positive, holistic and goal-focused (like Jahoda's humanistic background), but the criteria are so demanding that few people would qualify as 'healthy' at any one time, and the criteria are culture-bound (autonomy is a Western value).
Phobias: characteristics, explanations and treatments (AQA 4.1.4)
Characteristics of phobias: behavioural - panic (crying, running), avoidance of the phobic stimulus, endurance (staying with high anxiety); emotional - persistent, excessive and unreasonable fear and anxiety; cognitive - irrational beliefs about the stimulus (e.g. 'all dogs are dangerous'), selective attention to the threat, recognition that the fear is excessive. DSM-5 requires the fear to be persistent (6 months+) and to interfere with functioning.
Explanations: the two-process model (Mowrer, 1947) - fear is acquired by classical conditioning: a neutral stimulus (spider) is paired with a frightening unconditioned stimulus (being bitten), so the spider becomes a conditioned stimulus eliciting fear (conditioned response) - supported by the Little Albert experiment (Watson and Rayner, 1920), where a baby was conditioned to fear a white rat by pairing it with a loud noise. Fear is maintained by operant conditioning: avoiding the stimulus reduces anxiety (negative reinforcement), so the phobia persists. Preparedness (Seligman, 1971): humans are biologically prepared to fear evolutionarily relevant threats (snakes, heights, dark) rather than modern ones (cars, electrical sockets) - explaining why some phobias are far more common and why they resist extinction.
Treatments: systematic desensitisation (Wolpe, 1958) - counter-conditioning: an anxiety hierarchy (stimuli ranked from least to most feared) is built; the client is taught relaxation (reciprocal inhibition - relaxation and fear cannot coexist); the client works up the hierarchy pairing relaxation with each level until the conditioned stimulus no longer elicits fear. Flooding - immediate exposure to the most feared stimulus at maximum intensity without avoidance, until the adrenaline-driven fear response exhausts itself (extinction). CBT - exposure plus cognitive restructuring of irrational beliefs.
Evaluation (AO3):
Two-process model - strength: explains both acquisition and maintenance, and has direct application (SD targets the learned association; flooding targets avoidance) - Watson and Rayner's Little Albert supports conditioning of fear.
Two-process model - limitations: ignores cognition (irrational beliefs) - CBT addresses this; not all traumatic encounters produce phobias (Di Gallo's data on accident survivors) and not all phobias follow trauma (preparedness explains why snakes are feared more than flowers); the model cannot explain individual differences.
SD - strengths: effective for specific phobias (McGrath: ~75% of patients responded; Capafons: acrophobia patients reported lower fear); suitable for patients with learning difficulties (unlike CBT); low drop-out because exposure is gradual.
SD - limitations: slower than flooding (multiple sessions); less effective for generalized anxieties and social phobias; symptom substitution is a criticism from psychodynamic approaches (fear may resurface elsewhere).
Flooding - strengths/limitations: fast and cost-effective (Ohman found flooding more effective than SD for some phobias), but highly distressing, producing high drop-out and ethical concerns (informed consent, protection from harm); less effective for complex phobias with cognitive components.
Depression: characteristics, explanations and treatments (AQA 4.1.4)
Characteristics of depression (major depressive disorder): behavioural - low activity levels, disruption to sleep and eating, aggression/self-harm; emotional - lowered mood, anger, lowered self-esteem; cognitive - poor concentration, dwelling on the negative, absolutist thinking ('black-and-white' thinking).
Cognitive explanations: Beck (1967) - the negative triad: a negative view of the self ('I am worthless'), the world ('nothing goes right') and the future ('it will never improve'), produced by negative schemas (formed in childhood through bad experiences) and cognitive distortions (overgeneralisation, catastrophising, minimising positives), which maintain a vicious cycle of negative thinking. Ellis (1962) - the ABC model: an Activating event (failing a test) triggers irrational Beliefs ('I must succeed at everything'), producing emotional Consequences (depression); 'musturbatory' irrational beliefs (must, ought, should) cause unhealthy emotions. Learned helplessness (Seligman, 1974) - repeated uncontrollable negative events teach the person that outcomes are independent of effort, producing passivity and depression.
Treatments: CBT (Beck's cognitive therapy) - identify and challenge negative thoughts (cognitive restructuring), test irrational beliefs against reality, and use behavioural activation (planning pleasant, achievable activities) and homework ('patient as scientist'). Ellis's REBT - disputing irrational beliefs (logical, empirical, pragmatic disputation), effective argument and behavioural techniques. SSRIs (fluoxetine) - block serotonin reuptake, increasing serotonin availability; take 6-8 weeks to work; combined with CBT under NICE guidelines for best outcomes.
Evaluation (AO3):
Cognitive explanations - strengths: strong supporting evidence (Clark and Beck 2010: depressed people show biased processing), direct practical application in CBT, and they take account of the person's experience (unlike the purely biological model).
Cognitive explanations - limitations: causal direction is unclear - negative thoughts may be a consequence rather than a cause of depression (reactive depression follows real loss); some depression has clear biological bases (the 5-HTT gene, cortisol/HPA axis dysfunction), so the cognitive account is incomplete; Ellis's ABC is simplistic (ignores biological factors and context).
CBT - strengths: March et al. (2007) found CBT was as effective as antidepressants and the combination most effective; effects persist after treatment (unlike drugs), giving lower relapse; patient empowerment.
CBT - limitations: time-consuming, requires motivation and expensive training; not suitable for severe depression (patients cannot engage); individual differences - CBT suits reflective patients (suits 'inner' depression), while drug therapy suits those unable to talk.
SSRIs - evaluation: meta-analyses show moderate benefit over placebo (strongest for moderate-to-severe depression), they are cheap and less time-consuming than CBT, but side effects (nausea, insomnia, sexual dysfunction) cause discontinuation, they treat symptoms not causes (relapse common after stopping) and the placebo difference is modest for mild depression.
OCD: characteristics, explanations and treatments (AQA 4.1.4)
Characteristics of OCD (obsessive-compulsive disorder): behavioural - compulsions are repetitive (hand-washing, checking, counting) and reduce anxiety temporarily; emotional - intense anxiety and distress from obsessions and compulsions; cognitive - obsessions are intrusive, recurrent, unwanted thoughts (contamination, harm), and sufferers recognise they are irrational. OCD involves obsessions, compulsions or both; DSM-5 requires them to be time-consuming (1 hour+) or distressing.
Biological explanations: genetic - the COMT gene (regulates dopamine; a variation produces higher dopamine levels, associated with OCD) and the SLC1A1 gene (regulates serotonin transport; mutations increase OCD risk) - Nestadt et al. (2010) found OCD heritability of 68% (MZ twins ~68% concordance versus DZ ~31%, van Grootheest); neural - abnormal serotonin levels (low serotonin linked to obsessions) and dopamine over-activity; brain circuits - the basal ganglia (specifically the caudate nucleus, filtering impulses) and the orbitofrontal cortex (worry circuit, sends worry signals to the caudate): a hyperactive OFC and impaired caudate produce obsessive thoughts - Saxena et al. (2002) found higher OFC activity in OCD patients.
Cognitive explanations: sufferers have inflated responsibility (believing they can prevent harm) and thought-action fusion (believing that thinking about an action is morally equivalent to performing it) - obsessions become more distressing, and compulsions are performed to neutralise the thought; Salkovskis's model explains why rituals repeat.
Treatments: ERP (exposure and response prevention) - exposure to the obsessive trigger while preventing the compulsive response, so anxiety declines (extinction); SSRIs - increase serotonin availability (first-line drug); benzodiazepines (short-term anxiety relief, GABA enhancement) and ECT/deep brain stimulation for severe, resistant cases.
Evaluation (AO3):
Biological - strengths: twin and family studies (Nestadt 68% heritability) support genetic contribution; drug therapies targeting serotonin work for many patients, indirectly supporting the neural explanation.
Biological - limitations: MZ concordance is not 100%, so the environment always contributes; gene association studies are correlational and COMT/SLC1A1 explain only a small proportion of cases; the neural evidence is inconclusive - cause and effect are unclear (abnormal serotonin may be a consequence, not a cause, of OCD); and the biological account is reductionist (ignores cognitive and environmental factors).
Cognitive - strengths: explains individual differences in OCD symptoms (inflated responsibility varies) and has practical application (CBT targets thought-action fusion).
Cognitive - limitations: hard to test causally (thoughts precede or follow compulsions?); some sufferers lack inflated responsibility; less strong evidence than for depression.
ERP - evaluation: strong evidence of effectiveness (Albucher et al.: ERP produces large symptom reductions; NICE recommends ERP for OCD), but it is highly distressing (high drop-out), time-consuming and requires specialist training; not all patients benefit, and relapse can occur.
SSRIs for OCD - evaluation: effective for many (60% symptom reduction on average in trials), cheap and easy to administer, but side effects, 6-12 week delay, and symptoms return after stopping; combining SSRIs with ERP is most effective.
Classification, diagnosis and evaluating treatments (AQA 4.1.4)
Classification systems: the DSM-5 (American Psychiatric Association, 2013) and the ICD-11 (World Health Organization) classify mental disorders by symptom criteria. Reliability (consistency of diagnosis): inter-rater reliability - two clinicians should reach the same diagnosis; improvements in DSM-5 criteria raised reliability for some disorders, but comorbidity (diagnosing two or more disorders together, e.g. depression + anxiety) lowers reliability, since overlapping symptoms make classification ambiguous. Validity: construct validity (does the diagnosis capture the disorder as it really is?) and predictive validity (does diagnosis predict treatment response and outcome?). Culture-bound syndromes (e.g. taijin kyofusho in Japan - fear of offending others with one's body) show classification is culture-bound, and symptoms may express differently across cultures.
General evaluation of treatments (AO3) - a bank of points usable across treatment essay questions:
Psychological vs biological: psychological treatments (CBT, SD, ERP) address causes (cognitive distortions, learned associations) and produce lasting change with lower relapse; biological treatments (SSRIs, benzodiazepines) are cheaper, faster and suit patients unable to engage with talking therapies, but treat symptoms only.
Combined treatment: NICE guidelines recommend combining CBT with drug therapy for depression and OCD - March et al. (2007) found the combination most effective for adolescents.
Ethics: flooding and ERP raise protection-from-harm issues (high distress, drop-out); drugs raise informed consent (side effects) and dependency (benzodiazepines are addictive).
Methodological issues in treatment research: Randomised controlled trials (RCTs) are the gold standard but suffer from placebo effects, demand characteristics and publication bias (studies showing drug effectiveness are more likely to be published - Kirsch et al. argued placebo effects explain much of SSRI benefit for mild depression).
Individual differences: severity, patient preference and history determine treatment choice; severe depression may preclude CBT, and specific phobias suit SD/flooding more than CBT.
💡 Worked Example
Exam-style: AQA 4.1.4 (16 marks): Discuss the cognitive approach to explaining depression. Refer to Beck's negative triad and Ellis's ABC model in your answer.
Mark-scheme logic: 16-mark essay structure (AO1 = 6 marks description, AO3 = 10 marks evaluation). AO1 paragraph 1 (Beck): Beck (1967) argued depression stems from negative schemas, formed in childhood, which are activated by adverse events; schemas produce the negative cognitive triad - negative view of the self ('I am worthless'), the world ('nothing goes right') and the future ('it will never improve'); cognitive distortions (overgeneralisation, catastrophising, minimising positives) maintain the triad in a vicious cycle. AO1 paragraph 2 (Ellis): Ellis (1962) proposed the ABC model - an Activating event (failing a test) triggers irrational Beliefs ('I must succeed at everything'), producing emotional Consequences (depression); 'musturbatory' irrational beliefs cause unhealthy emotions; learned helplessness (Seligman) adds that uncontrollable negative events teach passivity. AO3 point 1 (support): Clark and Beck (2010) - depressed people show biased processing; cognitive theories underpin CBT, whose effectiveness indirectly supports the explanation. AO3 point 2 (causal direction unclear): negative thoughts may be a consequence, not a cause - reactive depression follows real loss. AO3 point 3 (biological bases): the 5-HTT gene and cortisol/HPA dysfunction show some depression is biological - cognitive account incomplete. AO3 point 4 (application): CBT derived from these models is effective (March et al. 2007 - as effective as antidepressants), supporting the theory's practical validity. AO3 point 5 (reductionism/simplicity): ABC is simplistic - ignores biology, context and individual differences; Beck's triad overlaps with Ellis's model (both may describe one phenomenon). Conclusion: cognitive explanations are well-supported and practically useful but incomplete without biological and situational factors.
❓ Practice Questions & Mark Schemes
Compare statistical infrequency, deviation from social norms, failure to function adequately and deviation from ideal mental health as definitions of abnormality. (8 marks)
Answer: Statistical infrequency: behaviour that is rare (e.g. IQ below 70) is abnormal - objective and measurable, but it labels desirable rarities (high IQ) as abnormal and depends on arbitrary cut-offs. Deviation from social norms: behaviour violating unstated societal rules is abnormal - it considers social context, but norms are culture-specific and change over time (homosexuality was classed as a disorder until 1973/1980). Failure to function adequately: abnormality is judged by distress, maladaptive behaviour and irrationality (Rosenhan and Seligman) - it respects the individual's experience, but functioning is hard to judge objectively and risks discriminating against unconventional lives. Deviation from ideal mental health: Jahoda's six criteria (self-attitudes, personal growth, autonomy, accurate reality perception, environmental mastery, integration) - positive and holistic, but the criteria are so demanding that few people would qualify as 'healthy'. Conclusion: each definition captures part of abnormality, and most clinicians combine several.
Explain the two-process model of phobias and evaluate it. (8 marks)
Answer: Mowrer (1947): fear is acquired by classical conditioning - a neutral stimulus (spider) paired with a frightening UCS (being bitten) becomes a conditioned stimulus eliciting fear; Watson and Rayner's Little Albert (1920) demonstrated conditioning of fear. Fear is maintained by operant conditioning - avoiding the stimulus reduces anxiety (negative reinforcement), so the phobia persists. Evaluation: explains both acquisition and maintenance, with direct application (SD targets the learned association, flooding targets avoidance). Limitations: ignores cognition (irrational beliefs) - CBT addresses this; not all traumatic encounters produce phobias and not all phobias follow trauma - Seligman's preparedness explains why evolutionarily relevant threats (snakes) are feared more than modern ones (cars); cannot explain individual differences; symptom substitution criticism from psychodynamic approaches.
Explain systematic desensitisation as a treatment for phobias and evaluate its effectiveness. (8 marks)
Answer: Systematic desensitisation (Wolpe, 1958) is counter-conditioning: (1) the client and therapist build an anxiety hierarchy ranking stimuli from least to most feared; (2) the client is taught relaxation techniques (reciprocal inhibition - relaxation and fear cannot coexist); (3) the client works up the hierarchy, pairing relaxation with each level until the conditioned stimulus no longer elicits fear. Strengths: effective for specific phobias (McGrath: ~75% responded; Capafons: acrophobia patients reported lower fear); suitable for patients with learning difficulties who cannot engage with CBT; low drop-out because exposure is gradual and controlled. Limitations: slower than flooding (multiple sessions); less effective for generalised anxiety and social phobias; symptom substitution possible; requires client commitment and imagination (or in vivo exposure). Conclusion: well-supported for specific phobias, best used where gradual exposure is preferred.
Evaluate the use of SSRIs (e.g. fluoxetine) in treating depression. (10 marks)
Answer: SSRIs increase serotonin availability by blocking its reuptake at the synapse. Strengths: meta-analyses show moderate benefit over placebo, they are cheaper and less time-consuming than CBT, and they suit patients unable to engage with talking therapies. Limitations: side effects (nausea, insomnia, sexual dysfunction) cause some patients to stop taking them; they take 6-8 weeks to work; they treat symptoms rather than underlying causes, so relapse is common after discontinuation; and the difference from placebo is modest for mild depression (Kirsch et al.). Evaluation: NICE guidelines recommend combining drug therapy with CBT for the best outcomes (March et al. 2007 found the combination most effective); the choice depends on severity, patient preference and history - SSRIs are most defensible for moderate-to-severe depression where they demonstrably outperform placebo.
Outline and evaluate the biological approach to explaining OCD. (16 marks)
Answer: AO1: Genetic explanation - the COMT gene (regulates dopamine; a variation produces higher dopamine, associated with OCD) and the SLC1A1 gene (regulates serotonin transport) increase risk; Nestadt et al. (2010) found OCD heritability of 68%; twin studies show higher MZ than DZ concordance. Neural explanation - abnormal serotonin (low levels linked to obsessions) and dopamine over-activity; brain circuits: a hyperactive orbitofrontal cortex (OFC, worry signals) and impaired basal ganglia/caudate nucleus (filtering) produce obsessive thoughts; Saxena et al. (2002) found higher OFC activity in OCD patients. Treatments derived: SSRIs (serotonin) and deep brain stimulation. AO3: twin/family studies support genetic contribution and SSRIs work for many, indirectly supporting the neural account. Limitations: MZ concordance is not 100%, so environment always contributes; gene associations are correlational and explain only a small proportion of cases; neural evidence is inconclusive (cause and effect unclear); the approach is reductionist, ignoring cognitive factors (inflated responsibility, thought-action fusion) and environmental triggers. Conclusion: the biological account has strong converging support but is incomplete alone.
Discuss issues of reliability and validity in the diagnosis and classification of mental disorders. (8 marks)
Answer: Reliability (consistency): inter-rater reliability requires two clinicians to reach the same diagnosis using DSM-5/ICD-11 criteria; comorbidity (e.g. depression + anxiety) lowers reliability because overlapping symptoms make classification ambiguous; self-report of symptoms also varies between patients. Validity: construct validity asks whether the diagnosis captures the disorder as it really is (heterogeneous categories), and predictive validity asks whether diagnosis predicts treatment response. Cultural issues: culture-bound syndromes (e.g. taijin kyofusho in Japan) show classification is culture-bound, and clinicians may impose Western norms - Cooper et al. found US psychiatrists diagnosed schizophrenia more often than UK psychiatrists for the same case notes. Evaluation: improvements to DSM-5 criteria have raised reliability, but diagnosis remains probabilistic; comorbidity and cultural bias are the strongest criticisms.
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