The relation between ego defense mechanisms, diagnoses, & suicidality was investigated among 200 adolescent psychiatric patients who were divided into 3 groups: suicide attempters, suicidal ideators & nonsuicidal patients. Using the Defense Mechanisms Inventory, suicidal adolescents scored high on the defense of turning-against-self & lower on reversal. Turning-against-self remained significantly associated with suicide attempts even when diagnosis was controlled for. (64 refs.)