Could be. Sometimes individuals present with different symptoms or patterns to the disorder that may result in professionals referring to the presentation as "atypical" for example while all individuals with Bipolar Disorder have a cycle, "rapid cycling" is an atypical presentation of the disorder.
Bipolar. Bipolar I and bipolar II, In the first, manic phases are more severe, and in the second, depressive phases are more severe. There is also cyclothymia which is a low grade version of bipolar disorder in general, where mood swings are not as severe in either direction, manic or depressive. A psychiatrist will look for extreme swings of mood as part of formulating a diagnosis as opposed to testing.
Milder ; Reversed. I've read an article that seems to consider this as perhaps milder in the severity of the ups and downs (cyclothymic) than many full bipolar patients and the "atypical" refers to reversed vegetative symptoms - i.e., oversleeping and overeating as opposed to the more common insomnia and appetite loss. I do not know how or if it is treated with different drugs. Be well. Read more...