Testing the Ability of JNJ-18038683 to Improve Cognition and Reduce Depressive Symptoms in Stable Bipolar Patients

Inclusion Criteria 1. All participants must have signed an informed consent document indicating they understand the purpose of the study and the procedures required for the study and are willing to participate by complying with the study procedures and restrictions. 2. Male or female individuals of any race; between 18 to 60 years of age, inclusive. 3. Resides in a stable living situation, according to the investigator's judgment. 4. Diagnosis of bipolar disorder I or II for at least 1 year in duration, as established by the SCID-I, and verified with medical records and/or confirmation of diagnosis by treating clinician. Patients will be in a nonacute phase at the time of initial screening and have been so for at least 1 month. 5. No more than moderate clinical symptom burden severity, as defined by the following: Montgomery Asberg Depression Rating Scale \< 20 Young Mania Rating Scale \<12 6. Individuals medically stable enough to complete an 8 week clinical trial, in the judgment of the investigator 7. Women of childbearing potential must have a negative pregnancy serum test at screening, negative pregnancy urine test at baseline, and agree to use adequate protection (i.e. double barrier method) for birth control. 8. Antidepressant (AD) medications are allowed if the subject has been treated with a stable dose for at least 2 months before screening. 9. Individuals receiving a single mood stabilizer (e.g., lithium. valproate, or lamictal) are allowed if a stable dose has been maintained for at least 2 months prior to screening. 10. Individuals may be receiving one treatment of each the following groups: antidepressants, mood stabilizers, and atypical antipsychotics other than clozapine, but not more than one from each group. 11. Individuals taking ripseridone, lurasidone, or ziprasidone must be currently taking \< doses of 3mg, 40mg, and, 80mg, respectively. 12. Subjects may be treated with inclusionary antipsychotic drugs as long as they are on a stable dose of injectable medication for 2 months or a sable dose of an oral medication for 1 month. Exclusionary antipsychotic drugs are listed in Appendix 2 in the protocol. 13. Patients with a history of compliance with a drug treatment regimen for bipolar disorder, as noted in medical/psychiatric history. 14. CNS stimulants (e.g., Adderall, Ritalin) are permitted if the participant is stable on their dosage of medication for 1 month before screening and cannot change dosage throughout the study. 15. Able to complete cognition assessments in English 16. Individuals must demonstrate a substantive cognitive deficit, as measured by the Trails A, Hopkins Verbal Learning Test (HVLT), and the Letter Number Span, administered at the screening visit. Eligible individuals will have an established cognitive deficit as measured by one or more of these tests, scoring below the 75th percentile, using comparative norms according to age, gender, and education. 17. Able to understand and complete cognition assessments Exclusion Criteria 1. Failure to perform screening or baseline examinations 2. Hospitalization within 8 weeks before screening, or change in mood stabilizing or antidepressant medication or dose within 2 months prior to screening. 3. Individuals who have participated in another clinical study within the past 2 months. 4. Individuals with tardive dyskinesia. 5. Individuals with other DSM-V Axis I or Axis II primary diagnoses. 6. Diagnosis of alcohol or substance use disorder within the past 3 months. 7. Subject assessed to be at significant suicide risk based on responses to the Columbia Suicide Severity Rating Scale (C-SSRS). 8. History of myocardial infarction, unstable angina, uncontrolled hypotension or hypertension within 3 months before screening. 9. Clinically significant abnormality on screening ECG. 10. Alanine transaminase (ALT) or aspartate transaminase (AST) \> 2.5 times the upper limit of normal (ULN). 11. History of stroke, brain tumor, head trauma with loss of consciousness, or other clinically significant neurological condition within 12 months before screening. 12. Individuals with other uncontrolled medical conditions, in the opinion of the investigator. 13. Use of drugs known to be metabolized by CYP2D6.