Bipolar spectrum: Relevant psychological and biological factors

Figure 1 A continuous relationship of mood disorders with an inflection point. I would like to propose my hypothesis that there is an inflexion point which constitutes the boundary between the bipolar spectrum and unipolar depression. Several findings suggest that temperaments could draw a boundary between bipolar spectrum and unipolar depression. Moreover, it has been shown that certain temperaments may be associated with several biological factors and may be associated with drug response. As such, whilst the concept of the bipolar spectrum emphasizes continuity, it is the proposed inflexion point that discriminates drug responses between the bipolar spectrum (i.e., mood stabilizers) and unipolar depression (i.e., antidepressants).