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

Anthropometry in antipsychotic-naïve first-episode psychosis patients: An exploratory approach to the role of environmental early life events in two independent samples

“…In our opinion reduced anthropometric values reflect a differential impact in the fetal development of patients who later will develop psychosis, being more severe than the general population and so reflecting different growth patterns in adulthood. Recent meta-analysis confirmed that maternal infection during pregnancy increases the risk of psychosis (Saatci et al, 2021) while no relation was described with latitude or day-light (Saatci et al, 2022). In our sample both cohorts come from similar latitude.…”

“…Indeed, season and month of birth have been correlated with later anthropometric features in childhood in the general population (Hemati et al, 2021). Environmental factors such as temperature (Cheng et al, 2008), sunlight exposition-vitamin D (Adamson et al, 2017) or infections (Saatci et al, 2022) have been proposed to underlie the association with winter birth, either in northern or southern hemisphere (McGrath and Welham, 1999). Early life stressful events also impact the fetus's growth pattern, slowing growth and reducing its body size from birth to adulthood (Wang et al, 2010).…”

Six Decades of Dopamine Hypothesis: Is Aryl Hydrocarbon Receptor the New D2?

“…Translocation of Hafnei alvei, Pseudomonas aeruginosa, Morganella morganii, Pseudomonas putida, and Klebsiella pneumoniae [12][13][14] Comorbidity with IBD AhR/STAT3/IL-22-regulated intestinal permeability and microbiota translocation [11,15,16] Comorbidity with HIV AhR/STAT3/IL22-regulateted gut barrier permeability [12,17,18] Poor insight (anosognosia) IC activation by gut Prevotella and Bacteroides abundance [19][20][21][22][23][24][25] Higher prevalence in urban areas Pollutants are AhR ligands associated with SCZ and are more prevalent in industrialized countries and urban areas [26][27][28][29][30][31][32][33][34] Increasing prevalence with the distance from the equator Sunlight-driven vitamin D derivatives and tryptophan light metabolites are AhR ligands [35][36][37][38][39] Autoantibodies Gut microbes express molecules, including GABA and NMDA, which can elicit formation of antibodies upon translocation [40][41][42] Aryl hydrocarbon receptor (AhR), a cytosolic transcription factor, initially described as the dioxin receptor, responds to numerous exogenous and endogenous ligands, inducing both immune tolerance of gut microbes as well as their prompt elimination upon translocation into host tissues [43,44]. In the cytosol, AhR is bound by two heat shock protein 90 (HSP90) chaperones, molecules recently identified as both SCZ and Parkinson's disease (PD) targets [45][46]…”

“…The most studied sunlight-dependent AhR ligands include vitamin D3, and tryptophan photo-metabolites, such as 6-formylindolo [3,2-b]carbazole (FICZ), play a key role in latitude-dependent SCZ prevalence [35,202,203]. Upon vitamin D3/AhR binding, the receptor/ligand complex is shuttled into the nucleus where the transcription of multiple genes is initiated or suppressed [36][37][38]. In addition, FICZ upregulates IL22, protecting the gut barrier and BBB, likely explaining the lower prevalence of SCZ in warm climates [35,37].…”

Season of birth and schizotypy in a sample of undergraduate students

“…One such factor that has been associated with risk for schizophrenia is season of birth (SoB) [8][9][10]. Indeed, birth in winter has been associated with a slight increase in the risk for developing schizophrenia (RR = 1.04-1.07).…”