HTR1A and schizophrenia: Overall, meta-analysis from Selvaraj and colleagues35 found that the pooled results were in favour of a significant increase in 5-HT1A receptors in the prefrontal cortex of patients with schizophrenia compared to healthy controls, with an effect size of 0.60 (CI: 0.17–1.03, p = 0.007)35.