[Treatable neurometabolic diseases. Association with schizophrenia spectrum disorders]

Schizophrenia spectrum disorders are presented on 1% of subjects over general population. Organic pathologies prevalence in schizophrenia spectrum patients is not well determined, and it is probably underestimated. In the present update review, we are going to highlight seven treatable neurometabolic diseases (NMD) associated to sub-clinic neurological symptoms. It is not infrequent to witness the absence of any clinical neurological signs going along with the NMD. Psychiatric symptoms may be the only clinical alarm that can guide physicians to an acute diagnosis. This is why it is a challenging pathology, defying our clinical accuracy as psychiatrist or any other practitioners confronted to this population. Hereby we are going to expose a literature review and comprehensive tables in order to present in a glance the essential clinical features of disorders of homocysteine metabolism, urea cycle disorders, Niemann-Pick disease type C, acute porphyria, cerebrotendinous-xanthomatosis. These conditions are sensible to major improvement strongly correlated to the accuracy of diagnosis. Literature analysis led us to propose a comprehensive list of atypical psychiatric symptoms including highly predominant visual hallucinations, compared to auditory ones, as well as confusion, catatonia or progressive cognitive decline. We highlight the importance of considering antipsychotic treatment resistance as a crucial sign leading to suspect an organic factor beneath the psychiatric features.