AQA A-Level Psychology: Paper 1 - Introductory Topics

Baddeley & Hitch (1974) proposed the Working Memory Model (WMM) as a more detailed alternative to the unitary STM of the MSM. WMM views STM as an active processing system with multiple components.

Dual-task evidence: participants can perform two tasks simultaneously if they use different components (e.g. one visual + one verbal task), but performance drops sharply when both tasks use the same component (e.g. two visual tasks).

Evaluation:

• Case study support: Shallice & Warrington (1970) - patient KF had brain damage; his verbal STM (phonological loop) was impaired but visual STM (sketchpad) intact - supports the separate components.
• Dual-task experiments: Baddeley et al. (1975) - participants found it harder to do two visual tasks at once than one visual + one verbal - supports the existence of separate slave systems.
• Word-length effect: Baddeley et al. (1975) - participants remembered fewer long words (multi-syllable) than short ones in immediate recall - reflects the 2-second articulatory loop capacity.
• Central executive is vague: the central executive has not been well-defined or measured; Baddeley himself (2003) said it is the most important but least understood component.
• Lack of clarity on episodic buffer: the buffer was added late (2000) to explain things WMM could not - somewhat ad hoc.
• Lab studies vs everyday memory: dual-task evidence largely comes from artificial tasks; real-world generalisation is debated.

Interference theory: forgetting occurs because one memory blocks the recall of another, causing distortion or forgetting. More likely when memories are similar.

Key study - McGeoch & McDonald (1931): participants learned a list of 10 words to perfect recall, then learned a second list. Recall of the first list was tested. The more similar the second list to the first (synonyms most similar; numbers most different), the worse the recall of the first list - showing interference is greatest when memories are similar.

Evaluation:

• Strong evidence from lab studies: thousands of lab studies support interference as a cause of forgetting in STM and LTM.
• Real-world support: Baddeley & Hitch (1977) - rugby players who had played the most games during a season remembered fewer team names than those who played fewer (similar memories interfering).
• Artificial materials: word lists are very different from real-life memories; lab tasks may exaggerate interference effects.
• Time intervals: typical lab studies present material in close succession, which is rare in real life - interference may be less important outside the lab.
• Interference is temporary - retrieval may work: Tulving & Psotka (1971) - cued recall reversed apparent interference effects, suggesting memories are accessible but not retrievable - challenges interference as a complete explanation.

Retrieval failure due to absence of cues: forgetting occurs not because the memory has gone, but because the right retrieval cues are unavailable. Tulving's Encoding Specificity Principle (1983): a cue must be present at encoding and at retrieval, and the closer the cue to the encoded form, the better the recall.

Evaluation:

• Strong supporting evidence: both Godden & Baddeley and Carter & Cassaday provide controlled experimental support. Eysenck (2010) called retrieval failure the main reason for forgetting in LTM.
• Real-world application: the cognitive interview (Fisher & Geiselman) uses context reinstatement to improve EWT recall - a practical application.
• Recall vs recognition: Godden & Baddeley (1980) repeated the study using recognition rather than recall - the context effect disappeared. Suggests retrieval failure applies only to recall, limiting the theory.
• Context effects can be artificial: Baddeley (1997) noted that everyday contexts rarely differ as dramatically as land vs underwater, so context effects may be exaggerated in lab studies.
• Encoding specificity is circular: the only way to know whether a cue was encoded is to test recall - making the theory hard to falsify (Nairne, 2002).

Eyewitness testimony (EWT): the ability of people to remember the details of events they have observed, such as accidents and crimes. EWT is influenced by misleading information.

Loftus & Palmer (1974) - speed estimates and the leading question study:

Experiment 1: 45 American students watched 7 short film clips of car accidents and were asked: "About how fast were the cars going when they ___ each other?" The verb varied:

Experiment 2: a week later, participants who had heard "smashed" were significantly more likely to report (falsely) seeing broken glass than those who heard "hit". Concluded that misleading information can alter the actual memory (substitution explanation), not just bias the response.

Two ways misleading information affects EWT:

Evaluation:

• Real-world application: Loftus's work has changed how police forces and the legal system treat eyewitness testimony, including the design of police interviews.
• Artificial tasks: watching film clips lacks the emotional impact of real crime; Loftus & Palmer's participants may have lacked the engagement of a true witness.
• Individual differences - age: Anastasi & Rhodes (2006) found people are more accurate when identifying people of their own age (own age bias). Children and the elderly are more susceptible to misleading information than young adults.
• Demand characteristics: Zaragoza & McCloskey (1989) argued participants in Loftus's studies may have given the answer they thought the experimenter wanted, especially in forced-choice questions.
• Contradictory real-world evidence: Yuille & Cutshall (1986) - real witnesses to a violent armed robbery in Vancouver gave accurate accounts 4 months later and were not affected by misleading questions, suggesting lab studies overestimate the effect.

Anxiety has both positive and negative effects on EWT - findings appear contradictory.

The Yerkes-Dodson Law (1908) - inverted-U explanation:

Anxiety affects performance in an inverted U-shape: low anxiety = low recall; moderate anxiety = optimum recall; very high anxiety = decline in recall. Deffenbacher (1983) applied this to EWT, suggesting moderate stress aids recall but extreme stress impairs it.

Evaluation:

• Support for negative effect: Loftus et al. (1987) used eye-tracking to confirm participants spent more time looking at a weapon than at the person holding it - supporting weapon focus.
• Field studies have higher ecological validity: Yuille & Cutshall studied real eyewitnesses; results contradict lab findings.
• Pickel (1998): argued weapon focus is due to unusualness, not anxiety - participants showed worse identification when a man held a raw chicken (unusual but not threatening) than scissors (usual in context). Questions whether anxiety itself is the cause.
• Yerkes-Dodson is over-simplistic: assumes only one dimension of anxiety; in reality, EWT involves cognitive, emotional, and physiological factors.
• Ethical issues: deliberately creating anxiety in participants raises concerns; field studies of real witnesses avoid this but suffer from less control.

The cognitive interview (CI) developed by Fisher & Geiselman (1992) is a research-based technique designed to improve EWT accuracy. It is based on cognitive principles of memory.

Four main techniques:

Enhanced cognitive interview (ECI): Fisher et al. (1987) added social components - building rapport with the witness, minimising distractions, letting the witness speak slowly, asking open questions.

Evaluation:

• Strong meta-analytic evidence: Köhnken et al. (1999) meta-analysis of 53 studies found CI gave 34% more correct information than the standard police interview.
• Increase in incorrect information: the same meta-analysis found CI also increased incorrect details; Köhnken et al. (1999) noted accuracy rates were 84% for CI vs 82% for standard - similar in proportional accuracy, but more material overall.
• Some elements are more effective: Milne & Bull (2002) - combining "report everything" and "reinstate context" produced the best recall; "reverse the order" and "change perspective" added little. May not need all four.
• Time and training-intensive: CI takes much longer than a standard interview; many police forces only use parts. Lack of training and lack of time make full implementation difficult.
• Children: Geiselman (1999) noted children under 6 may find "change perspective" too difficult cognitively, suggesting CI is less suitable for very young witnesses.

Lorenz (1935) - geese and imprinting:

Procedure: divided a clutch of greylag goose eggs into two groups. Half hatched naturally with the mother; the other half hatched in an incubator with Lorenz as the first moving object they saw.

Findings: the incubator group followed Lorenz everywhere, even after being mixed with the mother-reared group. Lorenz called this imprinting: animals attach to and follow the first moving object they see during a critical period (~13-16 hours after hatching). Imprinting is irreversible and affects sexual imprinting in adulthood (a male peacock raised with tortoises later only mated with tortoises).

Harlow (1958) - rhesus monkeys and contact comfort:

Procedure: 16 infant rhesus monkeys raised with two "surrogate mothers": a wire mother (uncomfortable, dispensed milk) and a cloth-covered mother (comfortable, no milk). Time spent with each was measured.

Findings: monkeys spent most of their time with the cloth mother (~17-18 hours a day vs ~1 hour with the wire mother), going to the wire mother only briefly to feed. When frightened (by a mechanical "monster"), they ran to the cloth mother for comfort. Harlow concluded that attachment is based on contact comfort, not feeding (contradicting cupboard-love theory).

Long-term effects: the cloth-reared but isolated monkeys grew up with severe consequences: socially abnormal, unable to form normal relationships, abusive or neglectful as mothers themselves. Harlow proposed a critical period of 90 days - after which deprived monkeys could not recover normal social functioning.

Evaluation:

• Lorenz - imprinting is more flexible than thought: Guiton et al. (1966) - chicks imprinted on yellow rubber gloves later tried to mate with them but could be reversed through training - challenges Lorenz's claim of irreversibility.
• Generalisation to humans is limited: birds attach differently from mammals. Humans show emotional responses to attachment figures and are not "imprinted" in the same way.
• Harlow's theoretical impact: profoundly influential - shifted theory from feeding/cupboard-love (learning theory) to comfort/relationship-based attachment.
• Harlow's real-world value: Howe (1998) - findings helped social workers and clinical psychologists understand neglect; informed care of caged primates.
• Severe ethical issues with Harlow: monkeys suffered lifelong psychological harm. Harlow himself called the wire mothers "iron maidens". Question of whether the ends justified the means; some argue findings could not have been obtained otherwise.
• Generalisation to humans: rhesus monkeys are more similar to humans than geese, but they are still not human; cultural and cognitive factors complicate the picture.

Learning theory of attachment - "cupboard love": proposed by behaviourists (e.g. Dollard & Miller, 1950). Babies become attached to their caregiver because the caregiver provides food.

Drive reduction: hunger is a primary drive (biological); the caregiver becomes associated with food and so becomes a secondary reinforcer. Attachment is acquired because the caregiver becomes the source of reward.

Evaluation:

• Contradicting evidence - Harlow (1958): rhesus monkeys preferred a cloth mother that gave no food over a wire mother that did - directly contradicts learning theory.
• Contradicting evidence - Schaffer & Emerson (1964): many babies' primary attachment was not to the person who fed them but to the most responsive caregiver.
• Some elements may apply: conditioning may still play a role in associating caregivers with comfort and care - learning theory is not entirely wrong, but is insufficient as a complete explanation.
• Reductionist: reduces a complex emotional bond to simple stimulus-response learning; ignores cognitive and emotional aspects.

Bowlby (1969) proposed an evolutionary theory of attachment, rejecting learning theory. Key features can be remembered as ASCMI:

The continuity hypothesis: there is consistency between early attachment and emotional behaviour later in life. The internal working model also influences parenting style in adulthood, explaining the intergenerational transmission of attachment patterns.

Evaluation:

• Research support for monotropy & sensitive period: Bailey et al. (2007) - mothers with poor attachments to their own mothers had children classified as poorly attached. Supports the internal working model and intergenerational transmission.
• Research support for social releasers: Brazelton et al. (1975) - when caregivers were instructed to ignore babies' social releasers, the babies first protested, then became listless and motionless - showing social releasers are important.
• Challenge to monotropy: Schaffer & Emerson (1964) - many babies formed multiple attachments simultaneously; some formed primary attachment to someone other than the mother. Rutter (1995) argued all attachments are equivalent, not arranged in a hierarchy.
• Socially sensitive: the law of accumulated separation may make working mothers feel guilty. Bowlby's emphasis on the mother as primary attachment has been used to argue against women working outside the home.
• Critical/sensitive period - too rigid? Rutter's Romanian orphans study showed some children could develop attachments after age 2 - suggests the period is sensitive (more flexible) rather than strictly critical.

Ainsworth (1970) - the Strange Situation: a controlled observation designed to measure the security of attachment in 12-18-month-old infants.

Procedure: 100 middle-class American infants observed through a one-way mirror in a lab. Eight episodes of 3 minutes each: (1) baby + mother in unfamiliar room; (2) stranger enters; (3) mother leaves; (4) mother returns, stranger leaves; (5) mother leaves; (6) baby alone; (7) stranger returns; (8) mother returns.

Behaviours measured:

• Proximity-seeking - infant stays close to caregiver
• Exploration and secure-base behaviour - infant uses caregiver as a base to explore
• Stranger anxiety - distress when stranger appears
• Separation anxiety - distress when caregiver leaves
• Response to reunion - how infant behaves when caregiver returns

Findings - three attachment types:

Caregiver sensitivity hypothesis: securely attached infants have caregivers who are sensitive to their needs; insecure attachments result from less sensitive parenting.

Evaluation:

• High reliability: Bick et al. (2012) - inter-rater agreement was 94%; the Strange Situation produces consistent results when raters are trained.
• Predictive validity: securely attached children have better outcomes in childhood (Kokkinos, 2007 - less bullying) and adulthood (Hamilton, 2000 - better romantic relationships) - supports the internal working model.
• Culture-bound: based on Western, individualist assumptions. Takahashi (1990) - Japanese infants showed high resistant attachment because they are rarely separated from mothers - the Strange Situation was so distressing they had to stop early.
• Limited types: Main & Solomon (1986) identified a fourth type - disorganised (Type D) - inconsistent, contradictory behaviour, often associated with abuse.
• Ethical issues: deliberately causes distress in infants; some argue this is unjustifiable.

van IJzendoorn & Kroonenberg (1988): a meta-analysis of 32 studies using the Strange Situation, involving 1,990 infants across 8 countries. Looked at proportions of secure, avoidant, and resistant attachment.

Findings:

• Secure attachment was the most common in every country, ranging from 50% in China to 75% in Britain.
• Insecure-avoidant was most common in individualistic Western cultures - Germany (35%) highest, reflecting parenting that values independence.
• Insecure-resistant was most common in collectivist cultures - Japan (27%) and Israel, reflecting parenting that promotes closeness.
• Variation within countries was 1.5× greater than variation between countries.

Conclusion: secure attachment is the universal norm, suggesting attachment is innate and biological (supports Bowlby). However, cultural practices do influence attachment styles - so both nature and culture matter.

Evaluation:

• Large sample: 1,990 infants increases internal validity and statistical power.
• Imposed etic: using the Strange Situation (designed in the US) to study other cultures imposes a Western standard - separation may have different meanings in different cultures.
• Non-representative samples: many of the 32 studies came from small subcultures; e.g. only 36 children in the Chinese sample - cannot claim true national representativeness.
• Confounding variables: different studies had different methodological standards (e.g. observer training); within-culture sub-cultural differences (e.g. urban vs rural) may have skewed national figures.
• Cross-cultural meaning of behaviour: Takahashi (1990) noted Japanese mothers were observed grabbing the infant on reunion to comfort them - what looks like "resistance" may simply be a different cultural way of seeking comfort.

Bowlby (1951): "Mother-love in infancy and childhood is as important for mental health as are vitamins and proteins for physical health."

Maternal deprivation hypothesis: being separated from a primary attachment figure (typically the mother) for prolonged or repeated periods during the critical period (first 2.5 years; possibly up to age 5) causes serious psychological harm.

Distinction: separation = brief; deprivation = prolonged or repeated, leading to loss of emotional care.

Effects of maternal deprivation:

Bowlby (1944) - 44 thieves study: 44 juvenile thieves and a control group of 44 non-criminal but emotionally disturbed young people. Bowlby interviewed each and their families.

Findings: 14 of the 44 thieves showed signs of affectionless psychopathy; 12 of these 14 had experienced prolonged separation from their mother in their first two years. In the control group, only 2 had experienced separation. Concluded that early separation causes affectionless psychopathy and delinquency.

Evaluation:

• Influential evidence: 44 thieves study had significant impact on childcare policy, e.g. children's hospital visiting arrangements.
• Methodological problems with 44 thieves: Bowlby conducted the interviews and the diagnoses himself - researcher bias. Data were retrospective and based on memory, lacking reliability.
• Confounding deprivation and privation: Rutter (1981) argued Bowlby confused deprivation (loss of an attachment) with privation (never forming one). Many of Bowlby's "deprived" children may never have formed attachments - privation has worse and different effects.
• Contradictory evidence: Lewis (1954) replicated the 44 thieves with 500 young people - found no relationship between maternal deprivation and criminality.
• Critical period is too rigid: Koluchová (1976) studied Czech twins who suffered severe deprivation from 18 months to 7 years and showed remarkable recovery - suggesting the effects are not always irreversible.
• Socially sensitive: theory has been used to argue against women working outside the home and using nursery care.

Romanian orphans: in the 1990s, following the fall of Ceauşescu, ~100,000 children were found in poor Romanian institutions. Many were later adopted internationally - allowing researchers to study the effects of institutionalisation and recovery.

Rutter et al. (2011) - English and Romanian Adoptee (ERA) study: followed 165 Romanian orphans adopted by British families. Tested at ages 4, 6, 11, 15. Compared with 52 British adoptees as controls.

Findings:

• At arrival, half the Romanian children showed delayed intellectual development and most were undernourished.
• By age 4: those adopted before 6 months showed normal IQ (mean 102); those adopted between 6 months and 2 years had IQ 86; those adopted after 2 years had IQ 77.
• Frequency of disinhibited attachment (overly friendly to strangers, attention-seeking) was common in those adopted after 6 months.

Zeanah et al. (2005) - Bucharest Early Intervention Project (BEIP): 95 institutionalised Romanian children (aged 12-31 months) vs 50 non-institutionalised controls. Strange Situation results: 74% of controls showed secure attachment vs only 19% of institutionalised children; 65% of institutionalised showed disorganised attachment.

Effects of institutionalisation:

Evaluation:

• Real-life application: findings led to changes in care of orphans - emphasis on a small number of consistent caregivers (key worker system); discouragement of large institutions.
• Fewer extraneous variables: Romanian orphans had not experienced trauma other than institutionalisation - so effects can be more directly attributed to institutional care than in war orphan studies.
• Lack of generalisability: Romanian institutions had unusually poor standards (severe deprivation of stimulation); other institutional experiences may be less damaging.
• Children not randomly assigned: the children adopted earliest were often more socially engaging - which may explain better outcomes - rather than age of adoption alone.
• Ongoing research: long-term effects still being studied; some impacts may emerge later in life.

The internal working model (Bowlby) hypothesises that the quality of early attachment shapes a child's expectations of future relationships across the lifespan.

Evaluation:

• Research support: Fearon & Roisman (2017) review found early attachment consistently predicted later development, especially insecure-avoidant patterns.
• Mixed findings - not always deterministic: Zimmerman et al. (2000) - childhood attachment was not a good predictor of attachment to parents in adolescence; major life events (parental divorce, bereavement) had more influence.
• Methodological problems: most studies (e.g. Hazan & Shaver) rely on self-report questionnaires - retrospective and subject to social desirability and recall bias.
• Determinism vs probabilism: early attachment predicts later outcomes but does not determine them; many insecurely attached children form good relationships later.
• Socially sensitive: labelling people as having a "type" of attachment may be self-fulfilling and damaging.

Phobia (DSM-5): a persistent, irrational fear of an object or situation that is out of proportion to the actual danger. DSM-5 categories include specific phobia (animals, objects), social anxiety (social situations), agoraphobia (public spaces/leaving home).

Two-process model (Mowrer, 1947) - the behavioural explanation:

Evaluation of two-process model:

• Real-world application: explains why exposure therapies (e.g. flooding) work - they prevent avoidance and so the maintained reinforcement is broken.
• Supporting evidence: Little Albert (1920); Sue et al. (1994) - 50% of patients with arachnophobia recall an initial traumatic experience with a spider.
• Incomplete explanation: some phobias appear without any traumatic experience; some traumatic experiences do not lead to phobias. Bounton (2007) argued the model ignores cognitive aspects (irrational beliefs).
• Biological preparedness (Seligman, 1971): humans are evolutionarily prepared to fear certain stimuli (snakes, spiders, heights) more than others (cars, guns) - the two-process model doesn't explain this.
• Cognitive characteristics ignored: phobias involve irrational thoughts not just learned responses - cognitive approach better at explaining these.

Evaluation:

• Effective for SD: Gilroy et al. (2003) followed 42 patients with spider phobia after 3 × 45-minute SD sessions; at 3 and 33 months were less fearful than a control group. Evidence of long-term effectiveness.
• Effective for flooding: Ougrin (2011) found flooding can be at least as effective as cognitive therapies in many cases - and quicker (1 session vs 10+ for SD).
• Acceptable to patients - SD: low attrition rates; clients comfortable with gradual approach.
• Traumatic - flooding: high attrition rates; some patients drop out due to severe distress. Schumacher et al. (2015) - both patients and therapists rated flooding as more stressful than SD.
• Less effective for complex phobias: social phobias may have a cognitive component that requires CBT - behavioural treatments alone may be less effective.
• Symptom substitution: some critics argue treating only the behavioural symptom leaves underlying causes; however, this concept is not well-supported empirically.

Depression (DSM-5 - major depressive disorder): a mood disorder characterised by low mood and energy.

Beck (1967) - cognitive triad & negative schemas:

Beck argued people prone to depression have three cognitive vulnerabilities:

1. Faulty information processing - selective attention to negative aspects of a situation; absolutist thinking.
2. Negative self-schemas - a fixed, negative view of the self ("I am worthless") that filters all information.
3. The negative triad - negative views of (a) the self ("I am useless"), (b) the world ("everything is against me"), and (c) the future ("things will never get better").

Ellis (1962) - ABC model:

Ellis proposed depression results from irrational beliefs. The model:

• A = Activating event (something happens, e.g. failed exam)
• B = Beliefs about the event (rational: "I needed to study more"; irrational: "I am a failure")
• C = Consequences - the emotional and behavioural reaction. Irrational beliefs cause depression, not the events themselves.

Ellis identified common irrational beliefs - "musturbatory thinking": "I must always succeed"; "I must be loved"; "life must be fair".

Evaluation:

• Supporting evidence for Beck: Grazioli & Terry (2000) - 65 pregnant women assessed for cognitive vulnerability and post-natal depression; high cognitive vulnerability predicted depression. Clark & Beck (1999) - cognitions assessed before depression also predict it onset.
• Practical application: Beck's theory led to cognitive behaviour therapy (CBT) - a highly effective treatment.
• Doesn't explain all aspects: Beck's theory doesn't explain anger, hallucinations, or delusions found in some depressed patients.
• Ellis - partial explanation only: Ellis's model applies most to "reactive" depression (triggered by life events) and less to "endogenous" depression (no obvious trigger).
• Doesn't address biological factors: ignores genetic and neurochemical (e.g. serotonin) factors. Cognitive vulnerability may itself be biologically caused.
• Cause vs effect: negative thinking may be a symptom rather than a cause of depression.

Cognitive behaviour therapy (CBT): the most common psychological treatment for depression. Combines cognitive (challenging thoughts) and behavioural (changing behaviour) techniques. Typically 5-20 sessions.

Behavioural activation: in addition to cognitive work, CBT encourages patients to engage in enjoyable activities (exercise, hobbies, socialising) that provide positive reinforcement and challenge depressive avoidance behaviours.

Evaluation:

• Effectiveness: March et al. (2007) compared CBT, antidepressants, and combined: 81% improvement with CBT; 81% with antidepressants; 86% combined. CBT is at least as effective as drugs.
• Long-term effects: CBT addresses underlying cognition, so relapse rates can be lower than for drugs alone.
• Not appropriate for everyone: requires patient motivation and articulation; severe depression may make this impossible (need drugs first). Patients who do not articulate well may not benefit.
• Overemphasis on cognition: ignores broader social/life circumstances - homelessness, abuse, poverty - that cause depression and cannot be "thought away" (sometimes called the "blame the victim" critique).
• Therapist-client relationship: a strong therapeutic alliance may be more important than the specific CBT technique (Rosenzweig, 1936).

Obsessive-Compulsive Disorder (OCD) (DSM-5): characterised by obsessions (recurrent intrusive thoughts) and/or compulsions (repetitive behaviours performed to reduce anxiety).

Genetic explanation:

• Candidate genes linked to OCD:
  • SERT (5-HTT) gene - affects transport of serotonin; mutations linked to OCD (Ozaki et al., 2003).
  • COMT gene - regulates dopamine; some variants more common in OCD patients.
• OCD is polygenic: Taylor (2013) analysed studies and found up to 230 different genes may be involved.
• Diathesis-stress: certain genes only leave some people more vulnerable to OCD; an environmental stressor (trauma, stress) is needed to trigger the condition.
• Family/twin studies: Lewis (1936) - 37% of OCD patients had a parent with OCD; Nestadt et al. (2010): identical twins had a 68% concordance rate for OCD vs 31% for non-identical twins - supports genetic component.

Neural explanation:

• Low serotonin: reduced activity of the neurotransmitter serotonin linked to depression and mood regulation issues in OCD. Antidepressants that increase serotonin (SSRIs) reduce OCD symptoms.
• Abnormal brain circuits: the orbitofrontal cortex (OFC), caudate nucleus, and thalamus form a worry circuit. Hyperactivity in this circuit causes obsessive thoughts. The OFC detects worries; the caudate nucleus normally suppresses minor worry signals - in OCD it doesn't, so worry signals reach the thalamus and produce obsessions/compulsions.

Evaluation:

• Support for genes: high twin concordance (Nestadt et al., 2010); family studies confirm familial trend.
• Polygenic and complex: no single "OCD gene" - dozens of genes each have small effects; very hard to pin down specific genetic causes.
• Support for serotonin: SSRIs (which increase serotonin) effectively reduce OCD symptoms - suggesting low serotonin is involved.
• Support for neural circuits: PET scans show high activity in OFC/caudate of OCD patients (e.g. Saxena & Rauch, 2000).
• Cause vs effect: abnormal brain activity may be a result of OCD rather than its cause; correlation does not prove causation.
• Biological reductionism: ignores environmental triggers (trauma, stress) and cognitive aspects (irrational beliefs about responsibility for harm) - a diathesis-stress model is more comprehensive.

Drug therapy for OCD targets the serotonin system - the main biological treatment.

Evaluation:

• Effectiveness: Soomro et al. (2009) - meta-analysis of 17 trials found SSRIs significantly better than placebo at reducing OCD symptoms. About 70% of patients improved.
• Cost-effective and non-disruptive: cheap compared with psychological therapies; can be taken alongside daily life.
• Side effects: indigestion, blurred vision, loss of libido (~30% of patients). For clomipramine: weight gain, tremors, more severe side effects.
• Doesn't cure - only manages: if patient stops taking drugs, symptoms typically return - drugs are a maintenance treatment, not a cure.
• Some cases biased - publication bias: Goldacre (2013) - pharma-sponsored studies often only publish positive findings; effectiveness may be overstated.
• Combined treatments often most effective: drugs + CBT typically outperform either alone, suggesting drugs are best as part of a combined approach.