Letter to the Editor: Association between smoking and psychosis may be mediated by maternal smoking during pregnancy

Smoking during pregnancy has been shown to be a risk factor for the subsequent development of schizophrenia (Niemel et al., 2016). Since similar effects are seen with maternal malnutrition and infections during pregnancy (Xu et al., 2009; Khandaker et al., 2013), it seems reasonable to conclude that a broad range of insults during pregnancy, including maternal smoking, may impact on neurodevelopment in a way, which increases susceptibility to subsequent psychosis. Smoking behaviour is familial, with both genetic and cultural effects (Bares et al., 2016). [...]research subjects who currently smoke are more likely to have mothers who smoked during pregnancy and this would be expected to increase their risk of schizophrenia and/or psychotic experiences. [...]the mechanism I propose does not explain the observed association between smoking and schizophrenia in discordant monozygotic twins (Lyons et al., 2002), nor the correlation in individuals between smoking behaviour and psychotic experiences over time (Taylor et al., 2014).