EGFR and major depressive disorder: Since dysfunctions in NRGs/ErbB signaling have been linked to different neurological and psychiatric disorders, including schizophrenia, bipolar disorder, autism spectrum disorders, genetic intellectual disabilities, AD, major depressive disorder, PD, and addiction [23,46,136,137,138,139,141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159], intense research efforts should be aimed at deciphering NRGs-dependent mechanisms causing pathological defects, as this might have noticeable implications on the understanding and treatment of different serious brain diseases.