Obsessive Compulsive Disorder (OCD) is a mental illness defined by a person feeling the need to engage in routines repeatedly (called compulsions such as hand washing, closing doors several times) or having intrusive and repeated thoughts (called obsessions). People with OCD have difficulty controlling their thoughts and activities which leads to poor quality of life. Causes are unknown but some contributing factors include some genetic components and stress-inducing events such as child abuse.
Treatments include psychotherapy such as cognitive behavioural therapy and exposure therapy as well as medications such as antidepressants.