Should ketamine be used in the emergency room to treat suicidal patients?

In an article published recently in the American Journal of Psychiatry, Samuel Wilkinson and colleagues examined the effect of ketamine in reducing suicidalideations. They utilized a technique called meta-analysis to combine data from ten clinical studies that fulfilled specific rigorous criteria. They found that a single intravenous infusion of ketamine, at doses akin to those used in other studies to treat major depression, led to a rapid decrease in suicidal ideations. Within a day, about 55 percent of individuals who received ketamine no longer had suicidal ideations, compared to 20 percent who received a placebo. This reduction in suicidal ideations lasted for at least seven days.

Does this mean that emergency room physicians should routinely administer infusions of ketamine to patients who voice suicidal ideations? Should ketamine be used as an anti-suicide medication regardless of the patient’s diagnosis or the circumstances associated with the suicidal ideations?

At least for now, our opinion is an emphatic “no.” Let us explain.

Several disorders are associated with suicidal ideation and completed suicide, including depressive disorders, substance use disorders, and certain personality disorders. Short-term and long-term treatments differ for these illnesses. Suicidal ideation associated with a major depressive episode substantially increases the risk for medically or psychologically significant suicide attempts. The degree of risk varies as a function of age and gender. For example, elderly men with depression and suicidal ideations are at high risk for killing themselves. Although administering ketamine in the emergency room might lower suicidal ideations and decrease depressive symptoms, would it be safe to discharge such an individual without observing them on a psychiatric inpatient unit first and seeing how they do over several days?

Suicidal ideations are a common reason why some individuals with personality disorders (for example, borderline personality disorder) seek treatment in the emergency room. Most research investigating the influence of ketamine on suicidal ideations has involved patients with major depression. Data do not exist about the effectiveness of ketamine in patients suffering from a personality disorder in the absence or presence of major depression. These individuals frequently benefit from counseling that helps to alleviate current stressors. With appropriate support and follow-up arrangements, the individual often can be discharged from the emergency room. It is unknown what a ketamine infusion would do in these circumstances. Would it alleviate the suicidal ideation? Would it give the treatment team the sense that they could substitute an infusion of ketamine for a careful diagnostic interview and counseling?

There is also no information available about the use of ketamine for suicidal ideation in patients with substance-use disorders. These disorders are major contributors to completed suicides, and ketamine itself is an abused drug. It also remains unclear what to do for patients who have recurrent suicidal ideation. Should they be exposed to repeated infusions of ketamine? At what interval can they be treated safely, and what are the risks of repeated ketamine infusions?

In our opinion, administering an infusion of ketamine to a suicidal patient in an emergency room and then discharging the patient a few hours later isn’t, in general, a good therapeutic approach. More research is needed to determine the influence of ketamine in individuals with and without major depression, as well as its influence on the prognosis of a person presenting to the emergency room with depression and suicidal thoughts.

This column was written by Eugene Rubin M.D., Ph.D., and Charles Zorumski M.D.