Serotonin transporter gene promoter polymorphism and somatoform symptoms.
BACKGROUND
Symptoms of somatoform and affective disorders are thought to be connected to serotonergic neurotransmission because serotonin is known to regulate the functions relevant in these disorders, such as pain and mood. Previous studies have reported associations of these disorders with a functional polymorphism in the promoter region of the serotonin transporter gene, a limiting factor of the serotonergic neuronal system, as its alleles have been associated with differences in levels of synthesized transporter and therefore differences in reuptake efficiency.


METHODS
Ninety-one patients with at least 2 unexplained physical symptoms were clinically evaluated and genotyped for the triallelic genotypes of the serotonin transporter gene polymorphism; patients were recruited from 2001 until 2004. DSM-IV diagnoses were assessed using the International Checklists for ICD-10 and DSM-IV. Somatic complaints were quantified with an interview version of the Screening for Somatoform Symptoms, persistent symptoms in the last 2 years (SOMS-2) and the SOMS-7 (current symptoms in the last 7 days). Depressive symptoms were quantified with the Beck Depression Inventory (BDI).


RESULTS
Subjects with higher-expressing allele variants of the serotonin transporter gene (L'L' and L'S') had significantly more somatic symptoms in the last 2 years (trait) than those with lower-expressing variants (S'S') (P < .01). No differences could be found in regard to short-term somatic symptoms (ie, in the last 7 days). Neither depressive symptoms nor a comorbid diagnosis of major depression was associated with allelic variants.


CONCLUSIONS
Somatoform symptoms may be associated with a functional polymorphism in the promoter region of the serotonin transporter gene.
Hennings
Anika
A
Division of Clinical Psychology and Psychotherapy, Philipps University of Marburg, Gutenbergstrasse 18, 35032 Marburg, Germany. anika.hennings@staff.uni-marburg.de
Zill
Peter
P
Rief
Winfried
W
D057189:Checklist; D003865:Major Depressive Disorder / Q000235:genetics; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D015870:Gene Expression; D005787:Gene Frequency; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D038801:International Classification of Diseases; D008297:Male; D008875:Middle Aged; D010555:Personality Inventory; D011110:Polymorphism, Genetic / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011569:Psychiatric Status Rating Scales; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D013001:Somatoform Disorders / Q000175:diagnosis / Q000235:genetics*
C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins