In-vivo serotonin transporter availability and somatization in healthy subjects

Dysregulation of the central serotonergic system is implicated in somatization, which can lead to manifest mental disease. However, neuroimaging studies on serotonin transporter (SERT) availability and somatoform symptoms as assessed by the Symptom Checklist 90 Revised (SCL-90-R) are sparse and reveal inconsistent results. The aim of this study was to explore for the first time the relationship between SERT and somatoform symptom expression in healthy volunteers including the analysis of the SERT-LPR genotype. Fourteen healthy subjects (age 36.07 ± 7.22 years, 9 females) completed the SCL-90-R, underwent [11C]DASB PET and were genotyped on the same day. SERT binding potentials (BPND) were quantified with the multilinear reference tissue model (MRI coregistration). The BPND of the right orbitofrontal cortex (OFC) correlated positively with the somatization subscale. The SERT availability of the right OFC correlated significantly with the obsessive–compulsive subscale and the degree of anxiety was associated with the BPND of the right hippocampus. No main genotype effect on regional SERT availability or on the association between SERT BPND and the respective SCL-90-R subscales was observed. Our findings document a positive correlation between frontal SERT availability and the severity of somatoform symptoms prior to the onset of disease