UNIT 5.9 Models of Affective Illness: Chronic Mild Stress in the Rat

  1. Mariusz Papp

Published Online: 1 JUN 2012

DOI: 10.1002/0471141755.ph0509s57

Current Protocols in Pharmacology

Current Protocols in Pharmacology

How to Cite

Papp, M. 2012. Models of Affective Illness: Chronic Mild Stress in the Rat. Current Protocols in Pharmacology. 57:5.9:5.9.1–5.9.11.

Author Information

  1. Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland

Publication History

  1. Published Online: 1 JUN 2012
  2. Published Print: JUN 2012


Described in this unit is a chronic mild stress (CMS) procedure used for predicting an antidepressant response. Following exposure to a variety of mild stressors for a period of several weeks, rat behavior is modified in a number of ways. Among these is a substantial reduction in consumption of a 1% sucrose solution. Chronic administration of antidepressant drugs reverses diminished enthusiasm for sucrose in these subjects. While most antidepressants must be administered for at least 3 to 5 weeks to normalize behavior, there are treatments that display a more rapid onset of action. More recently, it has been shown that the CMS-induced deficit in sucrose consumption can also be reversed by second-generation antipsychotics. Based on these findings, the CMS model can be employed in discovery programs aimed at identifying antianhedonic drugs (e.g., antidepressants and antipsychotics) that act more quickly than existing agents. Curr. Protoc. Pharmacol. 57:5.9.1-5.9.11. © 2012 by John Wiley & Sons, Inc.


  • chronic stress;
  • animal model;
  • depression;
  • anhedonia;
  • antidepressants