OCD: Serotonergic mechanisms

Jennifer I. Lissemore, Marco Leyton, Paul Gravel, Debbie Sookman, Thomas E Nordahl, Chawki Benkelfat

Research output: Chapter in Book/Report/Conference proceedingChapter

1 Scopus citations


Obsessive-compulsive disorder (OCD) is typically treated with selective serotonin- reuptake inhibitors (SSRIs), cognitive behavioral therapy (CBT), or both. The neurobiological effects of these treatments that are associated with symptom improvement, however, remain unclear. The neurotransmitter serotonin has been implicated in OCD pathology, including in brain circuits contained in corticostriato- thalamic loops; yet, there is no consensus in the literature over a particular underlying serotonergic mechanism in OCD. Recent studies have used the α-[ 11C]methyl-L-tryptophan tracer coupled with positron emission tomography (PET) to estimate brain regional serotonin synthesis capacity in OCD patients in vivo. Regions that exhibited elevated serotonin synthesis in symptomatic OCD, relative to healthy controls, demonstrated a paradoxical and further increase during treatment with CBT or SSRI, parallel to symptomatic improvement. This suggests that serotonin engagement may be an attempt at inhibiting symptoms at baseline, albeit unsuccessfully, and that “braking” or “resistance” might gradually become more effective, and eventually successful, with the help of adapted behavioral interventions and/or SSRIs.

Original languageEnglish (US)
Title of host publicationPET and SPECT in Psychiatry
PublisherSpringer Berlin Heidelberg
Number of pages18
ISBN (Electronic)9783642403842
ISBN (Print)9783642403835
StatePublished - Jan 1 2014

ASJC Scopus subject areas

  • Medicine(all)


Dive into the research topics of 'OCD: Serotonergic mechanisms'. Together they form a unique fingerprint.

Cite this