Greater raphe nuclei (RN) serotonin1A binding potential predicted higher suicidal ideation and more lethal suicidal behavior, a recent study found. In a prospective 2-year study, a cohort of 100 patients presenting for treatment of a major depressive episode of at least moderate severity underwent positron emission tomography, using a serotonin1A agonist; a subset of 50 patients also underwent imaging with a serotonin transporter radioligand. Researchers found:
• Of the 100 patients undergoing follow-up for more than 2 years (39 men; 61 women; mean [SD] age, 40.2 [11.2] years), 15 made suicide attempts, including 2 who died by suicide.
• Higher RN serotonin1A binding potential predicted more suicidal ideation at 3 and 12 months and greater lethality of subsequent suicidal behavior.
• Contrary to hypotheses, suicidal intent was not predicted by serotonin1A binding potential in any brain region, and midbrain serotonin transporter binding potential did not predict future attempts, possibly owing to low power.
Citation: Oquendo MA, Galfalvy H, Sullivan GM, et al. Positron emission tomographic imaging of the serotonergic system and prediction of risk and lethality of future suicidal behavior. [Published online ahead of print July 27, 2016]. JAMA Psychiatry. doi:10.1001/jamapsychiatry.2016.1478.