Cognition and self-injurious thoughts and behaviors: A systematic review of longitudinal studies

There is a long tradition in suicide research, accompanied by recent developments in nonsuicidal self-injury (NSSI) research, of examining cognitive processes as potential precursors of risk. But these cognitive processes are often studied separately, and are rarely integrated or directly compared with each other. In an effort to synthesize this literature, this systematic review (n = 109 longitudinal studies conducted over the past 10 years) demonstrates how specific cognitive processes predict self-injurious thoughts and behaviors (SITBs), and examines whether intervening on features of cognition may help mitigate SITB risk. Our review reveals that cognitive processes, measured using self-report and behavioral measures, are most often linked to recurrent suicidal ideation. Overall, several patterns emerged. First, SITB-themed cognitions were robust risk factors and proximally associated with SITB outcomes. Second, negatively-valenced cognitive risk factors were the most commonly studied risk factors, relatively robust, and modestly related to SITB outcomes. Third, cognitive deficits (i.e., basic cognitive processes not characterized by thematic content or negative valence) produced mixed findings that suggest a more distal relationship to SITB outcomes. Moreover, our review of treatment articles revealed that while many interventions are informed by the cognitive literature, potential cognitive mechanisms of treatment change are rarely studied. We conclude by outlining key ways that future research can generate more comprehensive cognitive profiles of self-injurious and suicidal individuals.