This volume, intended for both professionals and the public, contains the ten papers and the ten edited transcripts of discussions from the National Institute on Drug Abuse workgroup. Each of the first five chapters presents two of the papers and discussion highlights selected by the authors. The papers included are: "Cannabis: Effects Upon Adolescent Motivation," by Sidney Cohen; "Incidence and Characteristics of Amotivational Syndrome, Including Associated Findings, Among Chronic Marijuana Users," by James Halikas, And Others; "Psychological Effects of Cannabis in Adolescence," by Doris H. Milman; "Some Clinical Comments on Chronic Marijuana Use in Adolescent Psychiatric Patients," by John E. Meeks; "The Relationship of Moderate Marijuana Use and Adolescent Behavior," by Donald Ian Macdonald; "The Effects of Marijuana on the Young," by Harold M. Voth; "Clinical Perspectives on the Toxicity of Marijuana: 1967-1981," by David E. Smith and Richard B. Seymour; "A Family Approach to Marijuana Use," by H. Charles Fishman; "Marijuana Abuse by Children and Teenagers: A Pediatrician's View," by Ingrid L. Lantner; and "Marijuana in the School: Clinical Observations and Needs," by Robert G. Niven. Chapter 6 contains selections from the workgroup's final discussions. Chapter 7 presents the summary and conclusions, discussing the idea of the family as the central focus in both prevention and management of marijuana-induced emotional and cognitive disorders in children; the necessity of raising the consciousness of health care professionals; the need for individual, familial, and national programs for prevention of marijuana use by adolescents, and the need for further, controlled clinical research into the nature of marijuana-induced brain syndromes. (AG)