Diminished frontal pole size and functional connectivity in young adults with high suicidality

Abstract

BackgroundSuicide rates among young people have been increasing in recent years, yet no validated methods are available for identifying those who are at greatest risk for suicide. Abnormalities in the medial prefrontal cortex have been previously observed in suicidal individuals, but confounding factors such as treatment and chronic illness may have contributed to these findings. Thus, in this study we tested whether the size of the medial prefrontal cortex is altered in suicidal young adults who have received no treatment with psychotropic medications. MethodsSuicidality was evaluated using the Suicide Behaviors Questionnaire-Revised (SBQ-R) and surface areas of four regions-of-interest (ROIs) within the medial prefrontal cortex were measured using magnetic resonance imaging (MRI) in a cohort of college students (n = 102). In addition, a secondary seed-based functional connectivity analysis was conducted using resting-state functional MRI data. Areas and functional connectivity of the medial prefrontal cortex of young adults with high suicidality (HS; SBQ-R score > 7; n = 20) were compared to those with low suicidality (LS; SBQ-R score = 3, n = 37). ResultsCompared to the LS group, the HS group had a significantly lower surface area of the right frontal pole (p < 0.05, Bonferroni-corrected) and significantly lower functional connectivity of the right frontal pole with the bilateral inferior frontal cortex (p < 0.001, Monte-Carlo corrected). LimitationThese findings require replication in a larger sample and extension in younger (adolescent) populations. ConclusionDiminished frontal pole surface area and functional connectivity may be linked to elevated levels of suicidality in young people.