Chunk #24 — FROM GENE DISCOVERY TO POLYGENICITY: POLYGENIC AND WITHIN‐FAMILY APPROACHES TO ILLUMINATE MECHANISMS OF GENETIC RISK — Polygenic risk in a longitudinal framework
Several COGA publications have leveraged the longitudinal design of the Prospective Sample of COGA, which includes individuals from COGA case and comparison families who were recruited between ages 12 and 22 and invited back for biennial assessments (see, also 2. Sample and Clinical Data and 3. Brain Function). For example, one recent paper 127 leveraged the longitudinal nature of the COGA prospective sample to generate latent trajectories of cannabis use across ages 12–30 years and explored how perceived peer cannabis use and polygenic liability for cannabis use were independently and jointly associated with these trajectories of use. Three trajectory classes were identified, generally representing no/low cannabis use (N = 844), moderate use (N = 137), and high use (N = 186). This study showed that greater polygenic predisposition to cannabis use was associated with greater perceived peer cannabis use and belonging to a higher cannabis use trajectory class. Importantly, this paper also showed that peer cannabis use and polygenic liability to cannabis use were independently associated with trajectory class membership. This was one of the first studies to document how
