Developmental variation in the context of marijuana initiation among adolescents.

A longitudinal sample of 3,454 secondary school students is used to examine the variations in the contexts of marijuana initiation which may be attributable to developmental changes during adolescence. Concepts representing the context of initiation include attachments to parents and peers, exposures to drug-related attitudes of parents and peers and behaviors of peers, and the decision-making process, which involves the weighing of expected costs and benefits of use. Measures representing these concepts are included in logistic regression models predicting initiation. Regression parameters are compared for students in the sixth, seventh, and eighth grades. Results show that only parental attachment measures influence initiation for the youngest group; a mix of parental and peer attachment and peer exposure measures affects initiation for the middle group; and only measures of peer attachment and exposure and of the relative importance of the costs of use predict initiation for the oldest group. The results suggest that developmental factors do influence the context of marijuana initiation.