Search for solutions, learning, simulation, and choice processes in suicidal behavior

Abstract

Suicide may be viewed as an unfortunate outcome of failures in decision processes. Such failures occur when the demands of a crisis exceed a person's capacity to (i) search for options, (ii) learn and simulate possible futures, and (iii) make advantageous value-based choices. Can individual-level decision deficits and biases drive the progression of the suicidal crisis? Our overview of the evidence on this question is informed by clinical theory and grounded in reinforcement learning and behavioral economics. Cohort and case-control studies provide strong evidence that limited cognitive capacity and particularly impaired cognitive control are associated with suicidal behavior, imposing cognitive constraints on decision-making. We conceptualize suicidal ideation as an element of impoverished consideration sets resulting from a search for solutions under cognitive constraints and mood-congruent Pavlovian influences, a view supported by mostly indirect evidence. More compelling is the evidence of impaired learning in people with a history of suicidal behavior. We speculate that an inability to simulate alternative futures using one's model of the world may undermine alternative solutions in a suicidal crisis. The hypothesis supported by the strongest evidence is that the selection of suicide over alternatives is facilitated by a choice process undermined by randomness. Case-control studies using gambling tasks, armed bandits, and delay discounting support this claim. Future experimental studies will need to uncover real-time dynamics of choice processes in suicidal people. In summary, the decision process framework sheds light on neurocognitive mechanisms that facilitate the progression of the suicidal crisis. This article is categorized under: Economics > Individual Decision-Making Psychology > Emotion and Motivation Psychology > Learning Neuroscience > Behavior.

Keywords: cognition; decision-making; reinforcement learning; suicide; value-based choice.

FIGURE 1

Stages of the suicidal process. (1) A crisis generates a sense of urgency to resolve the problems through any means possible. Suicide may then be included in the consideration set alongside other potential solutions, based on their prior (cached) values and constraints (cognitive deficits, time pressure): suicidal ideation emerges. (2) The value of each action is updated through learning and simulation, as new information is obtained, outcomes are simulated and solutions are attempted. (3) The choice among actions based on their updated values may lead to suicidal behavior, inaction (appropriately or not), an ineffective action that perpetuates the crisis, or an action that resolves it

FIGURE 2

Consideration set construction. (Top left) Normative account. Ordinate: number of options selected into the consideration set. Abscissa: value reflecting the benefit from eventually selecting the best option or the search cost of set construction. Dashed line reflects the net benefit (modified from Hauser, 2014). (Top right) Effect of urgency and time constraints in a crisis. (Bottom) Effect of limited cognitive capacity