The Effects of Cognitive Behavioral Therapy and Transcranial Current Stimulation (tDCS) on Chronic Lower Back Pain

Inclusion Criteria: 1. Ages 18 to 70. 2. United States Veteran or family member of a Veteran. 3. Able to provide informed consent and function at an intellectual level sufficient to allow accurate completion of the assessment instruments. 4. Subjects must be able to comprehend English. 5. Have a chronic pain condition and ≥3months duration of pain. 6. BPI score \>4/10. 7. Meet DSM-5 criteria for current (i.e., past 6 months) prescription opioid use disorder (assessed via the MINI 7.0). 8. COMM score\>7. 9. Subjects may also meet criteria for a mood disorder if asymptomatic or anxiety disorders (PTSD, panic disorder, agoraphobia, social phobia, generalized anxiety disorder, or obsessive compulsive disorder). The inclusion of subjects with affective and anxiety disorders is essential because of the marked frequency of the co-existence of mood and other anxiety disorders among patients with chronic pain and prescription opioid use disorders. 10. Subjects taking psychotropic medications will be required to be maintained on a stable dose for at least four weeks before study initiation. This is because initiation or change of psychotropic medications during the course of the trial may interfere with interpretation of results. 11. Must consent to random assignment to CBT + tDCS or CBT + sham tDCS. 12. Must consent to complete all treatment and follow-up visits. 13. Must live within 100 miles of the Medical University of South Carolina. Exclusion Criteria: 1. Subjects with symptomatic psychotic/bipolar disorder and/or deemed too high risk by the study physician 2. Subjects with current suicidal or homicidal ideation and intent. 3. Subjects with a current eating disorder (bulimia, anorexia nervosa) or with dissociative identity disorder, as they are likely to require specific time-intensive psychotherapy in addition to the proposed therapy for stabilization. 4. Subjects who would present a serious suicide risk or who are likely to require hospitalization during the course of the study. 5. Subjects enrolled in ongoing behavioral therapy for pain or substance use disorders, who are not willing to discontinue these therapies for the duration of the trial. Attendance at therapeutic activities other than study sessions will be closely monitored using the Treatment Services Review. 6. Subjects on maintenance anxiolytic, antidepressant, or mood stabilizing medications, which have been initiated during the past 4 weeks. If it is determined, based on clinical criteria, that…