03 Apr ADHD and Hormones: Is There a Link?
Attention Deficit and Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder most commonly observed in childhood and adolescence, though symptoms continue into adulthood in approximately 75% cases. In adulthood, symptoms may be associated with concurrent depression or mood disorders, and substance abuse. Many adults with ADHD struggle with work performance and in their personal lives. The disorder disproportionately affects males over females.
Symptoms are heterogeneous, and include:
- Careless mistakes, lack of attention to detail
- Struggling to follow through with instruction
- Lack of organization
- Avoidance of tasks requiring mental effort
- Loses things/forgetful in daily life
- Excessive talking
- Interrupting others
As the patient with ADHD ages, symptom presentation may change. Symptom severity often decreases over time, but some symptoms often persist into adulthood.
Many studies have been conducted to examine the cause of ADHD, and the jury is still out. More than 20 studies have shown that there is a strong genetic link to ADHD, with researchers noting that the disorder is inherited from one generation to another. Along with the genetic involvement, other factors have been postulated to cause ADHD:
- Exposure to lead
- Exposure to bisphenol A (BPA) in plastics
- Exposure to pesticides
- Premature birth/low birth weight
- Maternal stress
- Maternal tobacco use during pregnancy
Scientists at this point believe that there is not one single “cause” for ADHD, and instead it is multifactorial. There are some interesting recent findings about the role that hormones can play in the pathogenesis of ADHD. Endocrine disrupters are chemicals that interfere with production, secretion, and activity of our body’s hormonal system by binding to sites where endogenous hormones are designed to fit. A meta-analysis was conducted in 2018 about the effects that bisphenol A (BPA), a known endocrine disruptor, has on the prevalence of ADHD in children. The authors found that prenatal exposure to BPA was associated with hyperactivity traits in both boys and girls. BPA is extremely prevalent in our society today, present not only in plastics, but also in thermal receipts, recycled paper, and aluminum lined cans. The Centers for Disease Control (CDC) published a study that found BPA in nearly all 2,517 human urine samples it tested, indicating widespread exposure in the USA.
Another novel study published in 2018 looked at the menstrual cycle and how the hormonal fluctuations within contributed to ADHD symptoms in women aged 18-22. By measuring salivary hormone levels in the morning and comparing the participant’s responses to an impulsivity questionnaire, the authors concluded that low estrogen levels relative to progesterone or testosterone (low E2:P ratio or a low E2:T ratio) predicted an increase in ADHD symptom severity the next day. In our practice, we would not recommend replacing estrogen levels in young women, but this study is important to the field of hormone replacement therapy because it highlights the link between hormonal balance and mental well-being.