The Four Factors that Lead to (and Protect Against) Suicide
The ultimate answer to “Why do people become suicidal?” is complex, and as depicted in the figure below, research has focused on several long- and short-term risk factors that interact to place an individual at increased suicide risk.
1. Social Determinants
Healthy connectedness with family members, neighborhoods, cultural groups and society can serve as a protective factor against suicide. Conversely, social isolation is associated with increased risk. Social networks can be leveraged to promote protective influences across all ages. Young people’s attachment to their family and schools can serve as a protective factor with “school-connected” teens exhibiting a decreased risk for suicidal behavior over time. Interventions that increase healthy connections have been related to reduced suicide risk in older Japanese adults.
At the same time, certain types of social networks can relate to increased suicide risk, both in person and via media influences. Social networks can contribute to a “contagion” of suicidal behavior, potentially through imitation, idealizing and/or by ‘normalizing’ suicidal behavior. Media reporting of high-profile suicides also carries a concern for increased suicidal behavior.
2. Clinical Factors
Research has identified a host of clinical suicide risk factors. Psychiatric risk factors for suicide include depression, anxiety, post-traumatic stress and addiction; physical symptoms include pain and insomnia. Suicide has been associated with specific cognitive symptoms such as suicidal thoughts, making a plan, hopelessness, feeling like a burden and impulsiveness. However, it is important to note that the vast majority of people with behavioral health and physical illness diagnoses do not kill themselves.
3. Neurocognitive Factors
There is a connection between suicide attempts and deficits in basic cognitive functions (e.g., attention, memory), executive performance (e.g., conceptual processes, reversal learning), impulse control, decision-making and implicit thought processes (e.g., implicit associations, like preference and self-esteem). The neurocognitive findings associated with suicide risk include motor impulsivity, decision-making, response inhibition, flexibility of response generation, self-monitoring/error-processing, sensitivity to others’ anger, impaired response to positive emotional stimuli, harm avoidance and an inability to delay rewards. Recent research demonstrates that teens who attempt suicide may have impaired decision making on tasks such as the Iowa Gambling Test.
None of these factors has been determined to be entirely specific to suicide—whether or not these factors can be used reliably as clinical predictors remains to be seen.
4. Biomarkers that Reflect Biological Processes
Early research provided some evidence that suicidal behavior is heritable. Twin studies report 36-43 percent heritability; non-fatal suicide attempts have heritability estimates of 17-45 percent, even after controlling for any psychiatric disorders. In addition, children are five times more likely to attempt suicide if a parent has a history of suicide attempts, and it may relate to impulsive aggression. Another example of tragic and toxic parent-child outcomes, between 10-40 percent of individuals who experience suicidal thoughts and behavior have a child abuse history.
Immune factors, patterns of brain activity observed with imaging and genetic variants, have all been studied to identify biomarkers that can help predict risk or resilience. Current research trends include serotonergic functioning, glutamatergic functioning and responsiveness to stress in the HPA (hypothalamic–pituitary–adrenal) axis, which may be linked to childhood traumatic experiences.
At this point in time, there is no biomarker with diagnostic clinical utility.
There is a great deal to be hopeful about with regard to improving our understanding of why people consider and try to kill themselves. For more information and detailed citations on the information presented above, see the full Prioritized Research Agenda for Suicide Prevention: An Action Plan to Save Lives.
On January 29, the National Council launched a six-part webinar series highlighting the National Action Alliance for Suicide Prevention’s Prioritized Research Agenda for Suicide Prevention: An Action Plan to Save Lives. This series is a collaborative effort between the National Council for Mental Wellbeing, National Action Alliance for Suicide Prevention and the National Institute of Mental Health. Subsequent webinars will describe how this current understanding influences detecting those at risk, clinical care and services, as well as highlighting a number of the pressing research needs to reduce the burden of suicide. For more information about this webinar series, see Linda Rosenberg’s recent blog post announcing this collaboration.
Register for upcoming webinars in this series:
Thur., April 2: What interventions prevent suicidal behavior?
Wed., April 29: What are the most effective services to treat and prevent suicidal behavior?
Wed., May 27: What suicide interventions outside of healthcare settings reduce risk?
Wed., June 24: What research infrastructure do we need to reduce suicidal behavior?
For more information about why people become suicidal, view the recording of our first webinar in a series of six, “Why Do People Become Suicidal?”
The National Action Alliance for Suicide Prevention is the public-private partnership advancing the National Strategy for Suicide Prevention (NSSP). This is achieved by catalyzing implementation of high priority NSSP objectives. One such example is the Action Alliance’s Research Agenda. This groundbreaking document advances NSSP objective 12.1- Develop a national suicide prevention research agenda with comprehensive input from multiple stakeholders.