To further test this hypothesis, researchers used data gathered as part of COGA, a multi-center family study that was initiated in 1989. For this analysis, 591 adolescent-parent pairs who participated in COGA between the years of 1991 and 1998 were interviewed: 12- to 17-year-olds were administered the child version of the Semi-Structured Assessment for the Genetics of Alcoholism (C-SSAGA), and one corresponding parent usually the biological mother was also interviewed about each adolescent using the parent version of C-SSAGA.
"The three most commonly used substances as reported by adolescents in our study were alcohol at 54 percent, tobacco at 44 percent, and marijuana at 23 percent," said Bierut. "We then compared the answers given by the teens and parents to see how often they agreed on this use."
The primary finding was that parents often failed to report that their children had used a substance when the children themselves reported that they had. "Specifically, if a child reported having used alcohol, the parent said their child had used alcohol only 50 percent of the time," said Bierut. "Similarly, when a child reported having used tobacco, the parent reported this only 55 percent of the time, and when a child reported having used marijuana, the parent report agreed only 47 percent of the time."
Parents were even more unaware of their child's use of other drugs, added Bierut. "When a child reported using any of the other drugs we asked about for example, cocaine, speed, downers the parent agreed that their child had used any of these drugs in only 28 percent of the cases."
Even among children who reported experiencing symptoms of