Related Experiment Video
Updated: Aug 15, 2026

An Unpredictable Chronic Mild Stress Protocol for Instigating Depressive Symptoms, Behavioral Changes and Negative Health Outcomes in Rodents
Published on: December 2, 2015
Clinical and biochemical aspects of depressive disorders: I. Introduction, classification, and research techniques
S Caldecott-Hazard1, B H Guze, M A Kling
1Laboratory of Biomedical and Environmental Science, University of California, Los Angeles 90024.
Abstract:
The present review focuses on recent data from clinical and animal research concerning the biochemical bases of depressive disorders, diagnosis, and treatment. In addition to integrating these data, problems and future directions in this research are discussed. The review is presented in three parts. This study, Part I, describes diagnostic classification schemes for depressive disorders, some epidemiological and biological correlates of the classifications, and research techniques for investigating depressive disorders. Research techniques include animal models, human biochemical techniques, and Positron Emission Tomography. In a future issue, Part II will discuss various transmitter/receptor theories of depressive disorders, e.g., noradrenergic, serotonergic, cholinergic, and dopaminergic, GABAergic, and peptidergic theories. Also in a future issue, Part III will discuss treatments for depression and some of the controversies in the field.
Related Concept Videos
Depression: Overview
Antidepressant Drugs: Overview
Theoretical Approaches to Psychological Disorder
Biological approach
The biological approach posits that internal, organic factors are the primary causes of such disorders. This perspective emphasizes brain structure and function, genetic predispositions, and neurotransmitter imbalances. For example, schizophrenia has been associated with both genetic...
Depressive Disorders: MDD and Dysthymia
Treatment Strategies for Psychological Disorders
Psychological therapies focus on modifying emotions, thoughts, and behaviors through talking, interpreting, listening, rewarding, challenging, and modeling. Clinical psychologists, counselors, and social workers commonly practice psychotherapy. Clinical...
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...

