BC Schizophrenia Society Shares Schizophrenia Prevalence Position Paper

January 4th, 2024   |   By Alex Wyatt

The prevalence rates, service needs, and social impacts of an illness are often key factors in determining how much funding is allocated for the treatment and services of that illness. The prevalence rates of schizophrenia and other psychotic disorders are often reported differently by other organizations. Based on research compiled from a variety of studies, including a 2023 US study, Mental and Substance Use Disorders Prevalence Study (MDPS), BCSS has released new figures on the prevalence of schizophrenia in Canada. Knowing these numbers and having more accurate statistics allows us to better advocate for funding and services for our community.

Based on recent Canadian and international studies, the BC Schizophrenia Society (BCSS) recommends adopting 1.8% as the schizophrenia prevalence rate for service planning, with the understanding that it could be higher.

You can find the full paper outlining BCSS’ position on the prevalence of schizophrenia here.

We emphasize that lower estimates of schizophrenia prevalence rates need to be considered with caution because underreporting is common due to wide stigma, narrow definitions of severe and persistent mental illness, and the exclusion of certain populations.

HOW WE CAME UP WITH THESE FIGURES

The Canadian Chronic Disease Surveillance System (CCDSS) is a key source for estimating disease prevalence rates across Canada on a national and provincial level. The CCDSS uses data from health insurance registry databases in each province and territory. This information is then linked to billing databases from physicians and hospitals using unique personal identifiers such as health card numbers.

The CCDSS has reported 1.1% and 0.9% as the annual prevalence rates for BC and Canada, respectively, but they acknowledge that their data is “based on people with diagnosed schizophrenia who had contact with the health system during the data collection period” which can lead to total lifetime underestimates.

The likelihood of underreporting schizophrenia prevalence rates based on health system contacts is high since many people with schizophrenia may not have a diagnosis or seek treatment. According to the Treatment Advocacy Centre, an estimated 40% of individuals with schizophrenia are untreated in any given year. Even people with a diagnosis and access to health services may be excluded, depending on the reason for a person’s contact with the health system. Underreporting can also be further exacerbated based on the populations and services that are included.

There are several steps we have taken to minimize and acknowledge underreporting in our prevalence rate, including:

  • considering all schizophrenia spectrum disorders (schizophrenia, schizoaffective disorder, and schizophreniform disorder), which have similar treatment and support service needs;
  • including people in psychiatric hospitals, prisons, and homeless shelters in surveys;
  • and utilizing clinical interviews to identify schizophrenia cases more accurately.

IMPLICATIONS

The increase in our estimated lifetime prevalence for schizophrenia further emphasizes that current service levels are insufficient.

The lack of services required to meet the needs of the approximately 97,000 British Columbians who will be afflicted with schizophrenia at some point in their lives (based on the 1.8% prevalence rate) is even more concerning when the impact of schizophrenia disorders on individuals, families, and communities is considered.

For instance:

Read the full paper here.