Related Experiment Video
Updated: Aug 11, 2026

The Forced Swim Test as a Model of Depressive-like Behavior
Published on: March 2, 2015
Life events, first depression onset and the serotonin transporter gene
Kay Wilhelm1, Philip B Mitchell, Heather Niven
1Consultation Liaison Psychiatry, Level 4, DeLacy Building, St Vincent's Hospital, Victoria Street, Sydney, New South Wales 2010, Australia. kwilhelm@stvincents.com.au
Background:
A relationship between the serotonin transporter gene, adverse events and onset of major depression has been reported.
Aims:
To replicate a gene x environment interaction in a cohort with longitudinal data for life events, experience of depression, parental bonding and neuroticism.
Method:
At the 25-year follow-up, genomic DNA was obtained from 127 cohort members (mean age 48 years) to determine the genotype of the serotonin transporter gene-linked promoter region (5-HTTLPR). Associations were investigated between the 5-HTTLPR genotype, positive and adverse life events and the gene x environment interaction, and also between the 5-HTTLPR genotype and risk factors for depression.
Results:
No relationship was found between 5-HTTLPR genotype and either risk factors for depression or positive life events. Adverse life events had a significantly greater impact on the onset of depression for individuals with the s/s genotype.
Conclusions:
The 5-HTTLPR genotype is a significant predictor of onset of major depression following multiple adverse events. This is one of the more robust findings concerning specific biological risk factors for depression.
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...
G-protein Coupled Receptors
Human Genetics
The complex relationship between genetics and psychology is observable through common biological components such...
Depression: Overview
Antidepressant Drugs: MAOIs and Other Agents
Antidepressant Drugs: Tricyclics, SSRIs, and SNRIs

