However, levels of PACAP have been also associated with other cognitive diseases such as schizophrenia (Ago et al. 2018; Hashimoto et al. 2007; Vacic et al. 2011), with recent evidence correlating increased PACAP expression with schizophrenia related to suicide (Slabe et al. 2023), which indicates that therapeutic initiatives in PD should carefully monitor potential side effects. The gene discussed is ADCYAP1; the disease is schizophrenia.