Does cannabis-induced psychosis really differ by gender? Yes, according to a recent study published by Hamilton and colleagues at the Univeristy of York. This paper drew together key literature and NHS data regarding cannabis psychosis admissions, to discover males were 4 times more likely than females to be admitted to hospital with a diagnosis of cannabis psychosis. These elevated rates were consistent over 11 years of study period.

This profound gender difference is puzzling as men are only twice as likely as women to use cannabis, suggesting it is not the rate of use which influenced this gender difference.

Why could this be? (As this result is new and unexpected all conclusions, at this stage, are speculative):

• Staff may be more vigilant for problems with cannabis in men which distort the number diagnosed and treated
• Women with children may avoid seeking treatment in fear that their children could be taken into care. This is particularly interesting as cannabis psychosis is related to persecutory delusions and paranoia which may support these delusions and further reduce help-seeking
• Hormone oestrogen may be a protective factor for women in relation to psychosis
• Research has suggested that the incidence of schizophrenia is higher in males than females
• Help-seeking in males is poorer. For example, females may help-seek for moderate mental health difficulties, compared to males of whom may not seek help until mental health becomes more severe

Within SPRiG we run CIRCLE trials (Contingency Management for Cannabis Use). This investigates how effective contingency management can help young people experiencing a first episode of psychosis to reduce the negative effects of cannabis use. If you would like to find out more, or get involved please click here.