New publications
Season of birth influences depression levels in men, but has no significant effect on women
Last reviewed: 03.08.2025
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
Men born in the summer reported higher rates of depressive symptoms compared to men born in other seasons, according to a study conducted at Kwantlen Polytechnic University. Anxiety symptoms showed no association with birth season for either men or women.
Anxiety and depression remain among the most common mental disorders worldwide, with both conditions contributing to long-term disability, physical comorbidity, and significant economic losses. Mental health is influenced by a variety of factors across the lifespan, including housing, income, education, and age. Research on the impact of early life factors, particularly those related to seasonal environmental changes, is limited.
During pregnancy, exposure to temperature changes, maternal diet, seasonal infections, and changes in daylight hours can influence neurodevelopment. Season of birth has previously been linked to the risk of developing psychiatric disorders such as schizophrenia, bipolar disorder, and schizoaffective disorder. Studies of the relationship between season of birth and depression have shown mixed results, often without separating by gender.
The study, “Investigating the association between season of birth and symptoms of depression and anxiety in adults,” published in PLOS Mental Health, conducted a cross-sectional questionnaire to test the association of season of birth with symptoms of anxiety and depression in adults.
The study included 303 participants, the majority of whom were women (65%) and had an average age of 26 years. Data were collected online from January to March 2024 using a variety of recruitment methods in Vancouver, British Columbia.
Participants completed a 20-minute online questionnaire using the PHQ-9 and GAD-7 scales to assess the severity of depressive and anxiety symptoms. Birth months were grouped by meteorological season. A generalized linear mixed model was used for the analysis, with gender and birth season as fixed effects, and age, income, and the interaction of birth month and latitude as random effects.
Depression symptoms exceeded the threshold in 84% of respondents, anxiety symptoms in 66%. This high prevalence exceeds national estimates and may reflect the young, predominantly student winter sample.
Mean depression scores were above the threshold in most demographic groups. Men born in summer had slightly higher scores than men born in other seasons. For women, no significant interaction with season was found, although mean scores were slightly higher for those born in winter and spring. Anxiety scores were not related to season of birth or interacted with gender.
In women, no association was found between season of birth and symptoms. No significant association was found between season of birth and anxiety symptoms in either sex.
The researchers concluded that season of birth may serve as a marker of early environmental exposures that influence depression risk in a gender-specific manner. Further studies should examine biological mechanisms related to photoperiod, maternal nutrition, and immune activation during pregnancy.
Limitations of the study include the cross-sectional design, winter data collection period, lack of measurements of abiotic effects, and predominantly student sample, which limit the ability to establish causal relationships and generalize the results.