Does Parents' Age at First Birth Moderate Intergenerational Continuity in Early-Onset Cannabis Use?

The aims of this brief report were to examine the extent to which early onset of cannabis use by parents and their children, and intergenerational continuity in early-onset cannabis use by parents and children, differ as a function of parent age at birth of first child.

A total of 795 parent-child dyads (57% male parents and 49% male children) were compiled from three intergenerational studies: Oregon Youth Study-Three Generational Study (OYS-3GS), Rochester Youth Development Study and Rochester Intergenerational Study (RYDS-RIGS), and Seattle Social Development Project-The Intergenerational Project (SSDP-TIP). Parents and children identified as non-Hispanic White (29% and 22%, respectively), Black (55% and 47%), and Hispanic (8% and 11%). Early-onset cannabis use was defined as initiation at or before age 15. Time-varying effect models were fit to examine the research questions.

Among parents, earlier initiation of cannabis use was associated with an earlier entry into parenthood. Moreover, parents' later age at first birth was predictive of a lower prevalence of early-onset cannabis use among their children. Last, regarding intergenerational continuity, parental early onset of cannabis use increased the likelihood of child early-onset use, but only among older parents (i.e., later age at first birth).

We provide a nuanced examination of the associations between parental and child early-onset cannabis use as a function of parents' age at first birth and describe a novel approach to incorporating parent's age at first birth into models of intergenerational continuity.