Related Experiment Video
Updated: Oct 9, 2026

An Unpredictable Chronic Mild Stress Protocol for Instigating Depressive Symptoms, Behavioral Changes and Negative Health Outcomes in Rodents
Published on: December 2, 2015
Increased prevalence of negative life events in subtypes of major depressive disorder
1Department of Psychiatry, Hadassah-Hebrew University Medical Center, Herzog Hospital, Jerusalem, Israel.
Abstract:
The prevalence of negative life events is known to be increased among patients with depression. Little data exist on the specific subtypes of depression that are related to negative life events. Our study aimed to address this issue. We compare 115 patients with major depressive disorder (MDD) to 60 normal controls. MDD patients reported experiencing one (P = .0001) or two (P = .01) negative life events more frequently than controls. Patients reported marital, other personal problems, and medical events significantly more often than controls (P < .01). Patients did not report more positive life events, and did not attribute greater severity to their adversities than controls. Younger MDD patients experienced four (P = .01) negative life events significantly more often than older patients. Similarly, patients with mild-moderate depression, nonmelancholic depression, or first episode of depression (FDE), respectively, experienced three or four life events significantly more often than patients with severe, melancholic, or recurrent depression (RDE). Other patient and illness characteristics such as gender, early parental loss, family history of depression or other mental disorders, psychotic features, suicide attempts, and chronicity were not related to increased prevalence of negative life events. Our results support the hypothesis that a subset of patients with MDD is especially prone to suffer from a cluster of negative life events. This subgroup is at increased risk for relapse and poor prognosis. The implications of these results for further research and for treatment are discussed.
Related Concept Videos
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...
Depressive Disorders: MDD and Dysthymia
Stress and Mental Health
Individuals with depression often experience challenges in both their personal and professional...
Negative and Cognitive Symptoms of Schizophrenia
Negative Symptoms
Negative symptoms of schizophrenia manifest as deficits in normal emotional and behavioral functioning, profoundly impacting daily life. Individuals with schizophrenia often display a flat affect, characterized by a near-total absence of emotional expression,...
Stress Prevention and Stress Management Techniques II
Type A Personality: Driven and Easily Stressed
Individuals with Type A personalities are often highly competitive and ambitious and operate with a strong sense of urgency. Commonly labeled as "workaholics," they...
Generalized Anxiety Disorder
