Clinical features
Checking (63%), washing (50%), contamination (45%), doubting (42%), bodily fears (36%), counting (36%), insistence on symmetry (31%), aggressive thoughts (28%).
Epidemiology
Mean age: 20 yrs, 70% onset before age 25 yrs, 15% after age 35 yrs. Sex distribution equal. Prevalence: 0.5 2% of general population.
Associations
Avoidant, dependent, histrionic traits (-40% of cases), antistatic / obsessive-compulsive traits (15%) prior to disorder. In schizophrenia, 45% of patients may present with symptoms of OCD schizo-obsessive's poorer prognosis). Sydenham chorea (up to 70% of cases) and other basal ganglia disorders (e.g. TS, post-encephalitic parkinsonism).
Co morbidity
Depressive disorder (70%), alcohol- and drug-related disorders, social phobia, specific phobia, panic disorder, eating disorder, tic disorder (up to 40% in juvenile OCD) or TS.
Differential diagnosis
Normal (but recurrent) thoughts, worries, or habits; anankastic PD/OCDPD, schizophrenia; phobias; depressive disorder; hypochondriasis; body dysmorphic disorder; trichotillomania.
Management
• Psychological Psychotherapy Supportive: valuable (including family members, use of groups); psychoanalytical: no unequivocal evidence of effectiveness (insight-orientated psychotherapy may be useful in some patients). Behavioural therapy Response prevention useful in ritualistic behaviour; thought stopping may help in ruminations; exposure techniques for obsessions. Cognitive therapy so far not proven effective.
• Pharmacological Antidepressants SSRIs: fluoxetine, fluvoxamine, sertraline, or paroxetine should be considered first-line (no clear superiority of any one agent, high doses usually needed e.g. 60 mg fluoxetine allow at least 12 wks for treatment response, regard as ong-term. Clomipramine (e.g. 300 mg) has specific anti-obsessional action (first-or second-line choice). MAOIs: phenelzine should be considered as third-line if patient resistant to 2 different SSRIs/or clomipramine and SSRI and there are associated panic attacks. Augmentative strategies: buspirone if marked anxiety; antipsychotic (risperidone, haloperidol, pimozide) if psychotic features, tics, or schizotypal traits; lithium if marked depression. Other possibilities include enhancing 5HT function with L-tryptophan or fenfluramine (controversialmay have serious cardiac adverse effects).
• Physical ECT consider if patient suicidal or severely incapacitated. Psychosurgery may be considered for severe, incapacitating, intractable
cases (i.e. treatment-resistant 2 antidepressants, 3 combination treatments, ECT, and behavioural therapy), where the patient can given informed consent e.g. stereotactic cingulotomy (reported up to 65% success). In theory, disrupts the neuronal loop between the orbitofrontal cortex and the basal ganglia.
Course
Often sudden onset (e.g. after stressful loss event), symptom intensity may fluctuate (contact-related/phasic) or be chronic.
Outcome
30% significantly improve, 50% show moderate improvement, but 40% have chronic or worsening symptoms. Relapse rates are high for stopping medication.
Prognostic factors
• Poor prognosis: Giving in to compulsions, longer duration, early onset, bizarre compulsions, symmetry, comorbid depression, delusional beliefs or overvalued ideas, personality disorder (esp. schizotypal PD).
• Better prognosis: Good premorbid social and occupational adjustment, a precipitating event, episodic symptoms.
Aetiology of OCD
• Neurochemical Dysregulation of the 5HT system, or 5HT/DA interaction.
• Immunological Cell-mediated autoimmune factors may be associated (e.g. against basal ganglia peptides).
• Imaging CT and MRI: bilateral reduction in caudate size. PET/SPECT: hypermetabolism in orbitofrontal gyrus and basal ganglia (caudate nuclei) that normalises following successful treatment (either pharmacological or psychological).
• Genetic Suggested by family and twin studies (7% of first-degree relatives affected, MZ: 80% DZ: 25%.), no candidate genes as yet identified.
• Psychological Defective arousal system and/or inability to control unpleasant internal states. Obsessions are conditioned (neutral) stimuli, associated with an anxiety-provoking event. Compulsions are learned (and reinforced) as they are a form of anxiety-reducing avoidance.
• Psychoanalytical Regression from Oedipal stage to pre-genital anal-erotic stage of development as a defence against aggressive or sexual (unconscious) impulses. Associated defences: isolation, undoing, and reaction formation.
