Attention Deficit Hyperactivity Disorder (ADHD) is a psychological disorder characterized by poor attention span, impulsivity, and hyperactivity. ADHD is primarily treated with prescription stimulants such as Ritalin. However, some evidence suggests dietary supplements, such as omega-3 oil, may benefit those with ADHD. It is important to note that the FDA has not approved any dietary supplement, including omega-3, to treat any disease.
ADHD Symptoms
ADHD is found in approximately 5-15% of children in the United States. Those with ADHD suffer from innattention, hyperactivity and impulsivity. They have a hard time finishing tasks and following instructions, interrupt others, can't wait for turns, forget and lose things. They may also move and talk excessively, and often cannot sit in their seats or play quietly.
Omega-3
Omega-3 is a fatty acid, in the same class as omega-6 fatty acids. Omega-3s are important for cell membranes in brain cells, called neurons, as well as neuronal signaling, and neuron development. Omega-3s include arachidonic acid (AA), docosahexaenoic acid (DHA), dihomo-gamma-linolenic acid (DGLA), and eicosapentaenoic adid (EPA). Humans cannot synthesize the precursor to omega-3s, so the precursor must come from the diet.
Omega-3 Deficiency in ADHD Population
One theory for the cause of ADHD is a deficiency of omega-3s in the diet. Countries with low intake of fish, and thus low amounts of omega-3 in the diet, also have high rates of ADHD. These countries include the United States, Canada, Mexico, Australia, and many European countries. Eating fish later in life does not seem to make up for a childhood deficiency of omega-3s, suggesting that omega-3s are important for brain development, and improper brain development can lead to symptoms of ADHD throughout life. Omega-3s missing in pregnant mothers' diets may be even worse that childhood deficiency, as the brain goes through rapid development in the womb. Unfortunately, many mothers avoid fish due to warnings of detrimental effects of fish high in mercury on the fetus. In 2002, formula for babies began to be fortified with DHA in the United States to remedy this problem.
How Omega-3 Deficiency Could Lead to ADHD
In a rodent study published by Delion in 1995, omega-3 deficiency was associated with reduced dopamine signaling in the cortex, a deficit seen in humans with ADHD. Interestingly, two studies have found children with ADHD have lower circulating levels of fatty acids.
Patients with ADHD are often comorbid for mood disorders, such as depression or bipolar disorder. Omega-3 deficiency has also been theorized to be involved in mood disorders, compounding the ADHD symptoms of those who are comorbid and deficient in omega-3.
Clinical Trials with Omega-3 and ADHD Patients
If ADHD may be caused by omega-3 deficiency, one potential treatment may be to correct the deficiency through dietary supplementation. Results of supplementation are mixed, but there seem to be no ill effects from taking omega-3 supplements. Reports suggest at worst no improvement, and at best improvement of all classes of ADHD symptoms.
Misconceptions
There are several reasons why omega-3 supplementation may not work as a treatment for ADHD for all patients. First, even if ingested, the body still needs to convert the precursors to omega-3s. This conversion may be faulty in some patients, as secretion of stress hormones, excess saturated fat in the diet, a zinc defiency, or excess alcohol intake can disrupt synthesis of omega-3s. Second, if omega-3s are necessary for brain development, supplementation after childhood will not be able to change brain circuitry.
References
- The Merck Manuals: Attention-Deficit/Hyperactivity Disorder (ADHD, ADD)
- "What Causes ADHD?: Understanding What Goes Wrong and Why," Joel T. Nigg; 2006
- "Integrative Pediatrics," Timothy Culbert and Karen Olness; 2010
