Obsessive-Compulsive Disorder (OCD) is characterized by recurrent, intrusive thoughts (obsessions) and repetitive behaviors (compulsions). This article reviews neurobiology and treatment.
EPIDEMIOLOGY
- Lifetime prevalence: 2-3%
- Equal gender distribution
- Mean age of onset: 19 years
- Bimodal distribution (childhood onset and early adulthood)
CLINICAL PRESENTATION
Obsessions
- Recurrent, persistent thoughts, urges, or images
- Intrusive and unwanted
- Cause marked anxiety or distress
- Person attempts to ignore or suppress them
Common themes
- Contamination
- Symmetry/ordering
- Forbidden/taboo thoughts
- Harm
Compulsions
- Repetitive behaviors or mental acts
- Performed in response to obsession or rigid rules
- Aimed at preventing distress or dreaded outcome
- Clearly excessive or not realistically connected
Common compulsions
- Washing/cleaning
- Checking
- Ordering/arranging
- Mental rituals (counting, praying)
NEUROBIOLOGY
Circuit dysfunction
- Cortico-striato-thalamo-cortical (CSTC) loop hyperactivity
- Orbitofrontal cortex hyperactivity
- Anterior cingulate cortex involvement
- Basal ganglia abnormalities
Neurotransmitters
- Serotonin dysfunction (basis for SSRI treatment)
- Glutamate involvement
TREATMENT
Exposure and Response Prevention (ERP)
- Gold standard psychotherapy
- Systematic exposure to feared stimuli
- Prevention of compulsive response
- 60-80% response rate
Pharmacotherapy
First-line: SSRIs at high doses
- Fluoxetine: 40-80 mg
- Sertraline: 200 mg
- Fluvoxamine: 200-300 mg
- Paroxetine: 40-60 mg
Timeline: 8-12 weeks for adequate trial
Secondline
- Clomipramine (most effective, more side effects)
Augmentation
- Atypical antipsychotics (risperidone, aripiprazole)
TREATMENTRESISTANT OCD
Consider
- Combination ERP + medication
- Clomipramine
- Augmentation with antipsychotic
- Deep Brain Stimulation (FDA approved for severe cases)
- Gamma knife capsulotomy (rarely)
RELATED CONDITIONS
- Body Dysmorphic Disorder
- Hoarding Disorder
- Trichotillomania
- Excoriation Disorder
- PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections)
PROGNOSIS
- Chronic condition without treatment
- With ERP + medication: 60-80% significant improvement
- Maintenance treatment often needed
- Early treatment improves outcomes