1.5 Obsessive-compulsive disorder (OCD)
- Syllabus
- 9990–2028–2029
- Topic
- 1.5
- Level
- A2
Learning objectives
1.5.1OCD criteria• 1.5.1 Diagnostic criteria for obsessive-compulsive disorder- diagnostic criteria for obsessive-compulsive disorder (ICD-11) focusing on types of obsessions and compulsions, including a study, e.g. Rapoport (1989) 'Charles'.- measures:- - Maudsley Obsessive-Compulsive Inventory (MOCI)- - Yale-Brown Obsessive-Compulsive Scale (Y-BOCS).- Relevant issues and debates and methodology for this topic include: interviews, case studies, quantitative and qualitative data, psychometrics, validity.1.5.2OCD explanations• 1.5.2 Explanations of obsessive-compulsive disorder- biological explanations:- - biochemical- - genetic.- psychological explanations:- - cognitive (thinking error)- - behavioural (operant conditioning)- - psychodynamic.- Relevant issues and debates and methodology for this topic include: individual and situational explanations, nature versus nurture, reductionism versus holism, determinism versus free-will, idiographic versus nomothetic.1.5.3OCD treatments• 1.5.3 Treatment and management of obsessive-compulsive disorder- biological treatments including the use of SSRIs.- psychological therapies including:- - exposure and response prevention (ERP), including a study, e.g. Lehmkuhl et al. (2008)- - cognitive-behavioural therapy (CBT) (exemplified by the following key study).- Key study on treatment of obsessive compulsive disorder using telephone administered cognitive- behavioural therapy (CBT): Lovell et al. (2006).- Relevant issues and debates and methodology for this topic include: individual and situational explanations, cultural differences, use of children in research, case studies, reliability.
OCD links intrusive obsessions, driven compulsions and significant cost
| ICD-11 syllabus feature | What to identify in a case |
|---|---|
| Obsessions | Repetitive, persistent, intrusive and unwanted thoughts, images or impulses linked to anxiety; attempts to ignore, suppress or neutralise them |
| Compulsions | Repetitive behaviours or mental acts driven by an obsession, rigid rule or need for completeness |
| Function | Ritual aims to reduce anxiety/prevent feared outcome but is excessive or not realistically connected |
| Threshold | Time-consuming (often more than an hour daily) or causes significant personal, family, social, educational or occupational distress/impairment |
| Range | Contamination, harm/violent images, doubt and symmetry; washing, checking, ordering, counting, repeating phrases and reviewing memories |
Case answer: identify exact intrusive content; identify exact behavioural or mental ritual; show repetition/rigidity; explain short relief or neutralisation; then connect time, distress or impaired sleep/work/social life. Neatness, preference or one repeated act without this chain is insufficient.
| Measure | Structure and use | Boundary |
|---|---|---|
| MOCI | 30 true/false self-report statements; total plus cleaning, checking, slowness and doubting/conscientiousness domains | Efficient symptom-pattern comparison but binary responses lose severity/meaning and symptom coverage is dated |
| Y-BOCS | 10 severity items: five obsession and five compulsion dimensions; each 0–4 from none through mild/moderate/severe to extreme; total 0–40 | Tracks time, interference, distress, resistance/control and treatment change; format may be clinician interview or self-report depending study |
Rapoport (1989) 'Charles' illustrates severe childhood washing rituals and functional cost rather than 'liking cleanliness'. Clomipramine brought marked relief—he could pour honey on his hands—but tolerance/relapse after about a year shows one case and temporary drug response do not settle diagnosis, cause or general efficacy.
Scores are quantitative and repeatable, but disclosure, shame, age/language and interpretation affect validity. Interviews add qualitative context yet can miss hidden intrusive thoughts. These are curriculum tools, not self-diagnosis; qualified assessment must consider alternatives and risk.
Five OCD explanations target vulnerability, appraisal, relief learning or childhood control
| Explanation | Mechanism | Evidence/boundary |
|---|---|---|
| Biochemical | Low serotonin and high dopamine activity are associated with threat/ritual regulation; oxytocin findings are mixed | SSRI response supports involvement, not a simple proven chemical cause |
| Genetic | Polygenic inherited vulnerability raises probability | Monzani: MZ 52% vs DZ 21% concordance; Lewis: 37% parents and 21% siblings; PTPRD/SLITRK3 associations are probabilistic |
| Cognitive thinking error | Inflated threat/responsibility and thought–action fusion make normal intrusions seem dangerous, producing neutralisation | Explains content and supports restructuring; appraisal may also follow symptoms |
| Behavioural operant | Compulsion gains positive consequences or, chiefly, removes anxiety temporarily (negative reinforcement), increasing repetition | Explains maintenance and ERP; does not alone explain original obsession |
| Psychodynamic | Anal-stage control conflict/fixation and reaction formation or undoing are expressed as rigid order/cleanliness rituals | Rich individual interpretation but unconscious constructs are difficult to test |
Trigger/intrusion → catastrophic appraisal and anxiety → ritual/mental neutralisation → brief relief → negative reinforcement → stronger future ritual. Biological vulnerability and learning history may affect entry/strength; no one step is a complete universal cause.
| Debate | Evaluation |
|---|---|
| Individual–situational | Genes, chemistry and appraisal are individual; triggers/reinforcement occur in situations; interaction fits variation |
| Nature–nurture | Biological models stress nature; cognitive/behavioural learning stress nurture; twin/family designs cannot fully separate shared environment |
| Reductionism–holism | Each model isolates a testable level but omits others; integrated cycle is broader |
| Determinism–free will | Neurobiology, learning and unconscious conflict constrain action; insight, ERP and cognitive change preserve agency |
| Idiographic–nomothetic | Psychodynamic formulation is personalised; scales/genetic rates seek general rules; neither alone predicts every person |
For a case, name the model, identify the exact trigger/thought/ritual or family evidence, trace its mechanism, and give one inferential limit. Praise after cleaning is positive reinforcement; anxiety relief after checking is negative reinforcement—not punishment.
High dopamine/low serotonin and familial rates are associations, not deterministic diagnosis. The behavioural explanation is strongest for ritual maintenance. Psychodynamic anal fixation is a theory-specific interpretation, not directly measured fact.
OCD treatment targets serotonin, threat appraisals and ritual relief
| Treatment | Procedure/mechanism | Main boundary |
|---|---|---|
| SSRI | Block selective serotonin reuptake, increasing synaptic availability; reduced anxiety may lower ritual urge; OCD doses may exceed depression doses under clinical supervision | Delayed/variable response, side effects/withdrawal and relapse; mechanism does not prove cause |
| ERP | Identify obsession–compulsion chain → grade triggers → expose in session/homework → prevent/reduce ritual → use coping statements → remain until anxiety falls and feared outcome is disconfirmed | Initially distressing, needs engagement, safety and personalised hierarchy; cause may remain |
| CBT | Psychoeducation and monitoring → test inflated threat/responsibility → balanced thought/plan → combine with ERP/homework and relapse preparation | Depends on comprehension, relationship, access, culture and practice |
| Evidence | Exact result and limit |
|---|---|
| Soomro SSRI meta-analysis | 17 studies, 3097 participants: SSRIs outperformed placebo and reduced Y-BOCS; group average does not predict individual/child response |
| Lehmkuhl et al. (2008) | Jason, age 12 with autism and OCD; 10 × 50-minute CBT/ERP sessions over 16 weeks; touched elevator buttons/door handles and resisted ritual with coping statements; Y-BOCS 18→3 |
| Child boundary | Early help may prevent entrenched rituals, but assent/comprehension, distress expression, parent permission, side-effect monitoring and generalisation from one child matter |
| Lovell et al. (2006) | Exact design/evidence |
|---|---|
| Aim/design | Randomised controlled non-inferiority comparison of telephone versus face-to-face CBT/ERP; no untreated group because delivery modes, not CBT efficacy, were compared |
| Participants | 72 UK outpatients from two hospitals, ages 16–65, OCD diagnosis and Y-BOCS ≥16; key severe/organic/substance/recent-medication exclusions |
| Intervention | 10 weekly sessions: telephone appointments 30 minutes with first/last one-hour face-to-face; face-to-face appointments 60 minutes |
| Measures/time | Self-report Y-BOCS, BDI, satisfaction; two pretreatment assessments then 1-, 3-, 6-month follow-up |
| Result | Six-month Y-BOCS difference −0.55 (95% CI −4.26 to 3.15); equivalent outcomes and high satisfaction; 77% telephone vs 67% face-to-face met taught clinically significant-change criterion |
| Lens | Evaluation |
|---|---|
| Reliability | Manualised same therapy, repeated standard scales and therapists across modes aid replication; tailoring/individual response reduce exact uniformity |
| Access/culture | Telephone halves appointment time and may improve remote access/privacy; technology, language, stigma and collectivist/individualist fit vary |
| Individual–situational | Personal obsessions/hierarchy and drug response are individual; delivery/exposure context is situational |
| Validity | Randomisation and active comparison support delivery equivalence; self-report, exclusions, UK services and no no-treatment group bound broader claims |
| Case/generalisation | Jason gives depth and autism adaptation; one child cannot establish nomothetic effectiveness |
ERP exposes the trigger and prevents the response; it does not prevent exposure. Telephone CBT received the same core treatment, so equivalence addresses delivery mode. These mechanisms and study outcomes are curriculum evidence, not individual medication or exposure instructions.