Season of Birth in Schizophrenia in the Mexico City Area: Comparison with General Population

The role of latitude and infections in the month-of-birth effect linked to schizophrenia

“… Karlsson et al, 2019 Population-based Sweden All births: 1940–1997 30684 Schizophrenia Monthly 8 Excess winter (December) schizophrenia births. Munoz-Delgado et al, 2003 Single-centre Mexico Schizophrenia diagnosis: 1913–1989 General Population Births: 1991–2001 2288 Schizophrenia Monthly 5 Non-significant increment in Autumn/Winter months. Torrey et al, 1977 Population-based USA All births: 1920–1955 53584 Schizophrenia Monthly 7 Higher schizophrenia births seen from December to May (peak March/April).…”

“…Accordingly, it was hypothesised that sunlight and more specifically vitamin D levels could play an important role in the disease, but subsequent genetic epidemiology studies have not supported this theory ( Taylor et al, 2016 ). Since then, several new studies investigating the month-of-birth effect in schizophrenia have emerged ( Carrion-Baralt et al, 2004 ; Disanto et al, 2012 ; Cheng et al, 2013 ; Karlsson et al, 2019 ; Munoz-Delgado et al, 2003 ; Mino and Oshima, 2006 ). Some of these studies were carried out in low latitude countries where sunlight does not vary substantially throughout the year but the link between winter birth and risk of schizophrenia has persisted in these countries ( Carrion-Baralt et al, 2004 ; Munoz-Delgado et al, 2003 ).…”

“…Since then, several new studies investigating the month-of-birth effect in schizophrenia have emerged ( Carrion-Baralt et al, 2004 ; Disanto et al, 2012 ; Cheng et al, 2013 ; Karlsson et al, 2019 ; Munoz-Delgado et al, 2003 ; Mino and Oshima, 2006 ). Some of these studies were carried out in low latitude countries where sunlight does not vary substantially throughout the year but the link between winter birth and risk of schizophrenia has persisted in these countries ( Carrion-Baralt et al, 2004 ; Munoz-Delgado et al, 2003 ). This in turn has brought doubt to the relevance of latitude to the month-of-birth effect in schizophrenia.…”

Month of birth and mental disorders: A population‐based study and validation using global meta‐analysis

“…In a further systematic review, we identified 10 disorders (intellectual disability, ASD, ADHD, schizophrenia, BID, MDD, AUD, Alzheimer's disease, anorexia nervosa, and bulimia nervosa) in 51 articles conducted in 25 countries involving 1 539 811 patients 1,3,5,6,27‐73 . The meta‐analytic results of our findings and included studies are summarized in Table 2.…”

“…In a further systematic review, we identified 10 disorders (intellectual disability, ASD, ADHD, schizophrenia, BID, MDD, AUD, Alzheimer's disease, anorexia nervosa, and bulimia nervosa) in 51 articles conducted in 25 countries involving 1 539 811 patients. 1 , 3 , 5 , 6 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , …”