What causes OCD?  

There are different theories about why OCD develops. None of these theories can fully explain every person’s experience, but researchers suggest that the following are likely to be involved in causing OCD: 

  • personal experience 
  • personality 
  • biological factors. 

Even though we don’t fully understand what causes OCD, it can still be successfully treated. You can read more about treatments here

Personal experience 

Some theories suggest that OCD is caused by personal experience. For example: 

  • If you’ve had a painful childhood experience, or suffered trauma, abuse or bullying, you might learn to use obsessions and compulsions to cope with anxiety. 
  • If your parents had similar anxieties and showed similar kinds of compulsive behaviour, you may have learned OCD behaviours as a coping technique. 
  • Ongoing anxiety or stress, or experiencing a stressful event like a car accident or starting a new job, could trigger OCD or make it worse. 
  • For some women, pregnancy or birth can trigger perinatal OCD. 


Some research suggests that people with certain personality traits may be more likely to have OCD. For example, if you are a neat, meticulous, methodical person with high standards, you may be more likely to develop OCD. 

Biological factors 

Some biological theories suggest that a lack of the brain chemical serotonin may have a role in OCD. However, it’s unclear whether this is the cause or an effect of the condition. 

Studies have also looked at genetic factors and how different parts of the brain might be involved in causing OCD, but have found nothing conclusive. 

Is childhood OCD caused by an infection? 

Some experts have noted that some children seem to develop OCD symptoms very suddenly after having a streptococcal (or strep) infection, such as strep throat or scarlet fever. However, no one knows why this can happen, and no research has yet been able to identify a physical cause to explain the link. Some children who develop OCD symptoms in this way show them for a while and then they fade. 

Previous page Next page