BOLD activation during cue induced craving in adolescent inhalant users

Inhalants are legally available substances, most of them inexpensive, which are often abused by adolescents. Craving causes their continued use and repeated relapses. There is a need to understand the cue-induced craving and the associated neural mechanisms. In absence of any such prior study, the present study compared the hemodynamic changes in brain associated with craving effect in adolescent inhalant users and healthy controls using blood oxygen level dependent (BOLD) mechanism. This was an observational case control study with twelve adolescents, aged 12-18 years, with current use of inhalants as their primary drug, and twelve healthy, age and gender-matched adolescents, with no lifetime use of inhalants. Clinical assessments included Teen Addiction Severity Index and Visual Analogue Scale for craving. Participants abstained from all substances during 48 h prior to fMRI, confirmed by urinalysis. A validated visual cue block paradigm with neutral and craving cues was presented during the BOLD assessments in a 3 T MR system. The inhalant users exhibited BOLD activation in inferior frontal gyrus, inferior parietal lobule, superior occipital gyrus, cingulate gyrus, lentiform nucleus, thalamus, and culmen as compared to control group. The control group exhibited activation of insula as compared to cases. The results may be attributed to visuo-spatial attention, visual perception, working memory, and motivation associated with visual cue reactivity. This preliminary study provides important findings pertaining to activation patterns in response to cue-induced craving among adolescent inhalant users.