Transcranial direct current stimulation (tDCS) as an add-on to standardised behavioural therapy for tobacco dependence – a placebo-controlled, double-blind study

Einleitung: The changes in attention and cognitive performance that result from direct current stimulation of different brain regions have been known since the 1960 s and investigated in many studies since then. Our group was able to show improved performance in an n-back procedure (memory test to assess working memory) after tDCS. (Keeser et al; 2010) Proof of this effect in healthy controls leads to the assumption that tDCS increases activity in neuronal networks in tobacco-dependent patients and thus increases attention and concentration abilities, which will in turn increase the probability that smoking cessation during behavioural therapy will be successful within a predetermined period (1, 3, 6 and 12 months).

Methode: Stimulation is performed with a DC stimulator MC. The location of stimulation is anode over the left dorsolateral cortex (DLPFC), corresponding with F3 (in 10 – 20 EEG system); cathode over the right temporal cortex with an intensity of 2 mA. The total duration is a constant stimulation for 20 minutes. The stimulation time schedule for each participant is a total of 7 times over 6 weeks. The stimulation is followed by a 90-minute session of the 'Smoke-free programme', a standardised behavioural therapy of the Institute for Therapy Research (Gradl, S. Kröger C., 2008) Different Evaluation scales are used are for example the Fagerström Test and Questionnaire on Smoking Urges. As an additional evaluation, at the start of the stimulation and at four follow-up appointments salivary cotinine and the carbon monoxide content of expired air are measured. Additional we perform two fMRT's (at baseline and at the end of study) to examine the effects of anodal tDCS of the left (DLPFC) in tobacco dependence.

Diskussion/Ergebnisse: Actually all of the planned participants (n = 52) have passed through our study. Results will be presented.

Schlussfolgerung: tDCS is practicable in larger groups (8 – 12 people). Significantly higher quit rates with tDCS as an add-on. Co-activations of intrinsic fMRT connectivity after tDCS and therapy compared to baseline. Increased connectivity was found in the striatum and the right frontal cortex.