Can ADHD mimic Bipolar Disorder?

A. The relationship between attention deficit hyperactivity disorder (ADHD) and bipolar disorder is not quite clear. There have been some studies showing no relationship, others showing that bipolar disorder is unusually common in children or adolescents with ADHD. There are also some individuals who, by the luck of the draw, end up with both disorders -- a state termed "comorbidity." This refers to the chance occurrence of two conditions, without implying any genetic or physiologic similarity. Some clinicians have speculated that ADHD is a kind of "precursor" to later development of bipolar disorder, but this has not been proven. There is some symptomatic overlap between ADHD and individuals with hypomanic symptoms, such as unusual amounts of motor activity and tendency to be overexcited and "rub people the wrong way."
Untreated, both ADHD and bipolar individuals often end up "self-medicating" with alcohol or other substances of abuse, leading to more disturbed behavior and mood swings. In theory, someone with rapidly recurring unipolar major depression and ADHD might seem to mimic bipolar disorder, appearing superficially to fluctuate between depression and hypomania (which is less severe than mania). However, the true bipolar patient with hypomania usually shows a constellation of signs and symptoms of an elevated mood state, such as excessive spending, grandiose ideas, increased sexual or social activity and decreased need for sleep. It would be the rare ADHD individual who would show two or more of these at the same time.
Moreover, ADHD is constant--it doesn't come and go in the way that bipolar disorder does. Family history can be an important clue. If there is a family history of clear bipolar disorder, that helps make the diagnosis. Also, individuals with ADHD will usually improve with Ritalin. The patient with bipolar disorder (in the hypomanic state) will worsen, often going into a full-blown manic state. There is no credible evidence that I know of showing that lithium is effective for ADHD, though it may help patients with both bipolar disorder and ADHD .

Source:www.healthyplace.com