Data from a series of large, national longitudinal surveys show that symptoms of most mental illnesses in Canadian youth have in fact been stable or declining since 1994, according to a study published in the Canadian Medical Association Journal. So why does the opposite seem to be occurring, asked the authors.
Led by University of Ottawa researchers, the study evaluated data from the National Longitudinal Survey of Children and Youth provided by 11,725 participants from 1994 through 2009. The surveys asked children about feelings and behaviors related to conduct disorder, hyperactivity, aggression, suicide, and depression and anxiety.
The researchers found that depression and anxiety scores “did not change significantly in children aged 10–11 years and 12–13 years.” They also found a “statistically significant decline in depression and anxiety in adolescents aged 14–15.” Meanwhile, “physical aggression and indirect aggression” declined in all three age groups. Suicidal behaviors also declined in key groups. Hyperactivity, though, increased significantly in the youngest age groups.
“With the exception of hyperactivity, the prevalence of symptoms of mental illness in Canadian children and adolescents has remained relatively stable from 1994/95 to 2008/09,” the authors wrote. “The distribution of scores on depression and anxiety, conduct and indirect aggression scales remained stable or showed small decreases over time for participants of all ages.”
So why have the rates of psychiatric medication use been increasing in children and youth, and why does it seem that the prevalence of mental illnesses is increasing? According to a Canadian Medical Association Journal press release, the authors blamed the media for creating a discrepancy between public perception and scientific actuality: “Popular media tends to perpetuate the idea that the prevalence of mental disorders is increasing.”
However, in the study abstract, the authors suggested different explanations “Conflicting reports of escalating rates of mental illness in Canada may be explained by differing methodologies between studies, an increase in treatment-seeking behaviour, or changes in diagnostic criteria or practices,” the authors wrote.
(Abstract) Time trends in symptoms of mental illness in children and adolescents in Canada (McMartin, Seanna E et al. Canadian Medical Association Journal. November 3, 2014. doi: 10.1503/cmaj.140064)
Most mental health disorders not increasing in children and youth: Large Canadian study (Canadian Medical Association Journal Press Release on EurekAlert, November 3, 2014)