Study Evaluating Vabicaserin in Subjects With Schizophrenia

PANSS assesses the positive symptoms, negative symptoms, and general psychopathology specifically associated with schizophrenia. The scale consists of 30 items. Each item is rated on a scale from 1 (symptom not present) to 7 (symptoms extremely severe). The sum of the 30 items is defined as the PANSS total score and ranges from 30 to 210; higher score indicates greater severity.

PANSS assesses the positive symptoms, negative symptoms, and general psychopathology specifically associated with schizophrenia. The scale consists of 30 items. Each item is rated on a scale from 1 (symptom not present) to 7 (symptoms extremely severe). The sum of the 30 items is defined as the PANSS total score and ranges from 30 to 210; higher score indicates greater severity.

PANSS positive subscale assesses positive symptoms associated with schizophrenia. The positive subscale consists of 7 items (delusions, conceptual disorganization, hallucinatory behavior, excitement, grandiosity, suspiciousness/persecution, and hostility). Each item is rated on a scale from 1 (symptom not present) to 7 (symptoms extremely severe). Total positive subscale scores range from 7 to 49; higher score indicates greater severity.

PANSS negative subscale assesses negative symptoms associated with schizophrenia. The negative subscale consists of 7 items (blunted affect, emotional withdrawal, poor rapport, passive/apathetic social withdrawal, difficulty in abstract thinking, lack of spontaneity and flow of conversation, and stereotyped thinking). Each item is rated on a scale from 1 (symptom not present) to 7 (symptoms extremely severe). Total negative subscale scores range from 7 to 49; higher score indicates greater severity.

General psychopathology subscale assesses general psychopathology symptoms associated with schizophrenia. The general psychopathology subscale consists of 16 items (somatic concern, anxiety, guilt feelings, tension, mannerisms/posturing, depression, motor retardation, uncooperativeness, unusual thought content, disoriented, poor attention, lack of judgment/insight, disturbance of volition, poor impulse control, preoccupation, and active social avoidance). Each item is rated on a scale from 1 (symptom not present) to 7 (symptoms extremely severe). Total general psychopathology subscale scores range from 16 to 112; higher score indicates greater severity.

Cognition cluster subscale assesses cognitive symptoms associated with schizophrenia. The cognition cluster subscale score is a sum of 5 items from positive, negative and general psychopathology subscales (conceptual disorganization, difficulty in abstract thinking, poor attention, lack of judgment and insight, and preoccupation). Each item is rated on a scale from 1 (symptom not present) to 7 (symptoms extremely severe). Total cognition cluster subscale scores range from 5 to 35; higher score indicates greater severity.

Responders were defined as 20 percent (%) responders and 50 % responders. A 20% responder was a participant whose PANSS total score was decreased by at least 20% from baseline to the week of assessment. A 50% responder was a participant whose PANSS total score was decreased by at least 50 % from baseline to the week of assessment. PANSS total score assesses the positive symptoms, negative symptoms, and general psychopathology specifically associated with schizophrenia. The scale consists of 30 items. Each item is rated on a scale from 1 (symptom not present) to 7 (symptoms extremely severe). The sum of the 30 items is defined as the PANSS total score and ranges from 30 to 210; higher score indicates greater severity.

CGI-S: 7-point clinician rated scale to assess severity of participant's current illness state; range: 1 (normal - not ill at all) to 7 (among the most extremely ill patients).

CGI-I: 7-point clinician rated scale to assess global improvement in the participant's clinical state compared to baseline; range: 1 (very much improved) to 7 (very much worse).

CDSS: 9-item clinician rated scale, validated for rating the severity of depressive symptoms in participants with schizophrenia. Each item is rated on a 4-point scale ranging from 0 (absent) to 3 (severe). CDSS total score is the sum of each item scores and ranges from 0 to 27; higher score indicates more severity of symptoms.