The etiology of schizophrenia and the origin of language: overview of a theory.

Journal article

Schizophrenia is present in all human populations with approximately the same incidence. Why does such illness persist given that it is associated with a reproductive disadvantage? What is the balancing advantage? A possible explanation is linked to human language. According to this hypothesis schizophrenia occurs as a manifestation of genetic diversity associated with language--the function by which Homo sapiens has separated from other primate species. Language originated by a genetic mutation that allowed the cerebral hemispheres to develop with a degree of specialization (or lateralization) reflected in cerebral asymmetries. Individuals with schizophrenia show lesser structural and functional brain asymmetries than the population as a whole, and this finding can be interpreted as a delay, or failure in, establishing hemispheric dominance for language. We review recent evidence supporting this theory.

Authors: Berlim, M; Mattevi, B; Belmonte-de-Abreu, P; Crow, T

• Journal: Comprehensive psychiatry
• Volume: 44
• Issue: 1
• Pages: 7-14
• Publication date: 2003-01-01
• DOI: 10.1053/comp.2003.50003
• EISSN: 1532-8384
• ISSN: 0010-440X
• Language: English
• Keywords: Brain; Language; Functional Laterality; Chromosomes, Human, Pair 21; Schizophrenia; Point Mutation; Psychological Theory; Incidence; Humans; Chromosomes, Human, X