Season of birth shows slight association with depression in men but not women

Males born in summer months reported higher depression symptom scores than males born during other seasons, according to a study from Kwantlen Polytechnic University. Anxiety symptoms showed no association with season of birth for either sex.

Anxiety and depression remain among the most common mental disorders worldwide, with both conditions contributing to long-term disability, physical comorbidities, and substantial economic losses. A range of factors shape mental health across the lifespan, including housing, income, education, and age. Research into early-life exposures remains limited, particularly exposures shaped by environmental seasonality.

During gestation, exposure to temperature shifts, maternal diet, seasonal infections, and variation in daylight may influence neurodevelopment. Birth season has previously been associated with risk for psychiatric conditions including schizophrenia, bipolar disorder, and schizoaffective disorder. Studies examining birth season and depression have produced mixed results, often without stratifying by sex.

In the study, “Investigating the association between season of birth and symptoms of depression and anxiety in adults,” published in PLOS Mental Health, researchers designed a cross-sectional survey to test whether season of birth is associated with adult symptoms of anxiety or depression.

Participants (n=303) were primarily women (65%), with a mean age of 26 years. Data were collected online between January and March 2024, using recruitment strategies across Vancouver, British Columbia.

Participants completed a 20-minute online questionnaire that included the PHQ-9 and GAD-7 scales to assess depression and anxiety symptom severity. Birth months were grouped by meteorological season. Researchers used a generalized linear mixed model to test the relationship between season of birth and symptom scores. Sex and season of birth were fixed effects. Age, income, and the interaction between month of birth and latitude were included as random effects.

Depression symptoms met the threshold in 84% of respondents, and anxiety symptoms in 66%. Such prevalence exceeds national estimates and may reflect the young, student-heavy winter sample.

Mean depression scores exceeded the threshold across most demographic groups. Summer-born men recorded marginally higher scores than men born in other seasons. Women showed no significant association with season, although mean scores were slightly higher for winter and spring-born participants. Anxiety scores showed no relationship with season or sex interaction.

No association was observed for females. No significant association was found between season of birth and anxiety symptoms in either sex.

Researchers concluded that season of birth may act as a proxy for early environmental exposures influencing depression risk in a sex-specific manner. Further work should probe biological pathways involving photoperiod, maternal nutrition, and immune activation during gestation.

Study limitations include its cross-sectional design, winter data-collection window, absence of abiotic exposure measures, and a student-heavy convenience sample, all of which constrain causal inference and generalizability.

© 2025 Science X Network

Males born in summer months reported higher depression symptom scores than males born during other seasons, according to a study from Kwantlen Polytechnic University. Anxiety symptoms showed no association with season of birth for either sex.

Anxiety and depression remain among the most common mental disorders worldwide, with both conditions contributing to long-term disability, physical comorbidities, and substantial economic losses. A range of factors shape mental health across the lifespan, including housing, income, education, and age. Research into early-life exposures remains limited, particularly exposures shaped by environmental seasonality.

During gestation, exposure to temperature shifts, maternal diet, seasonal infections, and variation in daylight may influence neurodevelopment. Birth season has previously been associated with risk for psychiatric conditions including schizophrenia, bipolar disorder, and schizoaffective disorder. Studies examining birth season and depression have produced mixed results, often without stratifying by sex.

In the study, “Investigating the association between season of birth and symptoms of depression and anxiety in adults,” published in PLOS Mental Health, researchers designed a cross-sectional survey to test whether season of birth is associated with adult symptoms of anxiety or depression.

Participants (n=303) were primarily women (65%), with a mean age of 26 years. Data were collected online between January and March 2024, using recruitment strategies across Vancouver, British Columbia.

Participants completed a 20-minute online questionnaire that included the PHQ-9 and GAD-7 scales to assess depression and anxiety symptom severity. Birth months were grouped by meteorological season. Researchers used a generalized linear mixed model to test the relationship between season of birth and symptom scores. Sex and season of birth were fixed effects. Age, income, and the interaction between month of birth and latitude were included as random effects.

Depression symptoms met the threshold in 84% of respondents, and anxiety symptoms in 66%. Such prevalence exceeds national estimates and may reflect the young, student-heavy winter sample.

Mean depression scores exceeded the threshold across most demographic groups. Summer-born men recorded marginally higher scores than men born in other seasons. Women showed no significant association with season, although mean scores were slightly higher for winter and spring-born participants. Anxiety scores showed no relationship with season or sex interaction.

No association was observed for females. No significant association was found between season of birth and anxiety symptoms in either sex.

Researchers concluded that season of birth may act as a proxy for early environmental exposures influencing depression risk in a sex-specific manner. Further work should probe biological pathways involving photoperiod, maternal nutrition, and immune activation during gestation.

Study limitations include its cross-sectional design, winter data-collection window, absence of abiotic exposure measures, and a student-heavy convenience sample, all of which constrain causal inference and generalizability.

© 2025 Science X Network