A method for the treatment of a patient suffering from an endogenous behavioral disorder in order to ameliorate at least some behavioral aspects of the disorder, the method comprising administering to the patient a therapeutic quantity of at least one ACE inhibitor. Behavioral aspects of endogenous disorders such as attention deficit disorder (ADD), obsessive-compulsive disorder (OCD), oppositional explosive defiant disorder (OEDD), anxiety and panic disorders (APD) and temper, rage and outburst behavior disorder (TROBD), are ameliorated by a regimen of ACE inhibitor.