[Encephalitis or schizophrenia as a cause of cognitive decline]

In this case report, a young male patient presented with cognitive decline and behavioural changes, initially suspected as early schizophrenia. Impaired consciousness and mononuclear pleocytosis in CSF suggested an organic cause. Extensive testing was inconclusive, and treatment with corticosteroids and immunoglobulins improved symptoms but left cognitive deficits. Antipsychotics were ineffective, and no psychiatric illness was identified. The case highlights diagnostic challenges between neurology and psychiatry, suggesting possible neuroinflammation of unknown origin with a poor prognosis for a full recovery.