Autoantibody-associated schizophreniform psychoses: clinical symptomatology

According to present concepts, primary psychotic disorders in the schizophrenia spectrum are probably caused by acomplex interaction between multigenetic vulnerability and causally relevant environmental factors. In contrast, secondary psychotic disorders are the result of likely identifiable organic factors either in terms of afirst causation (etiology) or asecondary cause (pathogenesis). In this context, autoantibody(ab)-associated autoimmune encephalitis (AE) plays an increasingly important role. Within the group of ab-associated AE with neuropsychiatric symptoms, anti-N-methyl-D-aspartate receptor encephalitis is the most prevalent one. Psychopathologically, polymorphic psychotic symptoms are often observed at onset of AE; however, over the course of this condition or even initially other neuropsychiatric phenomena are also common. The ill-defined entity of a steroid-responsive encephalopathy with thyroid antibodies (Hashimoto's encephalitis) is aheterogeneous syndrome that may also comprise isolated psychotic disorders presenting as classical schizophrenia.