More than 30 percent of adults with Obsessive Compulsive Disorder (OCD) have severe symptoms of obsession or compulsions since early childhood (early onset of ocd). Very often the diagnosis is missed because nobody thinks about the possibility of this neurobiological disorder.

It is important to consider other neurobiological disorders related to ocd, esp. ADHD and conduct disorder, trichotillomania or Tourette syndrome. Very often a spectrum of comorbid disorders (including other disorders like body dysmorphic disorders) can be found. Secondary affective problems (depressive disorders) or anxiety problems (very often social phobia) and alcohol selfmedication can cause severe problems.

A small group of children and adolescents with OCD symptoms may have a so called PANDAS syndrome, obsessive-compulsive symptoms caused by an infection with streptococci.