Does physical anhedonia play a role in depression? A 20-year longitudinal study.
BACKGROUND
Anhedonia towards physical or sensory experiences (i.e., physical anhedonia) has most often been examined as a differentia of schizophrenia and not depression, despite the fact that general anhedonia is a core feature of many models of Major Depressive Disorder (MDD).


METHODS
Forty-nine participants with non-psychotic MDD were recruited from inpatient settings and followed-up six times over 20 years. The three aims of the study was to assess a) the stability of physical anhedonia over time, b) whether physical anhedonia relates to the course of depressive symptoms over time, and c) whether physical anhedonia relates to three domains of functioning - work, social functioning, or re-hospitalizations.


RESULTS
We found that over time physical anhedonia was relatively stable and related to depressive symptoms (both between and within person). Physical anhedonia was also related to certain aspects of functioning, though less robustly than depressive symptoms.


CONCLUSIONS
Because depressive symptoms, functioning, and physical anhedonia were measured concurrently at each follow-up, the direction of causality among these variables could not be assessed. Additionally, because our sample was recruited from inpatient settings, our findings may not generalize to individuals with less severe depression.


CONCLUSIONS
A trait tendency to experience decreased pleasure to positive physical stimuli is a clinically meaningful variable for those with MDD and may be a behavioral endophenotype for a more severe form of depression.
Shankman
Stewart A
SA
University of Illinois, Chicago, IL, USA. stewarts@uic.edu
Nelson
Brady D
BD
Harrow
Martin
M
Faull
Robert
R
D003865:Major Depressive Disorder / Q000453:epidemiology* / Q000523:psychology* / Q000534:rehabilitation; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D010641:Phenotype; D015995:Prevalence; D012720:Severity of Illness Index; D012919:Social Behavior; D013997:Time Factors; D055815:Young Adult