This PA replaces PA-01-072. The National Institute of Mental Health (NIMH), National Institute of Neurological Disorders and Stroke (NINDS), National Institute on Drug Abuse (NIDA), and National Institute of Alcohol Abuse and Alcoholism (NIAAA) invite research grant applications through this Program Announcement (PA) to support research focused on determining the pathogenic mechanisms involved in Human Immunodeficiency Virus (HIV)-1 associated neurobehavioral and neurological dysfunction in domestic and international settings. The objective of this cooperative effort is to foster investigations that will provide the foundation for the rapid development of therapeutic interventions to prevent and treat the effects of HIV-1 on the central nervous system (CNS). Applications ranging from basic research to clinical diagnosis and treatment are of interest. Multidisciplinary research teams and collaborative alliances are encouraged but not required.