Pharmacokinetic Study of ABT-126 in Stable Subjects With Schizophrenia

Inclusion Criteria: * Subject has signed informed consent; * Current diagnosis of schizophrenia; * Clinically stable on the same single second-generation (atypical) antipsychotic for the past 8 weeks; * Meets study-specific criteria for Positive and Negative Syndrome Scale (PANSS); * Females are not pregnant, not breast-feeding; * Females are post-menopausal or surgically sterile or practicing birth control; * Males are surgically sterile or agree to be sexually inactive or use barrier method of birth control Exclusion Criteria: * Diagnosis of schizoaffective disorder; * Diagnosis with mental retardation; * Subject has a substance dependence disorder that has not been in sustained remission for at least 1 year; * Acute psychosis hospitalization within past 6 months; * Bipolar disorder, manic episode, dementia, obsessive-compulsive disorder, or drug-induced psychosis or current major depressive disorder; * Current clozapine treatment; * Suicidal ideation or behavior; * BMI of 39 or greater; * Relevant drug sensitivity or allergy; * Positive hepatitis or HIV test result; positive urine screen for drugs of abuse or alcohol; * Recent clinically significant illness/infection or surgery; * Recent blood product transfusion, donation or loss of 5 mL/kg of blood;