A Study to Evaluate ABT-126 for the Treatment of Cognitive Deficits in Schizophrenia

• Functioning: UPSA-2 (University of California San Diego Performance-based Skills Assessment-2) [ Time Frame: Measurements from screening period up through week 24 ] [ Designated as safety issue: No ]
  Rater based interview
• Symptom Severity: PANSS (Positive and Negative Symptom Scale) [ Time Frame: Measurements from screening period up through week 24 ] [ Designated as safety issue: No ]
  Rater based interview
• Symptom Severity: NSA-16 (16-item version of the Negative Symptom Assessment Scale) [ Time Frame: Measurements from screening period up through week 24 ] [ Designated as safety issue: No ]
  Rater based interview

This is a efficacy study evaluating a experimental treatment for cognitive deficits in adults with schizophrenia.

Safety and Efficacy Study for Cognitive Deficits in Adult Subjects with Schizophrenia.

• Drug: ABT-126
  ABT-126 Middle Dose
• Drug: ABT-126
  ABT-126 Low Dose
• Drug: ABT-126
  ABT-126 High Dose
• Drug: Placebo
  Placebo

• Experimental: ABT-126 Low Dose
  ABT-126 Low Dose
  Intervention: Drug: ABT-126
• Experimental: ABT-126 Middle Dose
  ABT-126 Middle Dose
  Intervention: Drug: ABT-126
• Experimental: ABT-126 High Dose
  ABT-126 High Dose
  Intervention: Drug: ABT-126
• Placebo Comparator: Placebo
  Placebo
  Intervention: Drug: Placebo

Inclusion Criteria

• Has a current Diagnostic and Statistical Manual of Mental Disorders-, 4th Edition,, Text Revision (DSM-IV-TR) diagnosis of schizophrenia confirmed by the Mini-International Neuropsychiatric Interview (M.I.N.I.).
• Is clinically stable while receiving a regimen of one or two allowable antipsychotic medications: lack of hospitalizations in 4 months prior to initial screening visit; taking the same antipsychotic medication(s) for at least 8 weeks prior to baseline visit; core positive symptoms of Positive and Negative Syndrome Scale (PANSS) no worse than moderate in severity throughout screening period of at least 4 weeks.
• Has been diagnosed with or treated for schizophrenia for at least 2 years prior to initial screening visit.
• Has had continuity in psychiatric care (e.g., mental health system, clinic or physician) for at least 6 months prior to initial screening visit.
• Has an identified contact person (e.g., family member, social worker, case worker, or nurse) that can provide support to the subject to ensure compliance with protocol requirements.

Exclusion Criteria

• In the Investigator's judgment, has a current or past diagnosis of schizoaffective disorder, bipolar disorder, manic episode, dementia, post traumatic stress disorder, or obsessive-compulsive disorder, or the subject has a current major depressive episode.
• Has a positive urine drug screen for cocaine, phencyclidine (PCP), opiates (unless duly prescribed), benzodiazepines (unless duly prescribed), marijuana, or amphetamines during the Screening Period.
• Has a current or past history of seizures, with the exception of a single febrile seizure occurring prior to 6 years of age.
• Has a clinically significant abnormal electrocardiogram (ECG) at Screening Visit 1 as determined by the Investigator.
• Has any risk factors for Torsades de Pointes (TdP)