From the Editor

Seasonality of birth and psychiatric illness

Current Psychiatry. 2019 January;18(1):4,6,8

References

1. Torrey EF, Miller J, Rawlings R, et al. Seasonality of births in schizophrenia and bipolar disorder: a review of the literature. Schizophr Res. 1997;28(1):1-38.
2. McGrath J, Welham J, Pemberton M. Month of birth, hemisphere of birth and schizophrenia. Br J Psychiatry. 1995;167(6):783-785.
3. Doblhammer G, Vaupel JW. Lifespan depends on month of birth. Proc Natl Acad Sci U S A. 2001;98(5):2934-2939.
4. Mandel Y, Grotto I, El-Yaniv R, et al. Season of birth, natural light, and myopia. Ophthalmology. 2008;115(4):686-692.
5. Lloyd PC, May L, Hoffman D, et al. The effect of birth month on the risk of respiratory syncytial virus hospitalization in the first year of life in the United States. Pediatr Infect Dis J. 2014;33(6):e135-e140.
6. Gazala E, Ron-Feldman V, Alterman M, et al. The association between birth season and future development of childhood asthma. Pediatr Pulmonol. 2006;41(12):1125-1128.
7. Hao Y, Yan L, Ke E, et al. Birth in winter can reduce the risk of lung cancer: A retrospective study of the birth season of patients with lung cancer in Beijing area, China. Chronobiol Int. 2017;34(4):511-518.
8. Francis NK, Curtis NJ, Noble E, et al. Is month of birth a risk factor for colorectal cancer? Gastroenterol Res Pract. 2017;2017:5423765. doi: 10.1155/2017/5423765.
9. Si J, Yu C, Guo Y, et al; China Kadoorie Biobank Collaborative Group. Season of birth and the risk of type 2 diabetes in adulthood: a prospective cohort study of 0.5 million Chinese adults. Diabetologia. 2017;60(5):836-842.
10. Sohn K. The influence of birth season on mortality in the United States. Am J Hum Biol. 2016;28(5):662-670.
11. Crump C, Sundquist J, Sieh W, et al. Season of birth and risk of Hodgkin and non-Hodgkin lymphoma. Int J Cancer. 2014;135(11):2735-2739.
12. Stoupel E, Abramson E, Fenig E. Birth month of patients with malignant neoplasms: links to longevity? J Basic Clin Physiol Pharmacol. 2012;23(2):57-60.
13. Rothwell PM, Gutnikov SA, McKinney PA, et al. Seasonality of birth in children with diabetes in Europe: multicentre cohort study. European Diabetes Study Group. BMJ. 1999;319(7214):887-888.
14. Yuen J, Ekbom A, Trichopoulos D, et al. Season of birth and breast cancer risk in Sweden. Br J Cancer. 1994;70(3):564-568.
15. Aalberse RC, Nieuwenhuys EJ, Hey M, et al. ‘Horoscope effect’ not only for seasonal but also for non-seasonal allergens. Clin Exp Allergy. 1992;22(11):1003-1006.
16. Kirkpatrick B, Messias E, LaPorte D. Schizoid-like features and season of birth in a nonpatient sample. Schizophr Res. 2008;103:151-155.
17. Zerbo O, Iosif AM, Delwiche L, et al. Month of conception and risk of autism. Epidemiology. 2011;22(4):469-475.
18. Hebert KJ, Miller LL, Joinson CJ. Association of autistic spectrum disorder with season of birth and conception in a UK cohort. Autism Res. 2010;3(4):185-190.
19. Landau EC, Cicchetti DV, Klin A, et al. Season of birth in autism: a fiction revisited. J Autism Dev Disord. 1999;29(5):385-393.
20. Parker G, Neilson M. Mental disorder and season of birth--a southern hemisphere study. Br J Psychiatry. 1976;129:355-361.
21. Sit D, Seltman H, Wisner KL. Seasonal effects on depression risk and suicidal symptoms in postpartum women. Depress Anxiety. 2011;28(5):400-405.
22. Chan JE, Samaranayaka A, Paterson H. Seasonal and gestational variation in perinatal depression in a prospective cohort in New Zealand. Aust N Z J Obstet Gynaecol. 2018. [Epub ahead of print]. doi: 10.1111/ajo.12912.
23. Grootendorst-van Mil NH, Steegers-Theunissen RP, Hofman A, et al. Brighter children? The association between seasonality of birth and child IQ in a population-based birth cohort. BMJ Open. 2017;7(2):e012406. doi: 10.1136/bmjopen-2016-012406.
24. Salib E, Cortina-Borja M. Effect of month of birth on the risk of suicide. Br J Psychiatry. 2006;188:416-422.
25. Salib E, Cortina-Borja M. An association between month of birth and method of suicide. Int J Psychiatry Clin Pract. 2010;14(1):8-17.
26. Brewerton TD, Dansky BS, O’Neil PM, et al. Seasonal patterns of birth for subjects with bulimia nervosa, binge eating, and purging: results from the National Women’s Study. Int J Eat Disord. 2012;45(1):131-134.
27. Asano R, Tsuchiya KJ, Harada T, et al; for Hamamatsu Birth Cohort (HBC) Study Team. Season of birth predicts emotional and behavioral regulation in 18-month-old infants: Hamamatsu birth cohort for mothers and children (HBC Study). Front Public Health. 2016;4:152.
28. Luykx JJ, Bakker SC, Lentjes E, et al. Season of sampling and season of birth influence serotonin metabolite levels in human cerebrospinal fluid. PLoS One. 2012;7(2):e30497. doi: 10.1371/journal.pone.0030497.
29. Videbech P, Nielsen J. Chromosome abnormalities and season of birth. Hum Genet. 1984;65(3):221-231.
30. Vézina H, Houde L, Charbonneau H, et al. Season of birth and Alzheimer’s disease: a population-based study in Saguenay-Lac-St-Jean/Québec (IMAGE Project). Psychol Med. 1996;26(1):143-149.

“To every thing there is a season, and a time to every purpose under the heaven.”

— Ecclesiastes

The month of birth is not just relevant to one’s astrological sign. It may have medical consequences. An impressive number of published studies have found that the month and season of birth may be related to a higher risk of various medical and psychiatric disorders.

For decades, it has been reported in more than 250 studies¹ that a disproportionate number of individuals with schizophrenia are born during the winter months (January/February/March in the Northern Hemisphere and July/August/September in the Southern Hemisphere). This seasonal pattern was eventually linked to the lack of sunlight during winter months and a deficiency of vitamin D, a hormone that is critical for normal brain development. Recent studies have reported that very low serum levels of vitamin D during pregnancy significantly increase the risk of schizophrenia in offspring.²

But the plot thickens. Numerous studies over the past 20 to 30 years have reported an association between month or season of birth with sundry general medical and psychiatric conditions. Even longevity has been reported to vary with season of birth, with a longer life span for people born in autumn (October to December), compared with those born in spring (April to June).³ Of note, a longer life span for an individual born in autumn has been attributed to a higher birth weight during that season compared with those born in other seasons. In addition, the shorter life span of those with spring births has been attributed to factors during fetal life that increase the susceptibility to disease later in life (after age 50).

The following studies have reported an association between month/season of birth and general medical disorders:

Higher rate of myopia for summer births⁴
Tenfold higher risk of respiratory syntactical virus in babies born in January compared with October, and a 2 to 3 times higher risk of hospitalization⁵
Higher rates of asthma during childhood for March and April births⁶
Lower rate of lung cancer for winter births compared with all other seasons⁷
An excess of colon and rectal cancer for people born in September, and the lowest rate for spring births⁸
Lowest diabetes risk for summer births⁹
For males: Cardiac mortality is 11% less likely for 4th-quarter births compared with 1st-quarter births. For females: Cancer mortality is lowest in 3rd-quarter vs 1st-quarter births¹⁰
The peak risk for both Hodgkin and non-Hodgkin lymphoma is for April births compared with other months¹¹
A strong trend for malignant neoplasm in males was reported for births during the 1st trimester of the year (January through April) compared with the rest of the year¹²
Higher rate of spring births among patients who have insulin-dependent diabetes¹³
Breast cancer is 5% higher for June births compared with December births¹⁴
Higher risk of developing an allergy later in life for those born approximately 3 months before the main allergy season.¹⁵

The above studies may imply that birth seasonality is medical destiny. However, most such reports need further replication, or may be due to chance findings in various databases. However, they are worth considering as hypothesis-generating signals.

Continue to: And now for the risk of psychiatric disorders...

Seasonality of birth and psychiatric illness

References

Pages

Recommended Reading