Cortical thickness in parietal regions link perseverative thinking with suicidal ideation

Introduction: Suicide represents a major public health concern, as the tenth leading cause of death in the United States. Links between perseverative thinking (PT) and suicidal ideation have previously been examined, while their biological underpinnings remain understudied. The present study had two aims: 1) investigate whether cortical thickness varied as a function of PT, and 2) examine whether variation in thickness partially explained associations between PT and lifetime history of ideation. We hypothesized that cortical thickness would vary as a function of PT and PT would be positively associated with lifetime history of ideation. Methods: A community sample of 73 adults (ages 18-55; 42.5% female) completed self-report measures examining PT and ideation, as well as a neuroimaging protocol. Mean scores on the Perseverative Thinking Questionnaire were entered as the explanatory variable in the analysis of cortical thickness clusters related to PT. The indirect effect of PT on ideation through thickness was tested cross-sectionally. Results: PT was positively associated with i) thickness in three clusters bilaterally in the parietal cortex and ii) suicidal ideation. Follow-up analyses revealed a significant indirect effect of PT on suicidal ideation through left superior parietal thickness. Limitations: Limitations of the study include the use of cross-sectional data and a modest sample size. Conclusions: PT is associated with variations in cortical thickness, and increased thickness in the left parietal region may partially explain the link between PT and suicidal ideation, identifying a novel neurobiological mechanism of ideation.

Automated summary

This study investigates the association between perseverative thinking (PT) and suicidal ideation, as well as their biological underpinnings. The findings suggest that PT is associated with variations in cortical thickness, with increased thickness in the left parietal region partially explaining the link between PT and suicidal ideation.