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

• Published in: Biological psychiatry (1969) Vol. 57; no. 4; pp. 319 - 327
• Main Authors: Pizzagalli, Diego A., Jahn, Allison L., O’Shea, James P.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 15.02.2005; Elsevier Science
• Subjects: Adolescent; Adult; Adult and adolescent clinical studies; Affective Symptoms - diagnosis; Affective Symptoms - psychology; Analysis of Variance; anhedonia; appetitive behavior; Bias; Biological and medical sciences; Character; Depression; Depressive Disorder - diagnosis; Depressive Disorder - psychology; Expressed Emotion - physiology; Female; Humans; Male; Medical sciences; Mood disorders; Motivation; Personality Inventory; Phenotype; Probability; Psychiatric Status Rating Scales; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Reaction Time; Reinforcement Schedule; Reinforcement, Psychology; reinforcers; reward bias; Statistics as Topic; phenotype; Depression; reinforcers; appetitive behavior; reward bias; anhedonia; Mood disorder; Human; Phenotype; Pleasure unpleasure; Anhedonia; Reward; Signal detection
• ISSN: 0006-3223; 1873-2402
• DOI: 10.1016/j.biopsych.2004.11.026

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. 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. 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. 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.