Evaluate the Efficacy of Armodafinil for Patients With B-cell Lymphoma and Severe Fatigue

Inclusion Criteria for both arms: * Age ≥ 18 with diagnosis of B-cell lymphoma * Average score of ≥ 7 on daily worst fatigue severity assessment from the BFI questionnaire during screening * Able to demonstrate appropriate use of the wrist actigraphy device and to complete questionnaires * ECOG performance status 0-2 * Laboratory values: * Hemoglobin ≥ 10 g/dL * Total Bilirubin ≤ 1.5 x institutional ULN * AST/ALT ≤ 2.5 x institutional ULN * Creatinine ≤ 1.5 x institutional ULN * Albumin ≥ 3.5 g/dl * Life expectancy \> 6 months * IRB-approved informed consent form must be signed before any protocol-specific screening procedures are performed. Inclusion criteria for patients undergoing R-CHOP chemotherapy: * Scheduled to receive 6 cycles of standard R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy as first-line treatment Inclusion criteria for patients in remission following chemotherapy and/or radiotherapy: * May have received one prior regimen of chemotherapy and/or radiotherapy * Adequate response to upfront chemotherapy and/or radiotherapy * Indolent lymphomas - must have achieved a partial or complete response with no immediate plans for further treatment * Aggressive lymphomas - must have achieved a complete response: * ≥ 4 weeks since completion of chemotherapy * ≥ 8 weeks since completion of radiotherapy * ≤ 18 months since completion of chemotherapy or radiotherapy Exclusion Criteria for both arms: * Uncontrolled medical and/or psychiatric condition that may cause fatigue or that the PI feels is clinically significant and might adversely affect patient safety (such as sleep disorders, moderate/severe depression, metabolic/endocrine abnormalities, infections) * History of clinically significant cardiac disorders, such as left ventricular hypertrophy or mitral valve prolapse experienced in conjunction with receiving CNS stimulants * History of serious skin reactions, such as serious rash or Stevens-Johnson Syndrome * Concurrent stimulant medication * Any other active malignancy within the past 3 years except cervical carcinoma in situ and non-melanoma skin cancers * Known CNS involvement by lymphoma * Cachexia * Use of opioids at time of randomization * Known sensitivity to modafinil and/or armodafinil