Two papers on the medical aspects of AIDS cover the natural history of infection with the human immunodeficiency virus (HIV) and the questions a doctor may be asked by patients who fear they may have been exposed to HIV or have AIDS. Part II contains seven papers on AIDS epidemiology and drug abuse. These papers examine more intensively than Part I the spread of the AIDS virus among various risk groups, particularly among intravenous (IV) drug abusers. Among the topics covered are the epidemiology and risk factors for transmission, the epidemiology of the HIV, the epidemiology of AIDS among IV drug abusers. Part III contains four papers that examine mental health issues that stem not only from the neurological complications of AIDS, but also from the reactions to AIDS patients by their families and society. Among the subjects considered are the psychological results of unemployment, loss of health insurance, and alienation from friends and families; ethical issues in the mental health care of AIDS patients at each stage of the illness; and findings in psychiatric consultations with AIDS patients. Six papers focus on the development of educational programs to help IV drug abusers learn to lessen their high-risk behaviors. Three papers on the social and ethical implications of AIDS consider the social dimension of AIDS legal and ethical issues associated with the illness, and legal and public policy options toward drug-independent populations. Glossary, subject index, and 275-item bibliography