Decreased thalamic volumes in adolescent inhalant users from Korea and Australia

Abstract

Objectives. Research investigating the impact of inhalant misuse on brain structure suggests abnormalities in subcortical regions. We investigated the association between inhalant misuse and subcortical brain volumes in adolescents. Methods. Based on a collaborative dataset from South Korea (inhalant users: N = 15, mean age = 16.7, SD = 1.1; controls: N = 15, mean age = 15.4, SD = 1.2) and Australia (inhalant users: N = 7, mean age = 18.2, SD = 1.4; controls: N = 7, mean age = 18.9, SD = 2.6), the volumes of caudate nucleus, putamen, pallidum, amygdala, hippocampus, and thalamus were estimated in adolescent inhalant users and healthy adolescents using FreeSurfer. Results. The results revealed a significantly decreased right thalamic volume in adolescent inhalant users (P = 0.042), along with a trend-level decrease in left thalamic volume (P = 0.061). A negative correlation (r = –0.544; P = 0.036) between thalamic volume and severity of inhalant use (i.e., reduced volumes associated with greater use) was identified among Korean participants. Conclusions. These findings suggest that compared with other subcortical structures, the thalamus is particularly sensitive to damage following chronic inhalant exposure during adolescence.