tDCS for Chronic Low Back Pain

Inclusion Criteria: * Chronic Low Back Pain ≥ 6 months duration in the lumbar region, present more than half the days of the month, and on average be at a moderate level of severity in the last month * At least one trial of physician recommended medication (e.g. acetaminophen, NSAIDS, skeletal muscle relaxants) * Pre-existing opioid and non-opioid pain medication must be non-existent or stable (medications have not changed for one month) * Be able to understand, read and write English * If female and of childbearing age, agree to use acceptable birth control during the study treatment period (oral contraceptives, history of tubal ligation, history of a hysterectomy, or a reliable barrier method) Exclusion Criteria: * Lifetime Diagnostic and Statistical Manual (DSM) IV diagnosis of bipolar disorder, schizophrenia, or other chronic psychotic condition * Current DSM-IV diagnosis of substance dependence for alcohol, sedative/hypnotic drugs, stimulants, cocaine * Current cancer, infection, or inflammatory arthritis * Broken skin or other lesions in the area of the electrodes * Uncontrolled medical problems, such as diabetes mellitus, hypertension, pulmonary or airway disease, heart failure, coronary artery disease, or any other condition that poses a risk for the subject during participation * Presence of metal in the cranial cavity * Holes in the skull made by trauma or surgery * Pacemakers, medication pumps, and other implanted electronic hardware * Pregnancy