Study endpoint in preceding base study M10-855 not met.

This is a study of ABT-126 in the treatment of cognitive impairment associated with schizophrenia (CIAS), a long-term extension study to study M10-855 (NCT01655680).

Inclusion Criteria:

• The subject was randomized into Study M10-855 and completed through Week 26 in that study.
• The subject is receiving one or more antipsychotic medications.

Exclusion Criteria:

• Additional history collected during participation in Study M10-855 provides evidence that, in the investigator's judgement, the subject does not have schizophrenia.
• The subject experienced an adverse event or abnormal finding during physical examination, vital signs, laboratory profile, and/or electrocardiogram (ECG) measurements in Study M10-855 that indicates the subject is likely to become medically unstable during the current study.
• The subject is currently taking or is expected to be prescribed any excluded medication without the approval of AbbVie medical monitor.
• The subject is currently enrolled in, or plans to participate in, another interventional study during the course of this trial.