Notably, both PACAP peptide and its receptor, PACAP 1 receptor (PAC1R), exhibit elevated expression in brain regions associated with stress modulation responses and anxiety-related behaviors, as well as in regions involved in substance use disorder (SUD), including the hypothalamus, thalamus, bed nucleus of the stria terminalis (BNST), nucleus accumbens, parabrachial nucleus (PBN), striatum, and hippocampus (Vaudry et al., 2009; Rajbhandari et al., 2023; Boucher et al., 2021; Jaramillo et al., 2021; Lutfy and Shankar, 2019; Curtis et al., 2023). The gene discussed is ADCYAP1R1; the disease is Anxiety.