Platelet dense granule secretion and aggregation in adolescents with conduct disorder: Effects of marijuana use

Background: We had previously reported a decrease in agonist-induced platel et dense granule secretion in blood samples from male adolescents with and without Conduct Disorder (CD), In an augmented sample, we have now employed multivariate modeling to examine the simultaneons effects of Co and regula r monthly alcohol and marijuana use on bath the dense granule secretion and aggregation phases of agonist-induced platelet responses. Methods: Blood samples were obtained from adolescents with and without a CD diagnosis. Platelet dense granule secretion and aggregation responses to a variety of agonists were examined in the laboratory, Results: Significant multivariate interactions of CD status with regular ma rijuana use were, found for responses to collagen, ADP alone and ADP plus 0 .2 mu g. of serotonin. Responses in platelets from youth with CD, but witho ut regular marijuana use differed from other subjects. Multivariate main ef fects of marijuana use alone an platelet responses to arachidonic acid and ADP plus 1.0 mu g of serotonin were found. No effects of alcohol use were f ound. Conclusions: The results demonstrate an interaction between CD and the effe cts of chronic marijuana use for several agonists in this platelet model sy stem, and further support the possibility of a variation in signal transduc tion mechanisms in CD. (C) 1999 Society of Biological Psychiatry.