Neurobiological research with suicidal participants: A framework for investigators.

OBJECTIVE: Suicide is a public health threat. Nevertheless, the research literature on actively suicidal participants is relatively sparse, in part because they are often excluded from medical, psychiatric, and psychological research for a host of logistical, ethical, and safety concerns. These obstacles to research participation and enrollment may contribute to our lack of understanding regarding the neurobiology of the suicidal crisis as well as to the dearth of evidence concerning both risk prediction and treatment. METHOD: In order to directly investigate neurobiological markers of acute suicide risk, the National Institute of Mental Health Intramural Research Program (NIMH-IRP) implemented the Neurobiology of Suicide protocol. In this protocol, actively suicidal individuals consent to research for both neurobiological assessment and potential rapid-acting interventions. RESULTS AND CONCLUSIONS: This article reviews lessons learned from implementing this protocol in the hopes of assisting future research on the neurobiology of suicide. Areas of specific discussion include the Failure Modes and Effects Analysis (FMEA), recruitment and informed consent, participant monitoring, and the safety of the physical environment.

Replication of ketamine's antidepressant efficacy in bipolar depression: a randomized controlled add-on trial.

BACKGROUND: Currently, no pharmacological treatments for bipolar depression exist that exert rapid (within hours) antidepressant or antisuicidal effects. We previously reported that intravenous administration of the N-methyl-D-aspartate antagonist ketamine produced rapid antidepressant effects in patients with treatment-resistant bipolar depression. The present study sought to replicate this finding in an independent sample. METHODS: In this double-blind, randomized, crossover, placebo-controlled study, 15 subjects with DSM-IV bipolar I or II depression maintained on therapeutic levels of lithium or valproate received a single intravenous infusion of either ketamine hydrochloride (.5 mg/kg) or placebo on 2 test days 2 weeks apart. The primary outcome measure was the Montgomery-Asberg Depression Rating Scale, which was used to rate overall depressive symptoms at baseline; at 40, 80, 110, and 230 minutes postinfusion; and on days 1, 2, 3, 7, 10, and 14 postinfusion. RESULTS: Within 40 minutes, depressive symptoms, as well as suicidal ideation, significantly improved in subjects receiving ketamine compared with placebo (d = .89, 95% confidence interval = .61-1.16, and .98, 95% confidence interval = .64-1.33, respectively); this improvement remained significant through day 3. Seventy-nine percent of subjects responded to ketamine and 0% responded to placebo at some point during the trial. The most common side effect was dissociative symptoms, which occurred only at the 40-minute time point. CONCLUSIONS: This study replicated our previous finding that patients with bipolar depression who received a single ketamine infusion experienced a rapid and robust antidepressant response. In addition, we found that ketamine rapidly improved suicidal ideation in these patients.