Report summary - Mood and Anxiety Disorders in Canada, 2016

Highlights

• Mood and Anxiety Disorders in Canada, 2016¹ provides national annual prevalence estimates of health service use for mood and anxiety disorders over a 14-year period (1996/97 to 2009/10) and by age, sex and geography for the latest year of data (2009/10). It also offers information on the prevalence of comorbidities among those who use health services for mood and anxiety disorders and surveillance challenges specific to these disorders.

• According to key findings of the report, approximately 1 in 10 (3.5 million) Canadians used health services annually for mood and anxiety disorders, and higher rates were observed among adolescent and adult females, middle-aged and older adults and those with other chronic conditions, particularly asthma and chronic obstructive pulmonary disease.

• The report addresses an important knowledge gap by describing health service use for mood and anxiety disorders among Canadian children and adolescents by providing data on those under the age of 15 years.

• The report demonstrates the Public Health Agency of Canada’s commitment to improving data collection and reporting about mental illness, as recommended within Changing Directions, Changing Lives – The Mental Health Strategy for Canada.

Purpose of this report

Mood and Anxiety Disorders in Canada, 2016¹ is the first publication to include administrative health data from the Canadian Chronic Disease Surveillance System (CCDSS) for the national surveillance of mood and anxiety disorders among Canadians aged one year and older. It features nationally complete CCDSS data up to fiscal year 2009/10, as well as trend data spanning over a decade (1996/97 to 2009/10). The data presented in this report, and subsequent updates, can be accessed via the Public Health Agency of Canada’s Chronic Disease Infobase Data Cubes at www.infobase.phac-aspc.gc.ca. Data Cubes are interactive databases that allow users to quickly create tables and graphs using their Web browser. The report demonstrates the Public Health Agency of Canada's commitment to improving data collection and reporting about mental illness, as recommended within Changing Directions, Changing Lives – The Mental Health Strategy for Canada.²

Mood and anxiety disorders

Mood and anxiety disorders are the most common types of mental illnesses in Canada and throughout the world. Mood disorders are characterized by the lowering or elevation of a person’s mood, while anxiety disorders are characterized by excessive and persistent feelings of apprehension, worry and even fear. Both types of disorders may have a major impact on an individual’s everyday life and can range from single, short-lived episodes to chronic disorders. Professional care combined with active engagement in selfmanagement strategies can foster recovery and improve the well-being of people affected by these disorders, ultimately enabling them to lead full and active lives.

Canadian Chronic Disease Surveillance System

The CCDSS is a collaborative network of provincial and territorial chronic disease surveillance systems, supported by the Public Health Agency of Canada. It identifies chronic disease cases from provincial and territorial administrative health databases, including physician billing claims and hospital discharge abstract records, linked to provincial and territorial health insurance registries. The health insurance registries capture data on all residents who are eligible for provincial or territorial health insurance (about 97% of the Canadian population); thus, the CCDSS coverage is near-universal. Case definitions are applied to these linked databases and data are then aggregated at the provincial and territorial level before being submitted to the Public Health Agency of Canada for reporting at the provincial, territorial and national levels.

In 2010, the CCDSS was expanded to track and report on mental illness overall, as well as mood and anxiety disorders in the Canadian population. The CCDSS identified individuals as having used health services for mood and anxiety disorders if they met a minimum requirement of at least one physician claim, or one hospital discharge abstract in a given year listing diagnostic codes for mood and anxiety disorders from the 9th or 10th edition of the World Health Organization’s International Classification of Diseases. Due to the lack of specificity in the diagnoses and data capture, the surveillance of mood and anxiety disorders as separate entities was not possible. Therefore, the report uses the term “mood and anxiety disorders” to refer to those who have used health services for mood disorders only, anxiety disorders only or both mood and anxiety disorders.

The CCDSS may capture individuals who do not meet all standard diagnostic criteria for mood or anxiety disorders but were assigned a diagnostic code based on clinical assessment. Conversely, the CCDSS does not capture individuals meeting all standard diagnostic criteria for mood or anxiety disorders who did not receive a relevant diagnostic code (includes those who sought care but were not captured in provincial and territorial administrative health databases and those who have not sought care at all). For these reasons, the CCDSS estimates represent the prevalence of health service use for mood and anxiety disorders, rather than the prevalence of diagnosed mood and anxiety disorders.

Key findings

About three-quarters of Canadians who used health services for a mental illness annually consulted for mood and anxiety disorders. In 2009/10, almost 3.5 million Canadians (or 10%) used health services for mood and anxiety disorders. Although high, the proportion of Canadians using health services for these disorders remained relatively stable between 1996/97 and 2009/10 (age standardized prevalence ranged from 9.4%–10.5%). The highest prevalence was observed among those aged 30 to 54 years, followed by those 55 years and older, while the largest relative increases in prevalence were found among children and youth (aged 5–14 years); in absolute terms, however, these increases were less than one percent.

Adolescent and adult females, especially those middle-aged, were more likely to use health services for mood and anxiety disorders compared to males of the same age. A combination of behavioural, biological and sociocultural factors may explain this sex difference. Males aged 5 to 9 years were more likely to use health services for mood and anxiety disorders compared to females of the same age. This may be explained by the frequent cooccurrence of mood and anxiety disorders with conduct and hyperactivity attention deficit disorders, which are more commonly diagnosed in males of this age.

In 2009/10, Nova Scotia had the highest age-standardized prevalence of the use of health services for mood and anxiety disorders (11.6%), while the lowest was observed in the Northwest Territories (5.8%). Provincial and territorial variations were observed over the surveillance period, including a significant annual increase in the age-standardized prevalence in Saskatchewan, Manitoba, New Brunswick, Nova Scotia, Prince Edward Island and Newfoundland and Labrador, and a significant annual decrease in Ontario. These jurisdictional variations may in part be explained by differences in detection and treatment practices as well as differences in data coding, database submissions, remuneration models and shadow billing practices.

A higher prevalence of asthma and chronic obstructive pulmonary disease (COPD), and to a lesser degree ischemic heart disease, diabetes and hypertension, was observed among people who used health services for mood and anxiety disorders compared to those who did not. While the relationships remain poorly understood, it is well recognized that people with depressive and anxiety disorders are at increased risk of developing other chronic diseases or conditions, and that people affected by chronic physical diseases or conditions are at increased risk of experiencing depression and anxiety.

Future plans

Future work involving the CCDSS related to mood and anxiety disorders includes the ongoing collection and reporting of data on mood and anxiety disorders; developing an approach to study the chronicity of mood and anxiety disorders; and exploring other comorbid diseases and conditions.

Acknowledgements

Mood and Anxiety Disorders in Canada, 2016¹ was made possible by the contributions of both past and present members of the CCDSS Mental Illness Working Group, CCDSS Science Committee, Mental Illness Surveillance Advisory Committee and CCDSS Technical Working Group.

It was also made possible through collaboration between PHAC and the respective governments of Alberta, British Columbia, Manitoba, New Brunswick, Newfoundland and Labrador, Nova Scotia, Northwest Territories, Ontario, Prince Edward Island, Quebec and Saskatchewan. The opinions, results, and conclusions in this report are those of the authors. No endorsement by the above provinces and territory is intended or should be inferred.