The objective of this study was to identify seasonal variations in mental health–related hospitalizations among children, adolescents, and adults using administrative health data. Hospital admission records from January 2004 to March, 2014 were sourced from the New Brunswick Discharge Abstract Database. Seasonality was measured using a cosinor model to estimate the phase, amplitude, and peak of seasonal variations in psychiatric admissions over the 12-month period from January through December. A general linear model using a Poisson distribution was used to calculate rate ratios that measured the significance of monthly variations in psychiatric admissions. We adjusted for the average number of days per month and provincial population counts using offsets in both models. Between 2004 and 2014, there were 57,730 mental health–related hospital admissions by 41,690 patients. Psychiatric admissions by children and adolescents (aged 3–19 years) increased from 44 admissions per 100,000 in 2004 to 51 admissions per 100,000 in 2014. Rates of psychiatric admissions among children, adolescents, and adults exhibited seasonality confirmed through the detection of a statistically significant sinusoidal pattern (p < .025). The highest rates of child and adolescent admissions were in February (phase = 2, amplitude = 4.4), whereas adult admissions to the hospital peaked in early May (phase = 5.3, amplitude = 9.7). These findings lend support to existing efforts to identify the complex array of individual, family, community, and environmental factors that influence the likelihood of acute care utilization for management of psychiatric disorders.

Slaunwhite, A. K., Ronis, S. T., Peters, P. A., & Miller, D. (2018). Seasonal variations in psychiatric admissions to hospital. Canadian Psychology/Psychologie Canadienne, doi: