Birth during autumn is a risk for adolescent self-mutilative behavior

Area of Science:

• Psychiatry
• Developmental Psychology
• Epidemiology

Background:

• A seasonal birth tendency is linked to various psychiatric disorders and suicidal behaviors.
• Investigating the season of birth association with self-mutilative behavior (SMB) in adolescents is crucial.

Purpose of the Study:

• To examine the relationship between season of birth and self-mutilative behavior (SMB) in adolescent psychiatric inpatients.
• To identify potential seasonal predispositions to self-harm in a vulnerable population.

Main Methods:

• A cohort of 508 adolescents (aged 12-17) admitted to Oulu University Hospital, Finland, was studied.
• Birth months were categorized into four seasons: spring, summer, autumn, and winter.
• Self-mutilative behavior (SMB) was assessed using the K-SADS-PL interview; logistic regression controlled for age, prior suicide attempts, and psychiatric diagnoses.

Main Results:

• The birth month distribution for adolescents with SMB significantly differed from the general population.
• A notable association between season of birth and SMB was observed in adolescent girls, but not in boys.
• Girls born in autumn had a significantly higher likelihood of SMB (adjusted OR 2.9) compared to those born in winter.

Conclusions:

• Autumn birth may increase girls' predisposition to SMB, potentially through serotonergic or other neurotransmitter system dysregulation.
• Seasonal variations in parental mood and early care could also contribute to this observed association.
• These findings highlight the importance of considering seasonal influences in understanding adolescent self-harm.