What causes Bipolar Disorder and Attention-Deficit Hyperactivity Disorder (ADHD)?
As with many mental health disorders, scientists are still somewhat uncertain of the causes of both bipolar disorder and ADHD in adults. This stems from, among other things, the complex array of factors that appear to be implicated, the wide range and variability of symptoms and the difficulty of measuring brain chemistry in living subjects. Both disorders are, however, strongly linked to genetics. Bipolar has a heritability level around 0.7 while for ADHD it’s somewhere around 0.75 to 0.9. There is no single gene that triggers either of the disorders, though; instead it is a collection of genes. There are also likely to be physical and social factors involved in the development of both disorders, such as neurotransmitter imbalance, home environment and stress triggers .
