Related Experiment Video
Updated: Aug 19, 2026

An Unpredictable Chronic Mild Stress Protocol for Instigating Depressive Symptoms, Behavioral Changes and Negative Health Outcomes in Rodents
Published on: December 2, 2015
[Analysis of precipitating factors in a sample of patients hospitalized for endogenous depression]
Abstract:
The purpose of this paper has been to assess the relationship between depression and a number of current areas of social and somatic stress. The sample consisted of 143 consecutive depressed in patients. Our findings indicate that precipitating events were present in 41.2% of the overall depressive episodes. Late onset patients had more events than early onset probands. The number of precipitating factors was higher in the first depressive episode and relapses seemed to occur more independently from unfavourable environmental conditions. The presence of such events however had no relationship to sex, age and social class.
Related Concept Videos
Depression: Overview
Depressive Disorders: MDD and Dysthymia
Psychological and Sociocultural Causes of Schizophrenia
Depressive Disorders: Etiology
Biological Factors in Depression
Biological predispositions significantly influence the risk of developing depressive disorders. Genetic studies highlight the role of variations in the serotonin transporter...

