This edition, the eighth in the series of annual reports, is a nontechnical summary of recent developments in marihuana research with a summary of research through the end of 1979 concerning possible health implications, which cannot be reported with great certainty because of the brief duration of the American marihuana experience. Areas of discussion include: (1) the possible effects on reproduction and pulmonary function; (2) the nature and extent of marihuana use and its chemistry; (3) acute effects on memory and intellectual tasks including driving; (4) long-term effects; (5) psychopathological effects; (6) therapeutic uses in treating cancer chemo-therapy patients; (7) the effects of marihuana in combination with alcohol and other drugs; and (8) the hazards of marihuana as a recreational drug. Future research directions and a references section are also included. (JAC)