Brain Laterality and Psychopathology

Abstract

The aim of this review is to evaluate if data on laterality of brain lesions producing various kinds of secondary psychopathology can help to choose between the two main models advanced to explain emotional lateralization, namely (a) the "Different Hemispheric Specialization for Positive and Negative Emotions" hypothesis and (b) the "General Right Hemisphere Dominance for Emotions" hypothesis. According to the first model, a major depression should usually result from disruption of the left-sided "center for positive emotions," whereas a manic syndrome should result from inactivation of the right-sided "center for negative emotions"; according to the second model, various forms of secondary psychopathology should prevail in patients with right-hemisphere damage. The results of this review are more consistent with the right hemisphere dominance than with the different hemispheric specialization hypothesis, because they show that some kinds of secondary affective disorders (namely mania and manic-depressive disorders), some forms of content-specific delusional syndromes, and some developmental social-emotional disorders are strongly linked to right-hemisphere lesions.