The journey from first using cannabis through to developing mental health problems is very different for men and women. Men outnumber women at every point along the way. Despite these marked gender differences, little attention has been paid to such a basic demographic factor in cannabis psychosis and the underlying reasons for why men fare so poorly.
The first clue might be found in who uses cannabis. The most comprehensive survey of drug use in the UK shows a consistent trend of twice as many men than women reporting that they have used cannabis. But no one really knows why there is a marked variation between the genders when it comes to using cannabis. Some have suggested that drug use carries more social stigma for women than men, and that younger men are also more likely than women to engage in risk-taking behaviour including illicit drug use. Others have said that men are more likely to use drugs and alcohol as a coping mechanism, while women tend to cope with stress by using social support. Differences in the rates of psychosis unrelated to cannabis also mirror the gender differences evident in cannabis users, with males outnumbering females by a ratio of 2:1.
Cannabis has been linked to psychosis for some time and although the debate continues as to the exact nature of the relationship, many people require health and social care for the problems they experience. However, it is interesting that despite the widespread attention that researchers have paid to cannabis psychosis there has yet to be a large scale analysis of the role gender in the condition. To date, seminal research on this issue has focused disproportionately on men or on small samples.
We analysed admissions to hospital in England and found that men are four times more likely than women to be diagnosed with cannabis psychosis. These elevated rates were consistent over the 11 years of the study period.
Bias in treatment
So what might account for this widening of the gender ratio? There are a number of plausible explanations. It could be the result of a bias in treatment services which tend to be dominated by male patients. This is in some ways also linked to the long-standing bias in research involving samples of men because research samples are often drawn from treatment settings out of convenience.
Staff working in mental health services may have also become more attentive to problems associated with cannabis use, and the greater number of men diagnosed and treated for cannabis psychosis may therefore reflect the disproportionate number of men who currently receive treatment for mental health problems. Paradoxically, the excessive number of male patients in services can act as a barrier to women who need treatment, as they frequently have a history of trauma and exploitation perpetrated by men.
It is also likely that women with children will avoid seeking specialist treatment when they develop mental health problems as a result of cannabis use due to the fear that their children may be taken into care, particularly if they have no family support. Likewise, services may be treating such women differently knowing that they have a duty to safeguard these children. Consequently, health and social care services might be offering alternatives to hospital treatment such as community services as a way of maintaining continued contact between mother and child.
And then there is biology, which may also have a role to play. Research has suggested that the female hormone oestrogen may have a protective effect for women in relation to psychosis.
Despite all the unknowns when it comes to cannabis psychosis, gender clearly matters. As well as treating men and reducing the number of people with psychosis, what we now need to work out is whether there are women we need to reach and how best to do it.