REM suppression

Direction

• REM time: ↓ (~34 min same night)
• REM latency: ↑ (~66 min increase)
• REM density: reduced in chronic users

Mechanism

CB1 activation in brainstem REM-regulating circuits. Not a clean “sleep booster” — architecture is distorted even when sleep onset feels easier.

Timing

Strongest same night as use. Effects visible even in occasional users with tolerance-adjusted models.

Vitals relevance

One of the strongest secondary wearable markers for cannabis detection. Paired with HR delta, builds a two-signal model (acute event + overnight architecture).

Caveats

• Withdrawal produces opposite sleep pattern (REM rebound, insomnia)
• Heavy chronic users may show attenuated suppression due to tolerance

Related

Cannabis, Sleep architecture, Cannabis detection model, Cannabis withdrawal