The putative catalytic role of higher serotonin bioavailability in the clinical response to exposure and response prevention in obsessive-compulsive disorder

Abstract

Objective: Exposure and response prevention (ERP) is effective to treat obsessive-compulsive disorder (OCD), but the lack of tolerance to the aversion nature of exposure techniques results in a high drop-out rate. There have been reports of a generic stress endurance effect of serotonin (5-HT) in the central nervous system (CNS) which might be explained by suppression of defensive fixed action patterns. Previous studies have proposed that higher baseline 5-HT concentration and slow decrease in concentration during drug treatment of OCD were predictors of good clinical response to 5-HT reuptake inhibitors. The objective of this study was to investigate whether pre-treatment platelet rich plasma (PRP) 5-HT concentration is associated with latency of treatment response and final response to an ERP protocol for obsessive-compulsive disorder (OCD). Methods: Thirty adult and treatment-free OCD patients were included in an 8-week, 16-session ERP protocol. 5-HT concentration was determined at baseline and after treatment. Patients with a reduction X30% on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) at the end of ERP were defined as responders. Results: A positive correlation between baseline 5-HT concentration and reduction of symptoms on the Y-BOCS was observed after 4 weeks. Baseline 5-HT concentration was not correlated with clinical response after 8 weeks of ERP, possibly due to the similar though delayed clinical response of patients with lower (compared to those with higher) baseline 5-HT concentration. Patients with higher 5-HT baseline concentration also showed more improvement in depressive symptoms with treatment. Conclusion:The present results partially support the hypothesis of a stress endurance effect of 5-HT in OCD patients. According to the literature, fast onset responders possibly have more or larger 5-HT containing neurons, higher endogenous 5-HT synthesis or lower monoamine oxidase activity; all these hypotheses remain to be investigated.

Concomitant treatment with sertraline and social skills training improves social skills acquisition in social anxiety disorder: A double-blind, randomized controlled trial

“…This conclusion is consistent with the accepted practice that exposure therapy is an essential component of treatment for phobic avoidance disorders [ 13 ]. Therefore, experiencing and mastering aversion during exposure procedures is, putatively, a core element of CBT effectiveness [ 14 ].…”

Monoamine abnormalities in the SAPAP3 knockout model of obsessive-compulsive disorder-related behaviour

“…However, many inconsistencies have made it difficult to isolate specific abnormalities within the serotonergic system. For example, OCD patients and healthy controls show similar levels of plasma serotonin and cerebrospinal serotonin and metabolites [29][30][31], but recent work indicates that plasma serotonin concentration is positively correlated with OCD symptom reduction [30]. In addition, agonists can reduce or exacerbate OCD symptoms depending on the drug's receptor subtype affinity [28,31].…”