Cognitive Phenotype Shifts in Risk-Taking: Interplay of Non-Suicidal Self-Injury Behaviors and Intensified Depression

Non-suicidal self-injury (NSSI) behavior is significantly prevalent in both adolescents and psychiatric populations, particularly in individuals with major depressive disorder (MDD). NSSI can be considered a result of risky decision-making in response to negative emotions, where individuals choose self-harm over other less harmful alternatives, suggesting a potential decision-making deficit in those engaging in NSSI. This study delves into the complex relationship between NSSI and depression severity in decision-making and its cognitive underpinnings. We assessed decision behaviors in 57 MDD patients with NSSI, 42 MDD patients without NSSI and 142 healthy controls using the Balloon Analogue Risk Task, which involves risk-taking, learning, and exploration in uncertain scenarios. Using computational modeling, we dissected the nuanced cognitive dimensions influencing decision behaviors. A novel statistical method was developed to elucidate the interaction effects between NSSI and depression severity. Contrary to common perceptions, we found that individuals with NSSI behaviors were typically more risk-averse. Meanwhile, there was a complex interaction between NSSI and depression severity in shaping risk-taking behaviors. As depressive symptoms intensified, these individuals with NSSI began to perceive less risk and behave more randomly. This research provides new insights into the cognitive aspects of NSSI and depression, highlighting the importance of considering the influence of comorbid mental disorders when investigating the cognitive underpinnings of such behaviors, especially in the context of prevalent cross-diagnostic phenomena like NSSI behaviors.