The term mood disorder refers to a psychiatric disorder characterized by a prominent mood disturbance, i.e. a manic, depressed, or mixed state. The two prime examples of mood disorder are bipolar disorder and unipolar depressive disorder. Ever since the ground-breaking classificatory work of the German psychiatrist Emil Kraepelin (1856-1926), mood disorders and psychotic disorders have been conceptualized as separate, and more or less independent noso-logical entities. Nevertheless, it is estimated that at sometime in their lives 50-70% of the individuals diagnosed with a mood disorder experience psychotic symptoms. Hallucinations occurring in the context of a mood disorder have been reported in 12-15% of these individuals. In a study among 549 individuals with a clinical diagnosis of a mood disorder, the German psychiatrists Christopher Baethge et al. found a cross-sectional prevalence of hallucinations amounting to 5.89% in individuals with unipolar depression, 10.5% in individuals with bipolar depression, 11.2% in individuals with bipolar mania, and 22.9% in mixed states. The nature of these hallucinations was * auditory (67.7%, the majority of which consisted of * verbal auditory hallucinations), * tactile/* somatic (29.2%), and *visual (26.2%), although hallucinations in the other sensory modalities were also reported. Hallucinations occurring in the context of mood disorders typically present in the form of * mood-congruent hallucinations, although they can also be * mood incongruent in nature.
References
Baethge, C., Baldessarini, R.J., Freudenthal, K., Streeruwitz, A., Bauer, M., Bschor, T. (2005). Hallucinations in bipolar disorder: Characteristics and comparison to unipolar depression and schizophrenia. Bipolar Disorders,7, 136-145.
Goodwin, F.K., Jamison, K.R. (1990). Manic-depressive illness. Oxford: Oxford University Press.
Dictionary of Hallucinations. J.D. Blom. 2010.