Cannabis and motor skills

Cannabis and motor skills

• cannabis can affect motor control - cannabis also impairs balance, tracking ability, hand-eye co-ordination, reaction time and physical strength
  • with respect to driving, there is evidence that cannabis use increases accident risk (1)
• even a very low dose e.g. 20mg of delta 9-tetrahydrocannabinol (THC) can cause driving skills to deteriorate, and a single joint may deliver as much as 300mg of THC
  • THC is fat-soluble and therefore persists in the body far longer than alcohol - therefore the effects on motor function and co-ordination are persistent
    • airline pilots who were tested after a small dose of 20mg of THC could not land their planes properly on flight simulators, even 24 hours after ingestion - the majority of the pilots were unaware that they had any problems.
• therefore the message relating to cannabis use and motor skills (e.g. driving, flying) is clear — a joint today then do not drive tomorrow
• adverse effects of even a low dose of cannabis combined with alcohol were markedly greater than for either drug alone.

Reference:

1. Drug Alcohol Rev. 2004;23(3):319-44.