Lithium may help curb impulsive decisions tied to suicide risk, study finds

A new study finds that brain electrical activity tied to impulsive decision-making — a key contributor to suicide risk — changes after lithium treatment in people who have survived a life-threatening suicide attempt. The findings from Texas A&M University and Baylor College of Medicine were published in Experimental and Clinical Psychopharmacology.

Dr. Nicholas Murphy, co-first author and research associate professor in the Department of Psychiatry and Behavioral Sciences at Texas A&M, worked with researchers in psychiatry and emergency medicine at Baylor College of Medicine to study patients who had survived medically severe suicide attempts using electroencephalography (EEG), a noninvasive test that records electrical brain waves.

Lithium has long been used to treat patients with bipolar disorder and has been associated with reduced suicide risk, but its effects on brain function have not been well studied. In the study, researchers examined brain electrical activity before and after a short course of lithium and compared the results to demographically similar individuals without a history of severe suicide attempts.

Participants at high risk of a recurrent suicide attempt were recruited from the Ben Taub Emergency Center and Michael E. DeBakey Department of Veterans Affairs Medical Center, and they were matched with psychiatric controls. In a double-blind, randomized, placebo-controlled crossover trial, participants received lithium and placebo pills while researchers monitored brain waves using EEG. Researchers found that patients with a history of medically severe suicide attempts showed higher levels of impulsivity and other indicators of heightened arousal at baseline. Decision-making improved after lithium treatment, with corresponding changes in brain signals linked to impulse control.

The results showed that lithium strengthened brain signals tied to decision-making and impulse control, giving patients more time to think before acting. The team believes earlier identification of suicide risk and intervention with lithium may help reduce the likelihood of suicidal behavior.

Murphy said the goal of the research was to better understand whether suicide risk is tied to underlying biological traits such as impulsivity.

“Our hypothesis was that if these patients with a history of suicide were at risk for recurrent attempts due to being more impulsive, EEG would probably be a good, simple way of getting a first pass of understanding why,” he said. “What we found is that lithium gives people more time to think and they’re less likely to make a decision that’s impulsive. This could be utilized in a clinical trial setting to measure target engagement of lithium.”

To the researchers’ knowledge, this is the first human study to demonstrate lithium-associated changes in EEG brain signals in individuals with recent suicidal behavior.

Suicide is the second leading cause of death in people between the ages of 10 and 34, according to the Centers for Disease Control and Prevention. Researchers say one of the biggest challenges is identifying individuals at risk before a first or repeat attempt.

Dr. Alan Swann, senior author and professor in the Menninger Department of Psychiatry and Behavioral Sciences at Baylor, said emergency departments may offer a critical opportunity for earlier detection and intervention.

“If we catch things early, we can prevent it, and that’s why I think emergency medicine is such an important aspect of suicide prevention,” he said. “The first attempt often occurs before the person ever saw a psychiatrist or had an appointment made. Unfortunately, the diagnosis that was proposed of suicidal behavior disorder required that somebody had made previous suicide attempts, which is self-defeating. We have to do something so we’re finding risk as early as possible.”

Dr. Ynhi Thomas, co-first author and assistant professor in the Henry J.N. Taub Department of Emergency Medicine at Baylor, said many patients may not have access to mental health care, and social determinants of health issues may further limit that access. For some patients, the emergency department may be the first place they present with a suicidal crisis or the only setting where they can access mental health care. Early intervention in the emergency department may provide more opportunities to connect patients with treatment and support services.

“Our group’s work is identifying a biological basis for suicide, and often with mental health in general, there’s still a lot of stigma there,” she said. “There are measurable biological mechanisms that underlie suicide, which we could potentially target and really help patients.”

Murphy said the next step is to translate the findings into tools that can be used across a range of clinical settings.

“The take-home from this is that suicide is a very complicated process and just because somebody survives a suicide attempt doesn’t mean that it’s the end of the road,” he said. “Impulsivity and decision making appear to improve with lithium, and this is a first stop along the road to understanding where we can go next to develop procedures that will hopefully lead to the best practices in emergency care when somebody is being discharged and going out into the community, where life is chaotic and can easily bring all that stress back.”

Other co-authors and contributors to this research were Dr. Nidal Moukaddam, professor of psychiatry and behavioral sciences at Baylor College of Medicine; Dr. Thomas Kosten, professor of psychiatry and behavioral sciences at Baylor College of Medicine; Dr. Sanjay Mathew, professor and head of psychiatry and behavioral sciences at Texas A&M, along with Ioana Murgulet, Krisha Shah, Julia Engelhardt who are research coordinators on the study team.

By Emma Lawson, Texas A&M University Division of Marketing and Communications