There is a significant incidence of psychiatric symptoms in patients with multiple sclerosis, the most common after receiving the diagnosis. We describe a man who was admitted for a first episode psychosis and a diagnosis of multiple sclerosis was made moreover.

A 24-year-old man was admitted with a paranoid delusion, auditory hallucinations with emotional response and the believe that their thoughts were being interfered. Blood test and cranial CT were normal. Risperidone was started. He developed ataxia and sensitive disturbances on the right arm. A cranial and spinal cord MRI revealed multiple T2 and FLAIR hyperintense lesions located in supra and infratentorial white matter, lesions in C3, and one lesion in right basal ganglia that enhanced with gadolinium. CSF analysis showed oligoclonals bands. Three years ago the patient had had transient sensitive symtoms. A diagnosis of relapsing-remitting multiple sclerosis was made and was started methyl-prednisolone intravenously. Risperidone was changed for amisulpride 800 mg/day because lack of response. He was discharged after 25 days. Six months later he has attenuated psychotic symptoms without news lesions in MRI. Glatiramer acetate has been started.

The most frequent disorder associated to multiple sclerosis is depression (prevalence of 20%). Psychosis is unusual, transient, sometimes as the onset relapse followed by remission. There's evidence of correlation between psychosis in multiple sclerosis and multiple lesions in temporal periventricular area. We suggest that in our case these two disorders are two separated entities since the enhanced lesion does not correpond with clinical findings.