Compared with adults, young people may be more vulnerable to seasonal symptoms of depression, which may be particularly pronounced in countries that experience pronounced seasonal changes, according to research published in Journal of Affective Disorders.
Researchers conducted a cross-sectional analysis of data from the 2015 and 2016 Canadian Community Health Survey to evaluate the seasonal pattern of depressive symptoms linked to seasonal affective disorder (SAD). Respondents were evaluated via the Patient Health Questionnaire-9.
Investigators analyzed data from 53,000 respondents across 8 provinces and territories. Results were stratified by age into 2 groups: adults aged ≥25 years (n=45,000) and youths aged 12 to 24 years (n=8000). As expected, adults had higher levels of education and employment rates, and more young people reported that they were students (69.59%).
Within the youth group, all evaluated symptoms demonstrated “significant” seasonal trends, except the questionnaire item on suicidality and self-harm. Comparatively, the adult group demonstrated “distinct” results; only questions regarding sleep habits and appetite were associated with significant seasonal variation. There was “a significant interaction of age for items that showed a seasonal pattern in youth but not adults.” Answers to the questionnaire item “feeling bad about oneself” represented a nonsignificant exception that tended toward significance.
Results for items related to sleeping, feeling bad about oneself, and trouble concentrating were stratified by month. These results indicated that in both groups, there is similar seasonal variation in problems sleeping. A strong contrast in seasonal variation was noted between the youth and adult groups regarding feeling bad about oneself, feeling like a failure or let down, and trouble concentrating. Youth scores fluctuated seasonally, but adult scores trended toward a flat line throughout the year.
Study limitations included general limitations associated with cross-sectional data, including an inability to assess the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition concept of SAD, which would require longitudinal data, as well as information about the treatment status of respondents. Researchers were unable to control for student status, and therefore unable to determine which respondents were on vacation — which might affect responses — when they answered the questionnaire.
“Some clinicians have doubts about the seriousness or even existence of seasonal depression,” the researchers concluded. “Our results demonstrate that youth may have increased vulnerability to secondary symptoms, potentially making them more susceptible to developing SAD.”
They added, “The strong seasonal patterns of self-esteem and concentration seen in youth are an important public health concern since they coincide with the school year and could affect academic abilities and social relationships.”
Lukmanji A, Williams JVA, Bulloch AGM, Patten SB. Seasonal variation in specific depressive symptoms: a population based study. J Affect Dis. 2019;261:153-159.