Court decisions stressing the rights of mental patients have necessitated a radical revision in the management of behavioral treatment programs. The client's rights to the least intrusive procedures to achieve treatment goals have become important in case law. Factors which identify intrusiveness include: (1) the extent to which the "new mental state is foreign or unnatural" to the patient; (2) the extent to which the effects of therapy are reversible; (3) the rapidity with which effects occur; (4) the duration of change; (5) the extent of bodily invasion; (6) the nature of side effects; and (7) the extent to which an uncooperative patient can avoid the effects of treatment. A prominent attorney has ranked treatments from least to most intrusive: milieu therapy, psychotherapy, drug therapy, behavioral modification, aversion therapy, ECT, brain stimulation, lobotomy, and stereotactic psychosurgery. The psychological treatments of milieu therapy, psychotherapy, behavior modification, and aversion therapy vary widely and cannot reasonably be ranked in such a manner. Psychologists must be prepared to answer questions about their therapies, to enlighten legal professionals about the distinctions among therapies, and to encourage the courts to specify particular therapy procedures for involuntary clients. (Author/NRB)