A comprehensive new study has uncovered a deeply concerning escalation in the diagnosis of psychotic illnesses among younger generations, with a particular focus on conditions like schizophrenia. The research, conducted by a consortium of Canadian institutions, analysed extensive hospital data covering 12.2 million residents of Ontario born between 1960 and 2009.
Sharp Increase in Diagnoses Among the Young
Within this vast cohort, approximately 152,000 individuals were diagnosed with a psychotic disorder, categorised as either schizophrenia spectrum disorders or psychosis 'not otherwise specified'. The data reveals a distinct and troubling upward trend in cases for those born from 1980 onwards.
Most alarmingly, new diagnoses in teenagers and young adults aged 14 to 20 soared by 60 per cent between 1997 and 2023. The research indicates that individuals born between 2000 and 2004 were an estimated 70 per cent more likely to receive a schizophrenia diagnosis than their counterparts born in the late 1970s.
Understanding Psychotic Disorders
Schizophrenia is a chronic and severe mental health condition marked by psychotic episodes where sufferers lose touch with reality, often experiencing debilitating delusions and hallucinations. For this study, a person was classified as having a psychotic disorder if they were discharged from hospital with such a diagnosis, or had at least two outpatient visits within a year coded by physicians as psychosis.
The research team, from ICES, North York General Hospital, the Ottawa Hospital Research Institute, and the Bruyère Health Institute, examined diagnoses by age 30. They found those born in the early 1990s were 38 per cent more likely to have a psychosis diagnosis compared to those born in the late 1970s.
Investigating the Potential Causes
Lead author Dr. Daniel Myran emphasised the critical nature of the findings. 'Consequently, the observed trends raise important questions about possible causes and consequences of increasing numbers of psychotic disorder diagnoses,' he stated. 'We don’t yet know what’s driving these changes, and it’s likely there isn’t a single explanation. Understanding what’s behind this trend will be critical to prevention and early support.'
Dr. Myran highlighted substance use as a leading possibility, specifically naming cannabis, stimulants, hallucinogens, and synthetic drugs. 'The use of substances, especially earlier in life, is associated with the development and worsening of psychotic disorders, and substance use in Canada has risen over the past two decades,' he added, noting an undeniable correlation.
The Cannabis Connection
The potential link to cannabis is particularly salient. Figures show it remains the most consumed illegal drug in England and Wales, with an estimated 2.3 million users in the year to March 2024. Separate research published in 2024 indicated adolescents who used cannabis were 11 times more likely to experience a psychotic episode in adulthood.
This concern is echoed by UK experts. Dr. Niall Campbell, a consultant psychiatrist at the Priory rehabilitation centre, warns of a deepening public health issue linked to highly potent cannabis varieties like 'skunk', which are easily accessible online. 'There has been a visible rise in the number of people needing intensive support for psychosis as a result of cannabis use,' said Dr. Campbell.
Other Contributing Factors
Beyond substance use, the researchers propose several other potential contributors to the rising diagnosis rates:
- An increase in social and financial stress experienced by younger generations.
- A higher prevalence of difficult or traumatic childhood experiences.
- The trend of parents having children later in life, which may raise concerns about genetic factors related to sperm and egg quality.
- Improved diagnostic techniques and a better clinical understanding of psychotic conditions, potentially leading to more accurate and frequent identification.
Demographic Patterns and Broader Context
The study, published in the medical journal CMAJ, also identified clear demographic patterns. Overall, men were found to be more likely to develop psychosis than women. Furthermore, individuals diagnosed with schizophrenia were more frequently from lower socioeconomic backgrounds or had a prior history of treatment for mental health problems or substance use.
This research emerges against a backdrop of heightened concern, with several high-profile violent crimes in the UK being linked to psychosis. Cases such as the 2024 killing of schoolboy Daniel Anjorin by a man in a cannabis-induced psychotic episode have brought the severe consequences of these disorders into sharp public focus.
The findings underscore a pressing need for further investigation into the complex interplay of biological, environmental, and social factors driving this alarming trend in youth mental health.
