Obsessive-compulsive disorder and serotonin: is there a connection?

Area of Science:

• Neuroscience
• Psychiatry
• Pharmacology

Background:

• Clomipramine's effectiveness in treating obsessive-compulsive disorder (OCD) suggests a role for serotonin.
• The

Purpose of the Study:

• To investigate the serotonin hypothesis of OCD.
• To evaluate the role of serotonin reuptake inhibition in clomipramine's antiobsessional effects.

Main Methods:

• Assessed serotonergic function in 16 OCD outpatients and controls.
• Compared zimelidine (serotonin reuptake inhibitor) with desipramine (noradrenergic reuptake inhibitor).

Main Results:

• No significant differences in platelet serotonin uptake between OCD patients and controls.
• Increased cerebrospinal fluid 5-hydroxyindoleacetic acid (5-HIAA) in OCD patients may indicate higher brain serotonin turnover.
• Zimelidine did not show clinical effectiveness, while desipramine had weak effects.
• Patients unresponsive to zimelidine or desipramine improved with clomipramine.

Conclusions:

• Pharmacological blockade of serotonin reuptake alone is insufficient for antiobsessional response in OCD.
• The findings challenge the sole reliance on serotonin reuptake inhibition as the mechanism for clomipramine's efficacy in OCD.