title: Alterations of niacin skin sensitivity in recurrent unipolar depressive disorder.
abstract: BACKGROUND
  Skin flushing after niacin (methylnicotinate, vitamin B(3)) stimulation is a biological marker of availability of polyunsaturated fatty acids (PUFA). Decreased PUFA levels have been reported in depressive disorder, while add-on supplementation of omega-3 PUFA has been suggested to improve depressive symptoms. This study aimed to clarify whether a disturbance of niacin skin flushing occurs also in depression, and to identify patient characteristics for those who might benefit from PUFA supplementation.
  
  
  METHODS
  We studied 30 patients with recurrent unipolar depressive disorder during a major depressive episode (treated with antidepressants), and 30 healthy volunteers matched for age and gender. Aqueous methylnicotinate was applied in three dilution steps (0.001M, 0.01M, and 0.1M) onto the inner forearm skin. Skin flushing was assessed in three-minute intervals over 15min using optical reflection spectroscopy.
  
  
  RESULTS
  While there was no overall difference in skin flushing between patients and controls, niacin sensitivity was inversely correlated with severity of symptoms, and flush deficits were significantly associated with depressed mood, feelings of anxiety and somatic symptoms (loss of appetite and weight loss).
  
  
  CONCLUSIONS
  Results are suggestive of a subgroup of depressive patients characterised by a specific symptom cluster and disturbed niacin skin flushing.
authors.affiliation: Department of Psychiatry, University of Jena, Philosophenweg 3, D-07740 Jena, Germany. stefan.smesny@med.uni-jena.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Smesny
authors.forename: Kati
authors.initials: K
authors.lastname: Baur
authors.forename: Nicole
authors.initials: N
authors.lastname: Rudolph
authors.forename: Igor
authors.initials: I
authors.lastname: Nenadic
authors.forename: Heinrich
authors.initials: H
authors.lastname: Sauer
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D003866:Depressive Disorder / Q000097:blood* / Q000175:diagnosis* / Q000523:psychology; D003865:Major Depressive Disorder / Q000097:blood* / Q000175:diagnosis* / Q000523:psychology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005231:Fatty Acids, Unsaturated / Q000097:blood*; D005260:Female; D005483:Flushing / Q000097:blood / Q000139:chemically induced*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009525:Niacin; D010328:Patch Tests; D010555:Personality Inventory / Q000706:statistics & numerical data; D011594:Psychometrics; D011599:Psychopathology; D012008:Recurrence; D055815:Young Adult
chemical_list: D015415:Biomarkers; D005231:Fatty Acids, Unsaturated; D009525:Niacin