We will look at various models of psychopathology. The basic assumption is that psychological disorders are diseases. Of the etiological factors that we have examined, the biological realm is primary. To understand psychopathology, we need not look beyond the biological level. A thought is a neurological event in the brain.
Psychopathology is a biological phenomenon.
Research and treatment will focus on searching for and altering biological variables. Biology simply can't account for psychological disorders. At the very least, to truly understand a psychological disorder, we need to integrate knowledge from these various levels with the biological level. We need to recognize that each level has its own strengths, but also its own limitations. Both sets of questions are important in understanding a phenomenon.