Psychiatric disorders in inpatients on a neurology ward: estimate of prevalence and usefulness of screening questionnaires

Background: Patients on neurology wards have been shown to have high rates of psychiatric illness. Prevalence figures of 39-64% have been reported previously. However a low rate of recognition of psychiatric illness is also observed in this population. Objectives: To estimate the prevalence of psychiatric illness in neurology inpatients in a regional neuroscience centre and to assess the sensitivity and specificity of a batch of screening questionnaires. Method: Patients were assessed using the following screening questionnaires: Primary Care Evaluation of Mental Disorders, Mini Mental State Examination, Frontal Assessment Battery, Alcohol Use Disorders Identification Test and a neurologist-rating scale of organicity. All patients also had a full psychiatric assessment using the Diagnostic and statistical manual of mental disorders, 4th edition (DSM-IV). The screening questionnaires were then compared with our gold standard'', the psychiatric assessment. Results: The prevalence of psychiatric illness (as determined by the psychiatric interview) in neurology inpatients in a tertiary referral centre was found to be 51.3% (95% confidence interval 44 to 58%). The sensitivity of this batch of screening questionnaires is 81.2% and the specificity is 77.1%. Conclusion: A high prevalence of psychiatric disorder was observed in inpatients on a dedicated neurology ward. The screening questionnaires used had a high sensitivity and specificity and could therefore be used as a simple way of identifying those with psychiatric illness.