Smoking cannabis doesn't only relieve stress, ease pain and cure cancer. Interestingly, a new study suggests marijuana can also improve treatment for heroin addicts.

Metro UK reports a study conducted by researchers at Columbia University investigated the use of cannabis among opioid-dependent subjects who were undergoing in-patient and outpatient detoxification with opioid addiction medication called naltrexone. While some in-patient subjects were given placebo, the others were given dronabinol --- a prescription drug that contains THC.

According to results, those who consumed dronabinol had lower withdrawal symptoms compared to those who had the placebo. Meanwhile, outpatients who used cannabis had reduced sleeping problems, less anxiety and were more likely to finish treatment than those who didn't.

"One of the interesting study findings was the observed beneficial effect of marijuana smoking on treatment retention," the researchers concluded. "Participants who smoked marijuana had less difficulty with sleep and anxiety and were...