ABSTRACT
The signs and symptoms of schizophrenia are discussed in relation to two symptom groups: positive symptoms type I and negative symptoms type II. The neurodevelopmental aspects are examined, and some of the large number of genes linked to the disorder are described. The biochemistry (dopamine hypothesis) is revisited in relation to the two brain pathways (the mesocortical and mesolimbic pathways). The environmental aspects of schizophrenia are also discussed. The “big brain” theory and preschizophrenia are highlighted as interesting theories. The biology of thought disorder, hallucinations and delusions are explained as far as current knowledge allows. Schizoaffective disorder and schizoid-related personality disorder are discussed.
