ADHD And Depression. What Is The Connection?

Childhood ADHD is known to be associated with depression later on in life. Research shows that people with depression- especially bipolar depression are more likely to have ADHD, as well. However, scientists are still trying to understand the exact mechanism.  What is the connection between these two conditions and what are the solutions for both of them? Read on to find out more details. 

Genetics linking ADHD and depression

ADHD tends to run in families and this condition is genetically influenced. There is a genetic overlap between ADHD and depression, as certain gene variations that play a role in the development of ADHD also increase the risk of depression. ADHD tends to run in families because this condition is genetically influenced, and also because they share the same environment.   Some of the most researched genetic variations are related to certain dopamine receptor genes, as well as genes that encode  MAO, and COMT, which also have a significant impact on the brain chemicals dopamine and norepinephrine. Impaired levels of multiple neurotransmitters, including dopamine and norepinephrine, are associated with both ADHD and depression.

A Swedish study evaluated over 13000 twins with ADHD and the association with hypomania, which is part of bipolar disorder ). They found that 13-29% of the genetic risk factors for hypomania were also linked with ADHD, with higher numbers correlating with hyperactive-impulsive ADHD compared with inattentive ADHD. Overall, it is currently believed that  ADHD is mostly influenced by a large number of genes as well as environmental factors.

Environmental risk factors for both ADHD and depression 

Certain environmental factors and other modifiable factors had been associated with both ADHD. Although research is ongoing to better understand this association and did not conclusively implicate them as ADHD risk factors, there is some evidence that links various prenatal substance exposures, heavy metal, and chemical exposures, nutritional factors, and lifestyle/psychosocial factors and increased risk for ADHD

Maternal factors and prenatal exposure to substances like tobacco, alcohol, street drugs like marijuana, cocaine, amphetamines, and heroin as well as excess caffeine, certain blood pressure medications, and the antidepressant bupropion may play a role in the development of ADHD in children. Among heavy metals and chemical exposures, lead, manganese, organochlorines, organophosphate, phthalate,  polyfluoroalkyl chemical exposure showed a potential increased risk for ADHD. 

Nutrient deficiencies are emerging as an important risk factor for ADHD, particularly iron, zinc, omega 3, copper,  magnesium,  vitamins D, C, and B6. Maternal obesity and deficiency is folate also seem to be associated with increased risk for ADHD in children. Food additives particularly synthetic colors and sodium benzoate may also play a role. Western-type diets which are high in empty calories and artificial additives, yet lack essential vitamins and minerals, were also linked with ADHD.  

Among potential risk factors for ADHD associated with lifestyle and psychological factors, it is worth mentioning excess exposure to media and video games, maternal stress, living in institutional settings, and psychological trauma experienced early in life. 

What about environmental risk factors for depression? You will notice that many of the potential risk factors for ADHD also seem to increase the risk of depression, as well. Western-type diets are linked with a higher prevalence of depression, while traditional diets (think Mediterranean diet) may lower the risk for depression.  Multiple nutrient deficiencies, including vitamins D, C, B, magnesium, zinc, iron, omega 3 are also seen more often in those with depression than those without depression. Urinary heavy metals, phthalates, and polyaromatic hydrocarbons were associated with depression in one study. Early psychological trauma and maternal exposure to various toxins may also be involved in the development of depression. 

How do these environmental factors increase the risk of ADHD and depression? They seem to promote brain inflammation, which leads to changes in brain chemistry and neurotransmitter levels, as well as changes in brain function.  

Solutions for both ADHD and depression 

While prescription drugs are considered an essential tool to manage ADHD, they are often not able to fully control the symptoms or help a person build skills needed for day-to-day life. Some organizational skills may improve with drugs but still, a person with ADHD will feel overwhelmed by cleaning a room, completing a project, or plan ahead. Adding psychotherapy can further help improve impulsivity, procrastination and overall boost levels of functioning for both children and adults with ADHD. 

Depression is also treated better with a combination of drugs and psychotherapy. 

While more research is needed to evaluate specific environmental factors that play a role in the development of ADHD and depression, one thing is certain: optimizing the diet and lifestyle will help manage both conditions. Limit consumption of the fast-food diet, and choose instead nutrient-rich foods as recommended by the Mediterranean or other traditional diets. Limit exposure to video games and TV. Stress management strategies like mindfulness meditation, yoga, and regular exercise can further help improve ADHD and depression.