Toward an objective characterization of an anhedonic phenotype: a signal-detection approach

Biol Psychiatry. 2005 Feb 15;57(4):319-27. doi: 10.1016/j.biopsych.2004.11.026.


Background: Difficulties in defining and characterizing phenotypes has hindered progress in psychiatric genetics and clinical neuroscience. Decreased approach-related behavior and anhedonia (lack of responsiveness to pleasure) are considered cardinal features of depression, but few studies have used laboratory-based measures to objectively characterize these constructs.

Methods: To assess hedonic capacity in relation to depressive, particularly anhedonic, symptoms, 62 participants completed a signal-detection task based on a differential reinforcement schedule. Anhedonia was operationalized as decreased reward responsiveness.

Results: Unequal frequency of reward between two correct responses produced a response bias (i.e., a systematic preference to identify the stimulus paired with the more frequent reward). Subjects with elevated depressive symptoms (Beck Depression Inventory scores >/= 16) failed to show a response bias. Impaired reward responsiveness predicted higher anhedonic symptoms 1 month later, after controlling for general negative affectivity.

Conclusions: Impaired tendency to modulate behavior as a function of prior reinforcement might underline diminished hedonic capacity in depression. When applied to a clinical population, objective assessments of participants' propensity to modulate behavior as a function of reward might provide a powerful tool for improving the phenotypic definition of depression and thus offer a reliable behavioral screening approach for neuroscience studies of depression.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Affective Symptoms / diagnosis
  • Affective Symptoms / psychology*
  • Analysis of Variance
  • Bias
  • Character
  • Depressive Disorder / diagnosis
  • Depressive Disorder / psychology*
  • Expressed Emotion / physiology
  • Female
  • Humans
  • Male
  • Motivation*
  • Personality Inventory
  • Phenotype*
  • Probability
  • Psychiatric Status Rating Scales
  • Reaction Time
  • Reinforcement Schedule
  • Reinforcement, Psychology
  • Statistics as Topic