ERBB4 and schizophrenia: Increased ERBB4 activity leads to an excitation/inhibition imbalance in schizophrenic patients,30,31 and antagonizing ERBB4 activity using spironolactone improved schizophrenia relevant phenotypes including cognition in a Nrg1 transgenic mouse model,32 prompting also a clinical trial with spironolactone as adjuvant to antipsychotic medication, i.e., co-administering spironolactone with an established antipsychotic, e.g., risperidone or aripiprazole.78