Among the analytic sample, the GRS predicted number of cigarettes smoked per day (risk ratio=1.76 (0.89, 3.49)) and accounted for ∼3% of the overall variance in this trait. Traumatic events, neighborhood social cohesion and physical disorder were related to cigarette use (risk ratio=1.09 (0.46, 2.60), 0.86 (0.68, 1.09) and 0.56 (0.47, 0.66), respectively). Moreover, whereas traumatic events and neighborhood physical disorder are associated with an increase in the number of cigarettes smoked per day, neighborhood social cohesion is associated with fewer cigarettes smoked per day. All results are detailed in Table 3.
