Treatment of obsessive-compulsive spectrum disorders with SSRIs

Obsessive-compulsive spectrum disorders (OCSDs) are now recognised as distinct diagnostic entities related to obsessive-compulsive disorder (OCD). The features of OCSDs and OCD overlap in many respects including demographics, repetitive intrusive thoughts or behaviours, comorbidity, aetiology and preferential response to anti-obsessional drugs such as the selective serotonin reuptake inhibitors (SSRIs).

Literature was reviewed and preliminary data from various studies were re-examined to assess the relationship between compulsivity and impulsivity, and between OCD and OCSDs.

OCSDs include both compulsive and impulsive disorders and these can be viewed as lying at opposite ends of the dimension of risk avoidance. Compulsiveness is associated with increased frontal lobe activity and increased serotonergic activity, while impulsiveness is associated with reduced activity of these variables. Neural circuits affected by serotonergic pathways have been identified and pharmacological challenge of OCSD patients with serotonin receptor agonists have supported the involvement of serotonergic processes.

SSRIs such as fluvoxamine have established efficacy in OCD and preliminary studies indicate that they are also effective in OCSDs. The features of three specimen OCSDs--body dysmorphic disorder, pathological gambling and autism--and their treatment with SSRIs are reviewed.