ABSTRACT
Depression is one of the moods to which we are subject, and mood disorder, which includes also bipolar disorder, considerably exceeds schizophrenia in its frequency and rivals it in its destructive potential; both types of disorder are associated with greatly increased risk of suicide. Like the other neurodevelopmental frontostriatal disorders, it lies on a continuum with normal behaviour, and may be associated with evolutionarily adaptive aspects, in this case in the context of creativity. In this chapter we shall note its recurring characteristics, shared with schizophrenia, its comorbidity with other conditions, its neuropsychological concomitants, and changes, morphometric and functional, that are associated with induced alterations in mood, clinical depression, and bipolar disorder. We shall note the often confusing ®ndings with respect to lateralisation and the absence, so far, of evidence of any particular ``Jeremiah gene'', despite the high degree of heritability associated with the two major types of mood disorder.
