While the exact cause of attention deficit/hyperactivity disorder (ADHD) is not clear, research efforts continue.
Multiple factors have been implicated in the development of ADHD. It can run in families, and studies indicate that genes may play a role. Certain environmental factors also may increase risk, as can problems with the central nervous system at key moments in development.
Risk factors for ADHD may include:
- Blood relatives (such as a parent or sibling) with ADHD
- Exposure to environmental toxins — such as lead, found mainly in paint and pipes in older buildings
- Drug use, alcohol use or smoking during pregnancy
- Maternal exposure to environmental poisons — such as polychlorinated biphenyls (PCBs) — during pregnancy
- Premature birth
Although sugar is a popular suspect in causing hyperactivity, there's no reliable proof of this.
Apr. 24, 2014
See more Expert Answers
- Attention-deficit/hyperactivity disorder. In: Diagnostic and Statistical Manual of Mental Disorders DSM-5. 5th ed. Arlington, Va.: American Psychiatric Association; 2013. http://www.psychiatryonline.com. Accessed April 4, 2014.
- Attention deficit/hyperactivity disorder. National Institute of Mental Health. http://www.nimh.nih.gov/health/publications/attention-deficit-hyperactivity-disorder/index.shtml. Accessed April 7, 2014.
- Bader A, et al. Complementary and alternative therapies for children and adolescents with ADHD. Current Opinion in Pediatrics. 2012;24:760.
- Goodlad JK, et al. Lead and attention-deficit/hyperactivity disorder (ADHD) symptoms: A meta-analysis. Clinical Psychology Review http://www.sciencedirect.com/science/journal/02727358/33/3 2013;33:417.
- Lindstrom K, et al. Preterm birth and attention-deficit/hyperactivity disorder in school children. Pediatrics. 2011;127:858.