OCD
OCD (obsessive-compulsive disorder) involves intrusive, unwanted thoughts (obsessions) and repetitive behaviors performed to reduce distress (compulsions), defined per DSM-5.
Symptoms
Recurrent, intrusive thoughts, images, or urges that cause significant anxiety, paired with repetitive behaviors or mental acts (checking, washing, counting, ordering) performed to neutralize that anxiety -- often taking more than an hour a day.
Causes and risk
A combination of genetic, neurobiological (involving cortico-striato-thalamo-cortical brain circuits), and environmental factors.
How it is evaluated
Diagnosis is clinical, often using the Y-BOCS scale to gauge severity; a mandatory suicide-risk assessment is part of standard evaluation given the elevated risk in this population, per AAFP guidance.
Treatment
Exposure and response prevention (ERP, a form of CBT) and SSRIs are both first-line -- but OCD typically requires higher SSRI doses and a longer response window (8-12 weeks) than depression or other anxiety disorders before judging whether it's working.
When to seek care
Intrusive thoughts of harming yourself or others can be deeply distressing but are usually ego-dystonic (unwanted and distressing to the person, not reflective of true intent) -- still, any thoughts of suicide, or compulsions that become physically dangerous, warrant immediate crisis support.