Poor prenatal nutrition has been associated with schizophrenia spectrum disorders in the Netherlands and China, and it has been suggested that perinatal and postnatal nutritional factors lead to the development of schizophrenia and the exhibition of schizotypal traits later in life. There appears to be no prior research on the existence of possible factors that may mediate the relationship between malnutrition and schizophrenia spectrum disorders or whether this association is a direct one. The authors tested the hypothesis that low IQ mediates the relationship between early childhood malnutrition and adult schizotypal personality.
Participants were drawn from a birth cohort of 1,795 boys and girls who were followed prospectively. Objective indicators of malnutrition (anemia and stunting) were assessed at age 3. Verbal and performance intelligence were assessed at age 11, and schizotypal personality was assessed at age 23.
Both stunting and anemia at age 3 were associated with low IQ at age 11. Low performance IQ at age 11 was associated with increased interpersonal and disorganized features of schizotypal personality at age 23. Poor performance IQ was found to mediate the relationship between poor nutrition at age 3 and interpersonal and disorganized features of schizotypy at age 23. Findings in female participants were replicated in male participants.
Given that poor nutrition is an alterable risk factor, these findings suggest that nutritional enhancements may improve brain functioning and possibly reduce some features of schizotypal personality disorder.