Brain serotonin synthesis capacity in obsessive-compulsive disorder: effects of cognitive behavioral therapy and sertraline

• Published in: Translational psychiatry Vol. 8; no. 1; pp. 82 - 10
• Main Authors: Lissemore, Jennifer I., Sookman, Debbie, Gravel, Paul, Berney, Alexandre, Barsoum, Amir, Diksic, Mirko, Nordahl, Thomas E., Pinard, Gilbert, Sibon, Igor, Cottraux, Jean, Leyton, Marco, Benkelfat, Chawki
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 18-04-2018; Nature Publishing Group
• Subjects: 59/57; 59/78; 631/378; 692/699/476; Adult; Antidepressants; Behavior modification; Behavioral Sciences; Biological Psychology; Brain - diagnostic imaging; Brain - metabolism; Cognitive Behavioral Therapy; Combined Modality Therapy; Female; Humans; Male; Medicine; Medicine & Public Health; Middle Aged; Neurosciences; Neuroses; Obsessive compulsive disorder; Obsessive-Compulsive Disorder - diagnostic imaging; Obsessive-Compulsive Disorder - drug therapy; Obsessive-Compulsive Disorder - metabolism; Pharmacotherapy; Positron-Emission Tomography; Psychiatry; Serotonin; Serotonin - biosynthesis; Serotonin Uptake Inhibitors - therapeutic use; Sertraline - therapeutic use; Treatment Outcome; Young Adult
• ISSN: 2158-3188; 2158-3188
• DOI: 10.1038/s41398-018-0128-4

Cognitive behavioral therapy (CBT) and selective serotonin reuptake inhibitors (SSRIs) are both effective treatments for some patients with obsessive-compulsive disorder (OCD), yet little is known about the neurochemical changes related to these treatment modalities. Here, we used positron emission tomography and the α-[
11
C]methyl-
l
-tryptophan tracer to examine the changes in brain regional serotonin synthesis capacity in OCD patients following treatment with CBT or SSRI treatment. Sixteen medication-free OCD patients were randomly assigned to 12 weeks of either CBT or sertraline treatment. Pre-to-post treatment changes in the α-[
11
C]methyl-
l
-tryptophan brain trapping constant,
K
* (ml/g/min), were assessed as a function of symptom response, and correlations with symptom improvement were examined. Responders/partial responders to treatment did not show significant changes in relative regional tracer uptake; rather, in responders/partial responders, 12 weeks of treatment led to serotonin synthesis capacity increases that were brain-wide. Irrespective of treatment modality, baseline serotonin synthesis capacity in the raphe nuclei correlated positively with clinical improvement. These observations suggest that, for some patients, successful remediation of OCD symptoms might be associated with greater serotonergic tone.