The military has failed to correct the wrongful discharges of thousands of Vietnam veterans suffering from post-traumatic stress disorder, an advocacy group says in a federal lawsuit.

Vietnam Veterans of America on Monday joined a proposed class action lawsuit in Hartford against the Army, Navy and Air Force. The lawsuit, first filed last year by a veteran, says the Vietnam veterans suffered PTSD before the condition was recognized and were discharged under other-than-honorable conditions that made them ineligible for disability compensation and other benefits.