Medicinal cannabis users may develop tolerance to drug’s sleep-inducing effects

A new study has found that medicinal cannabis taken by people to help ease chronic pain may cause sleep problems.

Researchers found that when people first began using the drug, they were less likely to wake up during the night than those who did not take cannabis. But the scientists found that with continued use, people built up a tolerance and the effects on sleep were reversed, with users waking up more often during the night than non-users.

People taking the drug also ended up reporting more problems falling asleep than those who didn’t take it.

Many people with multiple sclerosis (MS) self-medicate with cannabis, and medical cannabis is allowed to be prescribed on the NHS for people with MS, but only for muscle stiffness and spasticity, not chronic pain.

The authors said that the study, which was published in the British Medical Journal’s Supportive and Palliative Care Journal, may ‘signal development of tolerance’ of the drug.