Structured assessment of current mental state in clinical practice: an international study of the reliability and validity of the Current Psychiatric State interview, CPS-50

Objective: To develop a reliable standardized assessment of psychiatric symptoms for use in clinical practice. Method: A 50-item interview, the Current Psychiatric State 50 (CPS-50), was used to assess 237 patients with a range of psychiatric diagnoses. Ratings were made by interviewers after a 2-day training. Comparisons of inter-rater reliability on each item and on eight clinical subscales were made across four international centres and between psychiatrists and non-psychiatrists. A principal components analysis was used to validate these clinical scales. Results: Acceptable inter-rater reliability (intra-class coefficient > 0.80) was found for 46 of the 50 items, and for all eight subscales. There was no difference between centres or between psychiatrists and non-psychiatrists. The principal components analysis factors were similar to the clinical scales. Conclusion: The CPS-50 is a reliable standardized assessment of current mental status that can be used in clinical practice by all mental health professionals after brief training.