OCD can start at any time from preschool to adulthood.

Although OCD can occur at any age, there are generally two age ranges when OCD tends to first appear:

  • Between the ages 8 and 12.
  • Between the late teen years and early adulthood.

Although the exact cause of OCD is not fully understood, studies have shown that a combination of biological and environmental factors may be involved.


Twin and family studies have shown that people with first-degree relatives (such as a parent, sibling, or child) who have OCD are at a higher risk for developing OCD themselves. The risk is higher if the first-degree relative developed OCD as a child or teen.


Some research suggests that there are differences in the frontal cortex and subcortical structures of the brains of patients with OCD. Although the exact relationship between these brain differences and OCD symptoms are still unclear, it has been suggested that OCD involves problems in communication between the front part of the brain and deeper structures of the brain.


People who have experienced abuse (physical or sexual) in childhood or other stressful childhood events are at an increased risk for developing OCD.
Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections
Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcus (PANDAS) is the sudden, rapid-onset of obsessive compulsive behavior, as well as possible movement and behavioral symptoms, following a Streptococcus pyogenes (“Strep”) infection. The condition is thought to be the result of the child’s immune system mistakenly attacking an area of the brain, the basal ganglia, rather than the Strep infection.