Think Tank, March 2013

The James K. Bernard Foundation convened a small think tank of scientists working in the suicide field on March 18, 2013 at the Center for Depression in Aurora, Colorado to advise the foundation regarding its interest in suicide research and prevention. This meeting was instrumental in helping the Board of Directors in its understanding of the state of suicide research, a role that biological factors may play in influencing suicide behavior, and relevant biological pathways and mechanisms that may be involved.

The experts at the think tank made clear that, in comparison to the field of overall mental health research, suicide-specific research is a relatively new and undeveloped field with few scientists, limited funding sources, and minimal investment. Under these circumstances, it has been difficult to recruit and retain researchers, especially young ones, and to build the field. Moreover, the concentration of researchers with an active interest in the biology of suicide is even smaller.

Common characteristics in the suicidal population include psychopathology, notably depression and anxiety, as well as impulsivity and aggression. Since it is behaviorally defined, there are currently no biomarkers of suicidality, and relevant research encompasses a range of behaviors from self-harm, to suicidal ideation, attempts, and completion. Furthermore, suicide is sometimes distinguished between impulsive suicide attempts (quick action without thought of outcomes, varying stimuli, and absent classical warning signs) and compulsive suicide attempts (follows a pattern, usually in response to a specific stimuli, and characterized by repeat attempts). Importantly, most research on risk for suicide behaviors has concentrated on environmental factors that are psycho-social in nature, such as trauma, economic or social losses, bullying, and perceived burdensomeness, to name a few.

Although environmental risk factors that are not psycho-social but biological in nature are beginning to be explored, there is little understanding and no particular consensus on which types of factors may be of high relevance to suicide. However, as think tank participants explained, the idea of biological influences is definitely increasing, especially due to recent findings related to environmental factors such as concussion history and certain pharmacological exposures.

Biological risk factors discussed at the think tank with some data or at least a suspicion of increased risk of suicide behaviors include:

  • Traumatic Brain Injury (TBI)
  • Diet-related factors: low cholesterol levels, reduced Omega 3 fatty acids, caffeine
  • Medications: Mefloquine (used to prevent and treat malaria), pharmaceuticals with black box warnings
  • Medical syndromes: Lesch-Nyhan Syndrome or other metabolic conditions
  • Sleep deprivation and related factors: stress, caffeine
  • Immune-mediated factors: allergies, inflammation
  • Parasites or pathogens: T. gondii
  • Environmental toxins, e.g. pesticides
  • Life style factors: Tobacco/Nicotine/Alcohol/Marijuana use
  • Photoperiod and seasonality: sun exposure, vitamin D, sleep/wake cycles
  • Altitude: decreased O2
  • Sports activity: injury as a risk factor; exercise as protective

Biological pathways under exploration (through which such factors could potentially interact) include:

  • Serotonergic pathways
  • Hypothalamic-Pituitary-Adrenal axis
  • Inflammatory pathways
  • Epigenetic regulation
  • Polyamine system; Cell stress responses
  • Neurotrophins

In addition to published research papers, one resource for further exploration of the pathophysiology of suicide noted by think tank participants is The Neurobiology of Suicide by Yogesh Dwivedi, published in 2012.

While there are scattered research efforts addressing various factors, there has been no multi-disciplinary, combined effort to find a multivariate model to predict suicide risk following exposure to such types of environmental/biological factors. Moreover, just as there are population subgroups with higher rates of suicide behaviors, there may be subgroups with greater susceptibility to suicide risk from particular biological factors. It is recognized that not everyone is susceptible to the same risk factors, that no one factor is a predictor, that dynamic interaction of potentially hundreds of factors is possible, and that most factors are non-specific to suicide. For example, while sleep deprivation is widespread in American culture, only a small subset of sleep-deprived Americans report suicidal ideation, and yet, sleep deprivation is common within the suicidal population.

Think tank consensus was that capacity-building within the field is essential for studies of biological/non psycho-social environmental factors and their influences in high-risk populations, as well as for development of animal models and other research that can evaluate biological pathways and uncover novel methods of suicide prevention, perhaps by decreasing exposure to such factors in susceptible individuals. Building a larger field of epidemiological and biological researchers in suicide has the potential to draw in young investigators, expand the range of approaches, encourage cross-disciplinary collaboration, and promote new additions to the thought processes.

In helping to generate interest and build capacity in this emerging area of suicide research, it would be the hope that JKBF would be able to make a meaningful impact on the understanding of alterable and avoidable environmental risk factors that could reduce suicides and suffering.


We greatly appreciate the contributions of the Think Tank Participants:

Michael H. Allen, MD
Professor, Psychiatry-Depression Center, University of Colorado School of Medicine

Lisa A. Brenner, PhD, ABPP
Director, Rocky Mountain Mental Illness Research, Education and Clinical Center (MIRECC)
Professor, Departments of Physical Medicine and Rehabilitation, Neurology and Psychiatry, University of Colorado, Denver School of Medicine

David Brent, MD
Endowed Chair in Suicide Studies and Professor of Psychiatry, Pediatrics, Epidemiology, and Clinical and Translational Science, University of Pittsburgh School of Medicine

Todd Gould, MD
Associate Professor in the Departments of Psychiatry, Pharmacology, and Anatomy & Neurobiology, University of Maryland School of Medicine

Susan Hepburn, PhD
Professor, Human Development and Family Studies, University of Colorado

Robert Naviaux, MD, PhD
Professor of Genetics in the Departments of Medicine, Pediatrics and Pathology
University of California, San Diego

Remington Nevin, MD
Physician Epidemiologist

Teodor T. Postolache, MD
Professor, Psychiatry, University of Maryland School of Medicine

Lorann Stallones, PhD, MPH
Professor, Director of the Graduate Program in Public Health, University of Colorado, Denver

Gustavo Turecki, MD, PhD
Professor of Psychiatry and Human Genetics, McGill University

Jian Zhang, MD, PhD
Professor, Department of Biostatistics, Epidemiology, and Environmental Health Sciences, Jiann-Ping Hsu College of Public Health, Georgia Southern University