PAB Statement on Environmental Factors and AD/HD

In response to numerous stories about the relationship between AD/HD and certain environmental factors, the CHADD Professional Advisory Board (PAB) approved the following statement on December 4, 2006.

Periodically the news media report a study linking environmental factors to either AD/HD or to the symptoms of inattention or hyperactivity. Some recent examples include maternal smoking during pregnancy, exposure to television during early childhood development, and exposure to toxins such as lead.

These studies do not indicate that AD/HD is "caused" by one or more environmental factors. Rather, they suggest that certain environmental factors are "associated with" AD/HD. Until a causal link is established, "associated with" is the better way to describe the connection between AD/HD and these factors.

Important points to remember:

There is a significant genetic component associated with AD/HD in many families. Some of the genetic component could be vulnerability to certain environmental stressors, because genes usually are expressed by interaction with the environment.
The interplay between genes and the environment has not been well defined.
There is no clear single cause of all cases of AD/HD.

CHADD . . .

calls on the National Institutes of Health, Centers for Disease Control and Prevention, and other institutions of science to finance better studies into these issues; and
calls on the media to be clear whether a study being reported pertains either to the diagnosable neurobiological disorder of AD/HD, to attention in general, or to brain development.