Problems of subject inclusion in psychiatric research: observations from research with psychiatric inpatients.

In a recent study of psychiatric disturbance and decision making behaviour, it was observed that a significant number of psychiatric inpatients experienced difficulties in addressing themselves to the experimental tasks at hand. Despite the large number of studies that have used psychiatric inpatients as subjects, little, if any mention has been made of these difficulties. The following report describes the difficulties that have been observed in the above research project, and examines their possible implications for clinical assessment, research, and for clinical investigations and evaluation of treatment regimes (e.g. effectiveness of particular drug therapies), which use psychiatric inpatient populations as subject sources.