Behavior Problems Inventory (BPI): Psychometric characteristics of an instrument for routine assessment of persons with psychoses and related disorders

•The behavior problems inventory- BPI- shows high reliability, as well as satisfactory validity.•The BPI assess three dimension: underactivity/Social Withdrawal, Active Problems and Lack of Impulse Control.•The BPI- is easy to apply, allowing routine assessment for persons diagnosed with psychosis and bipolar affective disorder for whom key family informants are available. This study explores the psychometric characteristics of the Behavior Problems Inventory (BPI), an instrument for routine clinical assessment of behavior problems in outpatients with psychosis based on information provided by key family informants. Six hundred and twenty-one patients diagnosed with psychosis and bipolar affective disorder (ICD-10 F20-F31) attended at Community Mental Health Units were evaluated in routine reviews using the BPI and the Social Functioning Scale (SFS). Twenty-five subjects were simultaneously administered the Social Behavior Schedule (SBS) and 28 were again administered the BPI eight weeks later. The instrument shows adequate psychometric characteristics with high internal consistency and robust temporal reliability, as well as satisfactory concurrent and construct validity. Factor analysis identified three factors: Underactivity/Social Withdrawal, Active Problems and Lack of Impulse Control, with adequate saturation of the items on each of the factors. The BPI is easy to apply, reliable and valid, takes up little of valuable clinical time, allowing routine assessment in public service contexts for persons diagnosed with psychosis and bipolar affective disorder for whom key family informants are available.