Suicide results from the confluence of stressors and other risk factors interacting with underlying predispositions or vulnerabilities (i.e. diatheses). Theoretical interrelationships between stressors, risk factors, and diatheses have been outlined by Mann and colleagues in their “stress-diathesis” model of suicide (1999) and extended in more recent work (Mann, 2003). In the stress-diathesis model, impulsivity is the proximal factor leading to suicidal behaviors, but other factors can modify the level of impulsivity to increase the risk for suicidal behaviors (Brent and Mann, 2003; Mann, 2003; Mann et al. 1999). In Mann’s original model of suicidal behavior, poor impulse control mediates the relationship between suicidal planning and suicide attempt. Other factors can modify the level of impulse control and increase the risk for suicidal behaviors (Mann, 2003; Mann et al. 1999). Impulsivity can be modified primarily through: (a) psychiatric state and life events; or (b) serotonin function and substance use. One pathway (A in the figure, below) is associated with psychosocial crises and life events that can lead to depression, hopelessness, and suicidal ideation, thereby worsening impulse control. The other pathway (B)
