Preliminary examination of gray and white matter structure and longitudinal structural changes in frontal systems associated with future suicide attempts in adolescents and young adults with mood disorders

Abstract

Background: Mood disorders are major risk factors for suicidal behavior. While cross-sectional studies implicate frontal systems, data to aid prediction of suicide-related behavior in mood disorders are limited. Longitudinal research on neuroanatomical mechanisms underlying suicide risk may assist in developing targeted interventions. Therefore, we conducted a preliminary study investigating baseline gray and white matter structure and longitudinal structural changes associated with future suicide attempts.

Methods: High-resolution structural magnetic resonance imaging, diffusion tensor imaging, and suicide-related behavioral assessment data for 46 adolescents and young adults with mood disorders [baseline age_mean = 18 years; 61% female] were collected at baseline and at follow-up (interval_mean = 3 years). Differences in baseline and longitudinal changes in gray matter volume and white matter fractional anisotropy in frontal systems that distinguished the participants who made future attempts from those who did not were investigated.

Results: Seventeen (37%) of participants attempted suicide within the follow-up period. Future attempters (those attempting suicide between their baseline and follow-up assessment), compared to those who did not, showed lower baseline ventral and rostral prefrontal gray matter volume and dorsomedial frontal, anterior limb of the internal capsule, and dorsal cingulum fractional anisotropy, as well as greater decreases over time in ventral and dorsal frontal fractional anisotropy (p < 0.005, uncorrected).

Limitations: Sample size was modest.

Conclusions: Results suggest abnormalities of gray and white matter in frontal systems and differences in developmental changes of frontal white matter may increase risk of suicide-related behavior in youths with mood disorders. Findings provide potential new leads for early intervention and prevention strategies.

Keywords: Bipolar Disorder; Depression; Diffusion Tensor Imaging; Magnetic Resonance Imaging; Suicide.