Obstructive hydrocephalus caused by colloid cyst presenting as a schizophrenia-like psychosis.

This report presents a young woman with psychotic symptoms that were highly suspicious of schizophrenia. Previous attempts of antidepressant therapy of mood symptoms had been ineffective. However, she also presented with discrete signs of an underlying neurological condition, and as a part of the diagnostic workup, neuroimaging revealed ventriculomegaly. She was diagnosed with obstructive hydrocephalus and experienced full remission of psychotic symptoms after neurosurgical intervention with a ventriculoperitoneal shunt. This atypical presentation of obstructive hydrocephalus underlines the importance of neuroimaging in psychiatric differential diagnostics. Otherwise, this young woman had been diagnosed with schizophrenia, instead of organic delusional disorder secondary to a neurological condition, with possible irreversible damage to brain tissue as a consequence.