Public Release: 

A genetic contribution to obsessive compulsive disorder

Molecular Psychiatry

ARTICLE: 5HT1Db receptor gene implicated in the pathogenesis of Obsessive-Compulsive Disorder: further evidence from a family-based association study.

AUTHORS: E Mundo, MA Richter, G Zai, F Sam , J McBride, F Macciardi and JL Kennedy

Neurogenetics Section and Anxiety Disorders Clinic, Centre for Addiction and Mental Health, Department of Psychiatry, University of Toronto, Toronto (ON), Canada.

Obsessive-Compulsive Disorder (OCD) is a severe psychiatric condition affecting up to 3% of the general population lifetime. It is characterized by intrusive unwanted thoughts (obsessions) and the need to perform repetitive acts or rituals in order to alleviate the anxiety (compulsions). As an example, a patient who fears contamination would be afraid of touching anything and would feel that they must wash their hands over and over.

The causes of OCD remain obscure. However, there is strong evidence for a genetic component (the risk of developing OCD is higher in the relatives of affected), and for the involvement of the serotonin (5HT) neurochemical system. Serotonin is a neurotransmitter that is essential for communication between cells, and it is possible that the receptors that tell how much serotonin should be released may be altered in OCD patients.

The researchers studied the DNA sequence of the gene for one of the receptors of the 5HT system (the 5HT1Dbeta) that regulates 5HT release. They studied families with at least one subject affected by OCD. The genetic make up of the parents was compared to that of the patients to determine if DNA is a reason for OCD. The parents of patients were found to pass on more often one of the variants of the 5HT1Dbeta receptor gene to their affected offspring.

This shows that a person who inherits that variant of the gene has an increased chance of developing OCD.

The study findings, published in the September issue of Molecular Psychiatry, are clear-cut and are set to turn future genetic studies of OCD towards the serotonin neurochemical system. This should allow greater understanding of the biological mechanisms behind the development of this devastating illness. Scientists are optimistic that the research will allow earlier identification and treatment of those who are vulnerable to developing OCD, and will also encourage the design and use of new treatments to redice symptoms of the illness.

Citation source: Molecular Psychiatry 2002 Volume 7, number 7, pages 805-809.


For further information on this work, please contact Dr. James L. Kennedy, Head, Neurogenetics Section R-31, Centre for Addiction and Mental Health, Clarke Site, 250 College Street, Toronto, ON M5T 1R8, Canada; phone: +1 416-979-4987; FAX: +1 416-979-4666; e-mail:

Molecular Psychiatry is published by the Nature Publishing Group.

Editor: Julio Licinio, M.D.; phone: +1 310 825-7113; FAX: +1 310 206-6715; e-mail:

For a copy of this article, please contact Frank Sissingh, editorial assistant, e-mail:


Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.