title: Psychobiological aspects of somatoform disorders: contributions of monoaminergic transmitter systems.
abstract: 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.
authors.affiliation: Center for Behavioral Medicine, Klinik Roseneck, Prien am Chiemsee, Germany. rief@mailer.uni-marburg.de
authors.forename: Winfried
authors.initials: W
authors.lastname: Rief
authors.forename: Florian
authors.initials: F
authors.lastname: Pilger
authors.forename: Daniel
authors.initials: D
authors.lastname: Ihle
authors.forename: Robert
authors.initials: R
authors.lastname: Verkerk
authors.forename: Simon
authors.initials: S
authors.lastname: Scharpe
authors.forename: Michael
authors.initials: M
authors.lastname: Maes
mesh_terms: 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
chemical_list: D000597:Amino Acids, Branched-Chain; D015306:Biogenic Monoamines; D010649:Phenylalanine; D014364:Tryptophan