Bipolar I,

Dr. Agop Akiskal, a seriously recognized Bipolar researcher, looked into the "Spectrum of Bipolar" diagnoses within the DSM-IV and ICD-10 criteria for mania and depression now expanded to include Schneider's often-experienced types:

Bipolar, Type I : Extremes of Mania and Depression
Bipolar, Type II: Hypomania rather than classic mania
Bipolar, Type III: Depressed and becomes hypomanic due to antidepressant
medication therapy
Bipolar, Type IV: Cycles of depression and "hyperthermia"
Bipolar, Type V: Depressed patient with bipolar relatives
Bipolar, Type VI: Mania without depression

These determinations "bumped" prevalence of bipolar illness to 5% from 1%.

Within these various types, there are degrees of illness.

I think that's what you were probably alluding to in your concept that there are two types of bipolar illness.

Genetic