Psychobiological aspects of somatoform disorders: contributions of monoaminergic transmitter systems.
OBJECTIVE
To evaluate the possible biological aspects of 'unexplained physical symptoms', this study examined serotonergic and noradrenergic monoamino acids in somatoform disorders and/or depression.


METHODS
Blood samples of 150 subjects from 4 groups (somatization syndrome; depression; depression and somatization; controls) were analyzed for amino acids contributing to the serotonergic and noradrenergic system and peripheral muscle energy balance (tryptophan, valine, leucine, isoleucine, phenylalanine and tyrosine).


RESULTS
Tryptophan, branched chain amino acids and other serotonergic amino acids were decreased in patients with somatoform symptoms, even when no depression was present.


CONCLUSIONS
We conclude that serotonergic amino acids are biological correlates of multiple unexplained symptoms. Ways of action do not only involve brain mechanisms, but also energy metabolism in peripheral muscles.
Rief
Winfried
W
Center for Behavioral Medicine, Klinik Roseneck, Prien am Chiemsee, Germany. rief@mailer.uni-marburg.de
Pilger
Florian
F
Ihle
Daniel
D
Verkerk
Robert
R
Scharpe
Simon
S
Maes
Michael
M
D000328:Adult; D000597:Amino Acids, Branched-Chain / Q000097:blood; D000704:Analysis of Variance; D015306:Biogenic Monoamines / Q000097:blood*; D016022:Case-Control Studies; D003863:Depression / Q000097:blood / Q000150:complications; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D007406:Interview, Psychological; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D010649:Phenylalanine / Q000097:blood; D013001:Somatoform Disorders / Q000097:blood* / Q000150:complications; D014364:Tryptophan / Q000097:blood
D000597:Amino Acids, Branched-Chain; D015306:Biogenic Monoamines; D010649:Phenylalanine; D014364:Tryptophan