According to the latest research parents do not provide valuable information about their children’s use of alcohol and drugs because they are often unaware of it; and this is true of even the most observant parents, with the most open family relationships who are often oblivious to their children’s use and abuse of alcohol, cigarettes and drugs.

Research from Washington University School of Medicine suggests that parents often fail to report that their children had used a substance when the children themselves reported that they had.

The study is the first attempt to quantify awareness levels, and found that most parents grossly underestimated the scale of the problem among teenagers; even the parents with the most insight were found to have only half the picture.

It seems that even among those children who demonstrated the clearest symptoms of drug taking or dependence, including addiction to Class A drugs, some parents did not suspect their children.

For the study the researchers used data from COGA, a multi-center family study that was initiated in 1989 and conducted 591 interviews with children aged 12 to 17 and a parent, usually their biological mother.

Laura Jean Bierut, associate professor of psychiatry at Washington University School of Medicine and the study author says the three most commonly used substances as reported by adolescents in the study were alcohol at 54 percent, tobacco at 44 percent, and marijuana at 23 percent.

The main finding of the study was that parents often failed to report that their children had used a substance such as alcohol when the children themselves reported that they had and were even less aware of their child’s use of other drugs.

Bierut says when a child reported using any of the other drugs asked about such as cocaine, speed, downers, in only 28 percent of the cases did the parent agree that their child had done so.

Co-author Sherri Fisher,says even among children who reported experiencing symptoms of alcohol or marijuana abuse or dependence, there were parents who did not know that their child had ever used these substances.

Both Bierut and Fisher say that parent reports added very little information to knowledge about adolescent substance use beyond what adolescents themselves were reporting, particularly when compared to other types of psychiatric disorders such as ADHD and ODD.

They conclude that parents do not provide valuable information about their children’s use of alcohol and drugs because they simply don’t know about it and question the use of time and resources in questioning parents about issues of adolescent substance use, abuse or dependence.

Bierut, says the clear message is that teens are using alcohol and drugs and parents are largely unaware of this.

The report is due to be published today in the journal Alcoholism: Clinical & Experimental Research.