Since its release in 1971, the POMS assessment has proven itself to be an excellent measure of affective mood state fluctuation in a wide variety of populations including psychiatric outpatients, medical patients, and in sports psychology. It is suitable for individuals aged 18 and older, and can be completed individually or in groups. The POMS Standard uses a 65-item, 5-point adjective rating scale, while the POMS Brief is based on 30 questions. Both versions of POMS measure six identifiable mood or affective states: Tension-Anxiety, Depression-Dejection, Anger-Hostility, Vigor-Activity, Fatigue-Inertia, and Confusion-Bewilderment.

The BPRS is a clinician-rated tool designed to assess change in severity of psychopathology. It has been in widespread use for more than 30 years and remains popular for research studies that assess patient change in response to treatment interventions. It is an 18-item scale measuring positive symptoms, general psychopathology and affective symptoms. Each symptom construct is rated on a 7-point scale of severity ranging from 'not present' to 'extremely severe.' It takes approximately 20-30 minutes to administer the BPRS.

The SCID-I is a semi-structured interview used to assess the major DSM-IV Axis I diagnoses. The SCID-II is a semi-structured interview for making Axis II (Personality Disorder) diagnoses. Each instrument comes in two versions -- the clinician version, a streamlined version published in two parts, and the research version, which is much easier to modify for a particular study and is more complete. The instrument is designed to be administered by a clinician or trained mental health professional and takes between 1 to 2 hours to complete. Because of its modular format, the SCID can be shortened by focusing only on the diagnoses of interest.