Over the past decade in Victoria, hospital admissions connected to cannabis have climbed notably, with diagnoses of psychotic disorders accounting for a considerable share of that increase. Over the ten years that ended in 2023, hospital admissions across Victoria where cannabis use was recorded as the primary cause climbed by 49 per cent.
Drawing on hospital admission records from 40,000 cases across both public and private facilities, researchers at Monash University arrived at these conclusions, with their work appearing in the journal Addiction. Among the diagnoses recorded, conditions grouped under psychotic disorders — those in which a person may experience hallucinations or a disconnection from reality — accounted for the largest share of primary cases.
Harmful cannabis use contributed a further 15.2 per cent of those admissions, while withdrawal-related cases brought in another 11.6 per cent, with the original category accounting for four in every ten.
Men and boys still account for the greatest share of admissions overall, yet the pace of increase among female patients ran at nearly double the rate recorded for their male counterparts. Over the same ten-year span, hospital admissions for females rose at roughly twice the rate recorded for males — 75 per cent against 35 per cent.
The research stopped short of exploring that gap, though it pointed to data indicating cannabis use had been climbing among women over the same period, with lead author Myfanwy Graham noting that the rise in hospital admissions recorded among women and girls was a pattern that warranted particular attention.
Patients admitted to hospital wards face a different level of care than those treated in emergency departments, with ward stays routinely stretching across several days rather than hours. Of those admitted, upwards of 1,500 cases required a stay in intensive care, with the typical patient remaining hospitalised for roughly seven days.
The study's findings, Graham noted, point to cannabis-related hospital admissions placing a growing burden on health services, with the research underlining the value of targeted public health campaigns and earlier intervention approaches.
Rates of cannabis consumption across Australia have climbed over the past ten years, fed by a combination of unauthorised trade and the expansion of prescription-based access. Trending upward unevenly rather than in a straight line, the data showed pronounced spikes in 2017/18 and, most strikingly, in 2020/21, when the study's authors noted that prolonged lockdown periods may have shaped both substance use patterns and how people engaged with healthcare services, given the pressures those restrictions placed on mental health, household incomes, and social connection.
Hospital records submitted to Victoria's state health department form the underlying data source from which the study draws its findings.
