Brain Networks Linked to Poor Sustained Attention at Age 14 Predicted Cannabis and Cigarette Use by Age 23

Brain connectivity patterns associated with poor sustained attention at age 14 predicted subsequent increases in cannabis and cigarette use through age 23. Individual differences in attention network strength were preserved across developmental stages and generalized to an external dataset.

Longitudinal study following over 1,000 participants from ages 14 to 23. Brain connectivity during sustained attention tasks was measured using neuroimaging. Attention network patterns at baseline were used to predict substance use trajectories. Results were validated against an external dataset.

This is among the first studies to establish that attention deficits precede cannabis use rather than resulting from it. Identifying a reliable brain biomarker for substance use vulnerability at age 14 could enable targeted prevention before cannabis initiation begins.

The chicken-or-egg question in cannabis-cognition research has been: does cannabis impair attention, or do people with attention problems gravitate toward cannabis? This longitudinal evidence supports the latter, suggesting attention deficits may be a pre-existing vulnerability factor rather than purely a consequence of use.

Although longitudinal, the study cannot fully rule out unmeasured confounders that might independently affect both attention networks and substance use trajectories. The study examined attention broadly rather than parsing specific attention subtypes.