Reduced availability of serotonin transporters in obsessive-compulsive disorder correlates with symptom severity - a [11C]DASB PET study.
Reimold M,
Smolka MN,
Zimmer A,
Batra A,
Knobel A,
Solbach C,
Mundt A,
Smoltczyk HU,
Goldman D,
Mann K,
Reischl G,
Machulla HJ,
Bares R,
Heinz A.
Department of Nuclear Medicine, University of Tübingen, Tübingen, Germany.
Reduced availability of brainstem serotonin transporters (5-HTT) has been observed in vivo in obsessive-compulsive disorder (OCD). However, results vary and may be influenced by competition with endogenous serotonin. Using positron emission tomography (PET) and [11C]DASB, a specific 5-HTT ligand that showed no competition with serotonin for 5-HTT binding in vitro, we tested the hypothesis that 5-HTT availability is reduced in OCD patients and correlated with OCD severity. METHODS. 5-HTT availability in the thalamus and the midbrain was measured in nine drug-free OCD patients and compared with 19 healthy controls, matched for the individual combination of 5-HTT genotype, gender and smoking status. OCD severity was assessed with the Yale-Brown obsessive compulsive scale (Y-BOCS). RESULTS. 5-HTT availability was significantly reduced in the thalamus and midbrain of OCD patients. Age and 5-HTT in the thalamus explained 83% of OCD severity in patients that were drug-free for at least 1 year. CONCLUSION. This PET study confirms a central role of the serotonergic system, particularly the thalamus in the pathogenesis of obsessive compulsive disorder.
PMID: 17713719 [PubMed - indexed for MEDLINE]