Depressive Disorders and Bipolar and Related Disorders

This chapter describes the mood disorders as well as their diagnosis, symptoms, dimensions, and risk factors. It reviews what is known about the causes and treatment of the mood disorders from various theoretical perspectives. Due to the variation in mood disorders, from more mild and chronic to more severe and episodic, many researchers support the notion that both depression and bipolar disorder should be considered as continua or spectra as opposed to the discrete disorders. In addition to the important distinctions between bipolar and depressive disorders, there are certain dimensions that researchers and clinicians have found useful in classifying mood disorders. The chapter discusses three dimensions: psychotic versus non-psychotic, early versus late onset, and endogenous versus reactive. It describes the importance of life events in the onset of mood disorders, because this was the original basis of the endogenous-reactive distinction.