WNT1 and attention deficit-hyperactivity disorder: Both upstream and downstream elements of the canonical Wnt pathway have been associated with different psychiatric conditions: WNT1 and WNT2 with autism spectrum disorder (ASD), WNT2B with bipolar disorder (BD), WNT7A with ASD and BD, WNT7B with schizophrenia (SCZ), LRP5 with SCZ, attention‐deficit/hyperactivity disorder (ADHD) and major depression (MD), and LRP6 with ADHD 15, 16, 17, 18, 19, 20, 21.