WOMEN are more likely to become addicted to cannabis because the sex hormone oestrogen makes them enjoy the high more, a study has found.

Men are up to four times more likely to try cannabis and use higher doses, more frequently, due to their levels of testosterone, the review of studies into animal behaviour revealed.

Despite females using the drug less, they went from first hit to habit faster than males. This is due to being more sensitive to the drug’s effects and the release of the “pleasure” and “reward’ brain chemicals.

The differences between how cannabis affects the sexes is important as more countries look to decriminalise or legalise cannabis. This month, Canada became the second country to legalise the drug for recreational use.

The research found the differences in response were down to the influence of sex hormones like testosterone, oestradiol (oestrogen) and progesterone on the endocannabinoid system.

This is a network of brain cells which communicate using the same family of chemicals found in cannabis. Study co-author Dr Liana Fattore, of the National Research Council of Italy, said: “Male sex steroids increase risk-taking behaviour and suppress the brain’s reward system, which could explain why males are more likely to try drugs, including cannabis.”

She added: “Females seem to be more vulnerable, at a neurochemical level, in developing addiction to cannabis.”

The findings could lead to gender-based drug addiction treatments.

Professor Fattore told the journal Frontiers in Behavioural Neuroscience: “Identifying factors is critical for optimising evidence-based prevention and treatment protocols.”