Clinical trials for rapid changes in suicidal ideation: Lessons from ketamine

New pharmacotherapies to tackle the unmet needs in bipolar disorder: a focus on acute suicidality

INTRODUCTION

Suicidal behavior is relatively frequent in patients with bipolar disorder (BD) and constitutes their most frequent cause of death. Suicide rates remain high in patients with BD despite adherence to guidelines recommending lithium as first line, and/or antidepressants, antipsychotics, psychotherapy, psychosocial interventions, and electroconvulsive therapy. Hence the need to identify more effective and rapid anti-suicide interventions.

AREAS COVERED

To tackle the unmet needs of pharmacotherapy, we investigated the PubMed database on 24-25 January 2024 using strategies like ('acute suicid*'[ti] OR 'suicide crisis syndrome' OR 'acute suicidal affective disturbance') AND (lithium[ti] OR clozapine[ti]), which obtained 3 results, and ('acute suicid*'[ti] OR 'suicide crisis syndrome' OR 'acute suicidal affective disturbance') AND (ketamine[ti] OR esketamine[ti] OR NMDA[ti] OR glutamat*[ti]), which yielded 14 results. We explored glutamatergic abnormalities in BD and suicide and found alterations in both. The noncompetitive NMDS antagonist ketamine and its S-enantiomer esketamine reportedly decrease acute suicidality.

EXPERT OPINION

Intranasal esketamine or subcutaneous ketamine, single-bolus or intravenous, and possibly other glutamate receptor modulators may improve suicidal behavior in patients with unipolar and bipolar depression. This may be achieved through prompt remodulation of glutamate activity. The correct use of glutamatergic modulators could reduce acute suicidality and mortality in patients with BD.

Suicide and Suicide Risk in Adolescents

Suicide is the second leading cause of death for 10- to 24-year-olds in the United States and is a global public health issue, with a recent declaration of a National State of Emergency in Children's Mental Health by the American Academy of Pediatrics, American Academy of Child and Adolescent Psychiatry, and Children's Hospital Association. This clinical report is an update to the previous American Academy of Pediatrics clinical report, "Suicide and Suicide Attempts in Adolescents." Because pediatricians and pediatric health care providers are at the front line of care for adolescents amid a child and adolescent mental health crisis, and because of the chronic and severe shortage of mental health specialists, it is important that pediatric health care providers become facile with recognizing risk factors associated with suicidality and at-risk populations, screening and further assessment of suicidality as indicated, and evidence-based interventions for patients with suicidal ideation and associated behaviors. Suicide risk can be mitigated by appropriate screening, bolstering of protective factors, indicated treatment, community resources, and referrals to mental health providers when available.

Microglia as a Hub for Suicide Neuropathology: Future Investigation and Prevention Targets

Suicide is a complex public health challenge associated worldwide with one death every 40 s. Research advances in the neuropathology of suicidal behaviors (SB) have defined discrete brain changes which may hold the key to suicide prevention. Physiological differences in microglia, the resident immune cells of the brain, are present in post-mortem tissue samples of individuals who died by suicide. Furthermore, microglia are mechanistically implicated in the outcomes of important risk factors for SB, including early-life adversity, stressful life events, and psychiatric disorders. SB risk factors result in inflammatory and oxidative stress activities which could converge to microglial synaptic remodeling affecting susceptibility or resistance to SB. To push further this perspective, in this Review we summarize current areas of opportunity that could untangle the functional participation of microglia in the context of suicide. Our discussion centers around microglial state diversity in respect to morphology, gene and protein expression, as well as function, depending on various factors, namely brain region, age, and sex.

Evaluating the Role of Ketamine/Esketamine in the Management of Major Depressive Disorder with Suicide Risk

Nearly 5% of individuals in the USA had serious thoughts of suicide in 2019 and over 30% of individuals suffering with major depressive disorder reported suicidal ideation with 2 million of those reporting suicidal ideation with some level of intent. However, options to treat depressed individuals considered at imminent risk of suicide remain limited. Until the recent approval of esketamine in the treatment of patients with major depressive disorder with serious suicidal thoughts or actions, no medications had been specifically evaluated for use in this population in the acute setting. This review discusses the history and the current understanding of the role of ketamine and esketamine in depression and suicidal ideation and behavior. It covers some of the pivotal studies in this field and provides a summary of their major findings. The trials of esketamine in patients with major depressive disorder with active suicidal ideation or behavior are the first large-scale trials in patients considered at imminent risk of suicide. As such, the design of these studies is by definition novel, a fact that complicates the interpretation of the data and assessment of the true clinical meaningfulness of the findings. Despite this, the findings in toto draw a consistent picture of benefits that appears to outweigh the potential risks of the treatment. The studies also serve to highlight the complexities and limitations associated with clinical trials aiming to test the ability of novel therapeutics to reduce the burden and risks in patients with suicide ideation and behavior.