Cannabis Increases Spontaneous Mind-Wandering and Impairs the Ability to Control It

In a three-session ABA design (abstinent-cannabis-abstinent), cannabis use was associated with a large increase in spontaneous mind-wandering during a metronome timing task. When instructed to mind-wander 20% or 80% of the time, cannabis reduced participants' ability to adjust their deliberate mind-wandering and task performance to match instructions, suggesting impaired regulation of attention.

Regular cannabis users completed three remote sessions: two on planned abstinence days and one immediately after planned cannabis use. Each session included three blocks of the Metronome Response Task with intermittent self-reports of spontaneous and deliberate mind-wandering. Participants used legally purchased pre-rolls.

Mind-wandering is linked to creativity but also to accidents, poor learning, and mental health challenges. This study provides direct evidence that cannabis not only increases spontaneous mind-wandering but specifically impairs the ability to control it, which has practical implications for activities requiring sustained attention.

The distinction between spontaneous (uncontrolled) and deliberate (intentional) mind-wandering is important. Cannabis appears to primarily increase the uncontrolled type while impairing the ability to regulate attention, which could explain reported difficulties with focus and task completion during cannabis use.

Remote study design relies on self-report. No placebo control (participants knew when they used cannabis). Cannot control for dose, strain, or potency. Naturalistic use means variable exposure. Regular users may not represent occasional users.