Met-enkephalin level in the cerebrospinal fluid of schizophrenic patients

The level of met-enkephalin in the cerebrospinal fluid of 18 schizophrenic and 18 non-mental patients were determined by radioimmunoassay. The concentration of this peptide in the schizophrenic patients ranged from 12 to 39 ng/l with a mean of 22.2 ng/l. The mean and range of the non-mental patients were 28 ng/l and 16 to 41 ng/l, respectively. The difference between the mean enkephalin level of the two groups was statistically significant by the t-test. However, this difference must be interpreted with caution since the data obtained from the non-mental patients cannot be regarded as normal. No significant correlation was observed between the severity of schizophrenic symptoms and cerebrospinal fluid met-enkephalin level.