N-methyl Glycine (Sarcosine) for the Treatment of Obsessive Compulsive Disorder (OCD)

Sarcosine as Primary or Adjunctive Therapy in Obsessive Compulsive Disorder: A Prospective, Open-label Study

Several lines of evidence implicate glutamatergic dysfunction in the pathophysiology of obsessive compulsive disorder (OCD). Sarcosine, also known as N-methylglycine, is an endogenous antagonist of glycine transporter-I (GlyT-I), which potentiates glycine's action at the glycine site of N-methyl-D-aspartate (NMDA) receptors. In this 10-week open-label trial, we examined the efficacy and safety of sarcosine treatment in OCD patients.

Inclusion Criteria:

• a primary OCD according to DSM-IV
• at least 1 year's duration of OC symptoms and a minimum severity score of ≥16 on Yale-Brown Obsessive Compulsive Scale
• drug naïve at study entry or
• being free from psychotropic medication for at least 8 weeks at study entry,or
• inadequately responded to ongoing psychotropic medications at study entry (defined by a Y-BOCS score of ≧16 despite treatment with maximum tolerated dose of a SRI medication for at least 8 weeks)

Exclusion Criteria:

• patients with moderate to severe depression defined by a 21-item Hamilton Depression Rating Scale score of >17,
• a history of bipolar disorder, schizophrenia, schizoaffective disorder, or other psychosis as defined by DSM-IV, or if they were at significant risk of suicide, and
• with clinically significant organic disease including cardiovascular, hepatic, pulmonary, neurologic, metabolic, or renal disease