A new study finds that specific variations in two genes are linked to suicidal thinking in people taking SSRIs – the most commonly prescribed class of antidepressant medication.
For years, doctors and researchers have known that some patients who take SSRIs have an increased risk of suicidal thoughts. Starting in 2004, the FDA required "black box" labels on these medications, warning that they might cause an increase in suicidal thought and behavior, particularly in children and adolescents.
Researchers hope that learning which genes put an individual at increased risk for suicidal thoughts while taking SSRIs will eventually allow doctors to use genetic screening to determine a patient's risk before prescribing medication. Being able to individualize care in this way would allow for better treatment of depression – which can lead to suicide if left untreated.
Overall, about 6 percent of the 1,915 patients with depression in the study reported that they began to have suicidal thoughts while taking the antidepressant. Fifty-nine percent of the patients who reported suicidal thoughts had at least one version of the suspect genes. Among the patients who had suspect versions of both genes, 36 percent reported suicidal thoughts.
More than 40 percent of the patients who developed suicidal thoughts did not have either of the two suspect genes, indicating that other genes and environmental factors were probably also involved.
The study was led by researchers at the National Institutes of Health's National Institute of Mental Health, and published in the October issue of The American Journal of Psychiatry.