Neuropsychiatric explanations

It is proven that OCD primarily involves the brain regions of the striatum and the cingulate cortex. It involves several different receptors, mostly H2, M4, nk1, NMDA, and non-NMDA glutamate receptors. Those correlations are as follows:

Activity positively correlated to severity:

• H2
• M4
• nk1
• non-NMDA glutamate receptors

 
Activity negatively correlated to severity:

• NMDA
• mu opioid
• 5-HT1D
• 5-HT2C

Differential diagnosis

People with OCD may be diagnosed with other conditions, such as Tourette syndrome, compulsive skin picking, body dysmorphic disorder and trichotillomania but the differentiating between obsessive-compulsive disorder and a depressive disorder may be the most difficult. This is because these two types of symptoms so frequently occur together. Although obsessional thoughts and compulsive acts commonly coexist in several other conditions, it is useful to be able to specify the characteristic set of symptoms as predominant, since they may respond to different treatments.

OCD, depression and drug abuse

There are some researches which tried to demonstrate a link between drug addiction and obsessive compulsive disorder. They proved that there is a higher risk of drug addiction among those with any type of anxiety disorder. Anyway, experts still don’t know whether the drug addiction among OCD patients may serve as a type of compulsive behavior or just as a coping mechanism.
Depression is also extremely prevalent among sufferers of OCD. People with OCD may feel depressed because of the fact that they get out of control.

OCD and other disorders

Disorders that frequently occur with OCD include:
 

• other anxiety disorders,
• depression,
• disruptive behavior disorders
• attention deficit hyperactivity disorder,
• learning disorders,
• trichotillomania
• habit disorders such as nail biting or skin picking