Relapse Prevention in Alcohol Dependency by Transcranial Direct Current Stimulation Supported Cue Exposure Therapy

Relapse Prevention in Alcohol Dependency by Transcranial Direct Current Stimulation Supported Cue Exposure Therapy

Alcohol Cue-Reactivity in Patients With Alcohol Dependency and Effects of Transcranial Direct Current Stimulation (tDCS) on Cue-exposure Therapy

Relapse is a major risk in substance abuse disorders, which is closely related to craving for a substance, describing a strong urge for consumption. Cue-exposure therapy is an intervention aiming at the reduction of perceived craving by repeated confrontation. It is based on the assumption that craving drops after repeated exposure without the reinforcing experience elicited by consumption. In the present study, patients with alcohol dependency take part in nine cue-exposure training sessions. Each session consists of mood induction reflecting a high risk situation with subsequent in vivo confrontation with one's preferred alcoholic beverage followed by the training of coping strategies. During the cue-exposure, patients focus on perceiving automatic responses to alcohol-related cues. We hypothesize that especially patients exhibiting initially high reactions to such cues should profit from this intervention the most. The reactions are measured on a subjective (craving) and physiological level (hemodynamics of the prefrontal cortex, heart rate variability, electrodermal activity). Furthermore, we want to strengthen the expected training effects during the cue-exposure by an activating transcranial direct current stimulation of the dorsolateral prefrontal cortex, which has been shown to be hypoactive in substance abuse disorders. We investigate how the cue-exposure training affects the processing of alcoholic cues (cue-reactivity) and its relation to clinical symptoms of alcohol dependency.

During alcohol cue exposure, an active tDCS with a duration of 15 minutes and 2 mA is applied to the left dorsolateral prefrontal cortex (F3, anode) and a reference electrode placed over Fp2 (electrode positions determined by the international 10-20 system). The electrodes are rectangular (35cm2).

During alcohol cue exposure, a placebo tDCS is used with electrodes placed over the left dorsolateral prefrontal cortex (F3, anode) and a reference electrode placed over Fp2 (electrode positions determined by the international 10-20 system). The electrodes are rectangular (35cm2). There is a 20 second ramp going up until 2 mA and back to 0 again at the beginning and the end of the placebo stimulation with no active stimulation during the cue exposure.

The Cue-Reactivity of patients assigned to this arm will be measured twice with an interval of 5 weeks. Afterwards, patients will take part in the cue exposure therapy like subjects assigned to the active arms of the study

2 mA (verum group) over the left dorsolateral prefrontal cortex (F3, anodal), 15 min; 10 seconds ramp in verum and sham group (see also above)

With near-infrared spectroscopy, changes in the concentrations of oxygenated (O2HB) and deoxygenated (HHb) haemoglobin are assessed (in mmol*mm), peaks in those concentrations are evaluated

low frequency/ high frequency (LF/HF) power ratio and standard deviation of the duration between R-peaks (RR) during cue-exposure

Inclusion Criteria: Clinical diagnosis of an alcohol dependence (F10.2) abstinence motivation Exclusion Criteria: epileptic seizures acute psychotic episode another substance use disorder besides nicotine dependency (F17.2) acute withdrawal symptoms