
- Vol 32 No 10
- Volume 32
- Issue 10
The Serotonin Transporter Gene: What's New?
Striking findings on the relationship between stress and depression.
BRIEF COMMUNICATION
The story of the serotonin transporter gene length difference and depression has a long history, which I
Recently, another study––one of the few to investigate this relationship in bipolar disorder––replicated Caspi and associates’ main finding.
Several features warrant attention in this study.3 First, it shows that this relationship holds in bipolar as well as unipolar mood disorders. Second, the replication strengthens the original observation in the Caspi study. But this time, another finding that had been hinted at in other studies was very powerfully demonstrated: the S allele was associated with substantially lower rates of suicide attempt, relative to the long L allele, when childhood adversity scores were low. This finding is shown schematically in the Figure.
The same relationship was seen whether number or severity of stressors was used, as quantified by the Social Readjustment Rating Scale, a validated instrument for assessing life-changing events.
Although this finding had been
On the other hand, if the childhood environment is harsh, a propensity toward high-risk behaviors is fostered (the S allele under these circumstances is associated with earlier sexual activity and more substance use, for example).5,6
A final striking finding: the relationship between severity of stressors and suicide attempts, shown schematically in the Figure, follows a remarkably linear relationship. The graphed lines are not just smoothed curves for a scattering of data points, as one so often sees. In this study, each data point follows the previous one precisely along the curves shown here. The connection between the 2 variables seems exceptionally strong.
This article was originally posted on 9/10/2015 and has since been updated.
Disclosures:
Dr Phelps is Director of the Mood Disorders Program at Samaritan Mental Health in Corvallis, OR. He is the Bipolar Disorder Section Editor for Psychiatric Times.
References:
1. Phelps J. Knowing one’s genome: are we ready? Psychiatric Times. July 31, 2015.
2. Caspi A, Sugden K, Moffitt TE, et al. Influence of life stress on depression: moderation by a polymorphism in the 5-HTT gene. Science. 2003;301:386-389.
3. Benedetti F, Riccaboni R, Poletti S, et al. The serotonin transporter genotype modulates the relationship between early stress and adult suicidality in bipolar disorder. Bipolar Disord. 2014;16:857-866.
4. Belsky J, Jonassaint C, Pluess M, et al. Vulnerability genes or plasticity genes? Mol Psychiatry. 2009;14:746-754.
5. Kogan SM, Beach SR, Philibert RA, et al. 5-HTTLPR status moderates the effect of early adolescent substance use on risky sexual behavior. Health Psychol. 2010;29:471-476.
6. McHugh RK, Hofmann SG, Asnaani A, et al. The serotonin transporter gene and risk for alcohol dependence: a meta-analytic review. Drug Alcohol Depend. 2010;108:1-6.
Articles in this issue
almost 10 years ago
Forensic Psychiatry: An Essential Major Subspecialtyalmost 10 years ago
Parents Who Kill: Clinical and Legal Perspectivesalmost 10 years ago
Children of High-Conflict Divorce Face Many Challengesalmost 10 years ago
The Intersection of Geriatric and Forensic Psychiatryalmost 10 years ago
Forensic Evaluations: Testamentary Capacityalmost 10 years ago
Addiction, AIDS, and NIDA’s Overseas Programalmost 10 years ago
Climate Change and Mental Healthalmost 10 years ago
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