ATP6V1B2 and depressive symptom measurement: Importantly, a single nucleotide polymorphism (SNP) within ATP6V1B2, rs1106634, has exhibited a suggestive p-value in a meta-analysis in schizophrenia and bipolar disorder (p = 3.97 × 10−6) and has been associated with lifetime risk of depression (p < 0.001) in a recent study [51–53].