Obsessive-compulsive disorder is a common, chronic mental disorder in which a person has uncontrollable, recurring thoughts (‘obsessions’) and/or behaviours (‘compulsions’) that they feel the need to repeat over and over.

Obsessions are repeated thoughts, feelings or mental images that trigger anxiety. Compulsions are repetitive behaviours that people feel the urge to do in response to their obsessive thoughts.

These obsessions and compulsions can take over a person’s life, affecting every aspect from school, work and relationships to day-to-day activities. While OCD can come and go or reduce over time, if left untreated it can lead to other problems like substance abuse in an attempt to gain control over unwelcome thoughts and urges.

OCD affect people of all ages and backgrounds, and typically shows up earlier in boys than in girls.

OCD can be difficult to diagnose, since everyone goes through periods where their thoughts are set on a particular thing and they may display behaviours that indicate doubt. It is diagnosed using a detailed psychological evaluation that takes into account thoughts, feelings, signs and symptoms, and behaviour patterns.


The exact causes of OCD are still unknown, but risk factors include:

Genetics. People with a first-degree relative (e.g., a parent, sibling or child) with OCD are at higher risk of also developing OCD, and at even more risk of the first-degree relative developed OCD in childhood or adolescence.

Brain structure and function. Imaging studies have indicated a relationship between certain brain structure types and OCD, but how exactly this works is still unclear.

Environment. There is an association between traumatic or extremely stressful experiences in childhood and OCD, and some children begin to show signs of OCD following a streptococcal infection.

Signs & Indications

People with OCD generally struggle to control their thoughts and behaviour, even though they may be aware that those thoughts and behaviours are excessive. They get no pleasure from the repetitive behaviour, though they might get some respite from their obsessive thoughts when performing those behaviours.

Everyone double-checks things occasionally, and everyone has moments of doubt. Not all such thoughts are obsessions and not all such actions are compulsions. Here are some of the signs of OCD:

Obsessions Compulsions
  • Fear of germs or contamination
  • Aggressive and angry thoughts towards others or oneself
  • Wanting things to be arranged ‘perfectly’
  • Excessive cleaning or hand washing
  • Arranging and rearranging things in a particular way
  • Repeatedly checking on things one has already checked before
  • Compulsively counting

Some people with OCD also experience motor tics: sudden, brief, repetitive movements such as blinking or other eye movement, shrugging or jerking shoulders, clearing one’s throat repeatedly, sniffing or grunting.


OCD is typically treated with a combination of psychotherapy and medication personalised to each individual’s needs. Most people respond well to treatment, though some may continue to experience mild signs of OCD for a while.

To effectively treat OCD, it is important to take other mental disorders into consideration when deciding on the course of treatment.

Therapy is effective on both adults and children, and can sometimes be as effective as medication. Cognitive behavioural therapy (CBT) helps to put one’s thoughts and behaviours in perspective so they can be better managed and overcome.