Environmental Factors in ADHD

ADHD is a heritable disorder. Available evidence, however, strongly points to environmental as well as genetic factors as causative for ADHD. 

State Percentage Diagnosed with ADHD Percentage Drug Treated for ADHD 

Beyond the genetic factors, the causes of ADHD are unknown and very few studies have examined the relationship between ADHD and exposures to environmental chemicals. It is known, however, that maternal prenatal exposures to lead, alcohol, tobacco smoke, and marijuana are known to result in the birth of children with high incidences of ADHDJ14-17 ft has also been established that exposure to excessive quantities of phenylalanine either prenatally in utero, as a result of the mother having phenylketonuria (PKU) and fetus not having PKU, or postnatally where the child has PKU, results in the development of ADHD hyperactive and behavioral 

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