Nutritional up-regulation of serotonin paradoxically induces compulsive behavior

Nutr Neurosci. 2010 Dec;13(6):256-64. doi: 10.1179/147683010X12611460764688.


Dietary etiologies or treatments for complex mental disorder are highly controversial in psychiatry. Nevertheless, diet affects brain chemistry (particularly serotonin), and can reduce abnormal behavior in humans and animals. We formulated a diet that elevated brain serotonin and tested whether it would reduce hair pulling in a mouse model of trichotillomania. In a double-blind crossover trial, dietary elevation of brain serotonin unexpectedly increased hair pulling (P = 0.0006) and induced ulcerative dermatitis (UD; P = 0.001). The causative agent for UD is unknown. Therefore, we fed the treatment diet to a second group of mice to test whether UD is behavioral in origin. The diet increased scratching behavior (P < 0.0001). However, high scratching behavior (P = 0.027) and low barbering (P = 0.040) prior to treatment predicted the development of UD. Thus diet can trigger the onset of a complex disorder in the absence of an underlying metabolic deficit. Furthermore, we propose UD as model of compulsive skin-picking.

MeSH terms

  • Animals
  • Brain Chemistry
  • Dermatitis / etiology
  • Diet*
  • Dietary Carbohydrates / administration & dosage
  • Dietary Proteins / administration & dosage
  • Disruptive, Impulse Control, and Conduct Disorders / drug therapy
  • Disruptive, Impulse Control, and Conduct Disorders / etiology*
  • Female
  • Grooming / physiology
  • Hydroxyindoleacetic Acid / analysis
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Selective Serotonin Reuptake Inhibitors / therapeutic use
  • Serotonin / analysis*
  • Serotonin / physiology*
  • Skin Ulcer / etiology
  • Trichotillomania / etiology
  • Tryptophan / administration & dosage
  • Weight Gain


  • Dietary Carbohydrates
  • Dietary Proteins
  • Serotonin Uptake Inhibitors
  • Serotonin
  • Hydroxyindoleacetic Acid
  • Tryptophan