Table 1.

MEP amplitudes and stimulation intensity before and after varenicline administration.

Stimulation	TMS Parameter	Medication condition	Baseline 1	Baseline 2	Baseline 3
Cathodal tDCS	MEP	0.3 mg	0.97 ± 0.13	1.01 ± 0.19	0.93 ± 0.13
		1.0 mg	0.94 ± 0.11	0.81 ± 0.13	0.92 ± 0.06
		Placebo	0.97 ± 0.13	1.06 ± 0.45	0.97 ± 0.12
	%MSO	0.3 mg	57.17 ± 14.48		57.08 ± 14.57
		1.0 mg	56.08 ± 14.15		56.67 ± 14.06
		Placebo	56.50 ± 13.57		56.75 ± 14.07
Anodal tDCS	MEP	0.3 mg	0.95 ± 0.08	0.95 ± 0.13	1.00 ± 0.11
		1.0 mg	0.99 ± 0.16	0.88 ± 0.15	0.93 ± 0.13
		Placebo	1.00 ± 0.13	0.97 ± 0.15	0.99 ± 0.13
	%MSO	0.3 mg	56.83 ± 13.11		57.25 ± 13.07
		1.0 mg	57.08 ± 14.37		57.83 ± 14.83
		Placebo	56.75 ± 14.00		57.17 ± 13.82
PAS10	MEP	0.3 mg	0.94 ± 0.10	1.05 ± 0.40	1.04 ± 0.15
		1.0 mg	0.99 ± 0.10	0.86 ± 0.12	0.90 ± 0.08
		Placebo	1.01 ± 0.14	0.93 ± 0.18	0.97 ± 0.10
	%MSO	0.3 mg	57.08 ± 11.22		57.17 ± 11.63
		1.0 mg	57.75 ± 11.95		58.25 ± 11.93
		Placebo	56.67 ± 12.35		57.08 ± 12.38
PAS25	MEP	0.3 mg	0.92 ± 0.11	0.91 ± 0.21	0.95 ± 0.12
		1.0 mg	0.97 ± 0.10	0.97 ± 0.19	0.98 ± 0.14
		Placebo	1.01 ± 0.10	0.89 ± 0.15	0.94 ± 0.11
	%MSO	0.3 mg	56.83 ± 12.34		57.00 ± 12.45
		1.0 mg	57.17 ± 11.85		57.58 ± 11.95
		Placebo	57.25 ± 11.42		57.58 ± 11.42

Shown are the mean MEP amplitudes ± S.D. and stimulation intensity (percentage of maximum stimulator output, %MSO) means ± S.D. of baselines 1, 2 and 3. The intensity of TMS was adjusted to elicit MEPs with peak-to-peak amplitude of ~1 mV (baseline 1). A second baseline (baseline 2) was recorded three hours after varenicline or placebo intake to determine the impact of the drug on cortical excitability and adjusted if necessary (baseline 3). RM-ANOVAs revealed no significant differences between %MSO values and MEP amplitudes.