Diagnostic errors using the Short Portable Mental Status Questionnaire with a mixed clinical population.

The validity of the Short Portable Mental Status Questionnaire (SPMSQ) was evaluated using two criteria: clinical diagnosis and neuropsychological diagnosis. The 40 study participants represented a mixed clinical sample of neurologic and psychiatric patients, all of whom were or had been inpatients. Laboratory data (CT, EEG, etc.) were available for 45% of the patients. Neuropsychological diagnosis of organic impairment was based on an extensive test battery. The SPMSQ did not significantly relate to either clinical or neuropsychological diagnosis. It is recommended that a "normal" score on the SPMSQ be regarded as nonspecific regarding organic cognitive impairment rather than suggestive of normal brain functioning.