Bilateral Prefrontal Modulation in Alcoholism

Five items from the original obsessive compulsive drinking scale, which are believed to reliably assess craving in a narrow sense were used. Questions of this brief scale allow quantification of thoughts and feelings (obsessions), and behavioral intentions, and are answered on a scale ranging from 0 to 4, resulting in a total score between 0 and 20. Higher scores reflect more severe craving. These items were applied at the beginning, during and at the end of the treatment with sham-tDCS or tDCS.

The FAB was used to explore six different domains of executive function. Each of these items is scored from 0 (zero) to a maximum of 3. Thus, the maximum score, meaning better scores, of FAB is 18. A single well trained examiner administered this assessment.

An adapted version of the MMSE in Portuguese was used. This version included an 11-item examination that examined five areas of cognitive function: orientation, registration, attention and calculation, recall, and language. The maximum score, meaning better scores, that could be achieved was 30, while a mean score between 23 and 26 or between 26 and 29 would be expected according to the age and educational level of the alcoholics.

A structured multiple-choice questionnaire was used to assess the severity of depression symptoms. This instrument assesses the severity of symptoms observed in depression, such as low mood, insomnia, agitation, anxiety and weight loss (Hamilton, 1960). Each question has between 3 and 5 possible answers that increase in severity. In the original scale, the first 17 questions contribute to the total score, while questions 18 to 21 provide additional information about depression (e.g., diurnal variation, paranoid symptoms), but are not included in the total score of the scale. Scores of 0-7 are considered as being normal, 8-16 suggest mild depression, 17-23 moderate depression and scores over 24 are indicative of severe depression; the maximum score is 52.

A structured multiple-choice questionnaire designed to assess the severity of anxiety symptoms was employed. The scale consists of 14 items, each defined by a series of symptoms, and measures both psychic anxiety (e.g., mental agitation and psychological distress) and somatic anxiety (e.g., physical complaints related to anxiety). The higher the scores, higher the severity. Each item is scored on a scale of 0 (not present) to 4 (severe), with a total score range of 0-56, where below 17 indicates mild severity, 18-24 mild to moderate severity and 25-30 moderate to severe.

Electrophysiological recording was obtained through a 32-channel system placed on the scalp according to the International 10/20 EEG system.

A cue-reactivity paradigm was adapted following standard cue-reactivity paradigms well established for pictures and videos. During picture presentation the subjects were asked to press a button whenever the drug-related pictures were presented, and to withhold the response when the neutral pictures were presented (50% of the time). The percent change of ventral medial Prefrontal Cortex current density was analyzed.

An abbreviated instrument of cross-culturally valid assessment of quality of life of the World Health Organization (WHOQOL-BREF) with 26 questions translated to Portuguese was applied at the beginning and at the end of the five-week treatment. This instrument yields four domains (physical health, psychological, social relationships and environment) and two individually scored items regarding overall perception of quality of life (Q1, i.e., first question) and health (Q2, i.e., second question). The four domain scores are scaled in a way that higher scores stand for higher quality of life. These scores were transformed to be comparable with the scores used in the WHOQOL-100.