Name: JAISA KLAUSS
Publication date: 22/11/2018
Advisor:
Name |
Role |
|---|---|
| ESTER MIYUKI NAKAMURA PALACIOS | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| ESTER MIYUKI NAKAMURA PALACIOS | Advisor * |
| LÍVIA CARLA DE MELO RODRIGUES | Internal Examiner * |
Summary: Substance use disorders are quite prevalent and, potentially, debilitating over the course of the disease. However, therapeutic options with satisfactory efficacy and tolerability are not yet available. Transcranial direct current stimulation (tDCS) is a new modality of non-invasive brain stimulation with few adverse events, which has shown promising results in drug addiction. In this study, we investigated whether the extent of intervention would reduce craving and relapse to alcohol and crack-cocaine use in drug-dependent patients. We conducted randomized, double-blind, sham-controlled trials. Patients with alcohol-use disorder (AUD) and crack-cocaine use disorder (CUD) were allocated to the active tDCS groups [5 x 7 cm2, 2 mA, for 20 minutes, cathode and anode on the left and right dorsolateral prefrontal cortex (dlPFC), respectively] or placebo groups (sham-tDCS). Sham-tDCS or active tDCS was applied every other day, in the total of 10 sessions. Craving was monitored by five items from the obsessive-compulsive drinking or cocaine use scale once a week, for five weeks. Relapses were followed for 90 days after discharge from the hospital. For the alcohol clinical trial, craving scores decreased significantly over the measurements only in the active tDCS group. The effect size was 0.3 and 1.1 for the sham-tDCS and active tDCS groups, respectively. The between groups analysis of craving scores tented to be significant, with an effect size of 0.58, favoring the greater effect in the active tDCS group. After three months post-intervention, 72.2% of the patients in the sham-tDCS group had relapsed, while 72.7% of the active tDCS group remained abstinent. In the study of crack cocaine dependents, craving scores decreased progressively over the measurements in both groups. The effect size was 0.77 and 0.97, in the sham-tDCS and active tDCS groups, respectively. The effect size between groups was 0.34, favoring the active tDCS group. Relapse rates were high and similar between the groups at 30- and 60-days post-discharge. Thus, multiple sessions of tDCS for AUD was well tolerated and showed to be a promising add-on therapy that could be used to reduce alcohol craving and relapse, facilitating alcohol withdrawal. However, extended tDCS sessions for crack cocaine users had no additional effects on craving or relapse to crack-cocaine use in a sample of patients with severe use disorder. Different direct current montages targeting other brain regions and the length of sessions need to be investigated for greater effectiveness in craving control and relapse to crack cocaine use.
