A theoretical reappraisal of mixed states: dysphoria as a third dimension

Mixed states are heterogeneous clinical entities difficult to define precis ely. The stringent actual DSM IV criteria are unsatisfactory for current cl inical use. Many; frequently encountered mixed patients benefit without an accurate diagnosis from biological therapeutic interventions such as the in troduction of mood stabilizers. We propose a brief review of the definition and characteristics of mixed states and propose a new approach to the typo logy of mixed states. Based on recent literature data, we add to the depres sive and manic syndrome the concept of dysphoria as a third dimension. Inte grating this three dimensional approach with recent factor analysis, we des cribe in addition to the DSM IV mixed state (type I) two new subtypes of mi xed states (type IIM and IIB). This new typology can give the clinician a m ore accurate understanding of the complex and polymorphous reality of mixed states and help him make more specific therapeutic interventions. These su btypes of mixed states will need validation through prospective clinical st udies. Biological differences, differential outcome over time, and differen tial response to treatment will be important validation criteria.