Drug consumption in medication overuse headache is influenced by brain-derived neurotrophic factor Val66Met polymorphism

Table 2 Results of stepwise multiple regression analysis: BDNF polymorphism (G/G genotype) and BDI score (depressive symptoms) are the predictors of monthly drug number in MOH patients

Variable	Beta	t	P
BDNF gene	0.33	3.669	<0.0001
BDI	0.19	2.090	<0.04
MOH duration	0.12	1.242	0.22
Drug type	0.08	0.917	0.36
Gender	0.08	0.908	0.37
Employment	−0.07	−0.754	0.45
Current psychiatric diagnosis	0.05	0.532	0.60
Age of headache onset	−0.02	−0.167	0.87
Age	0.01	0.123	0.90

Significant predictors are in bold
Stepwise model summary: adjusted R² = 0.137, F_2,104 = 9.424, P < 0.0001, f² = 0.181
Stepwise model change statistics: first step, variable entered = BDNF gene, R² change = 0.118, F_1,105 to enter/to remove = 14.030, P < 0.0001, f² = 0.134; second step, variable entered = BDI, R² change = 0.036, F_1,104 to enter/to remove = 4.368, P < 0.04, f² = 0.037
MOH medication overuse headache, BDNF brain-derived Neurotrophic factor, BDI beck depression inventory

ISSN: 1129-2377