The Effect of Nicotine Dependence on Psychopathology in Patients with Schizophrenia

Table 2

Hierarchical multiple regression between smoking severity and PANSS scores.

	Nonsmoker	Mild-moderate nicotine dependence	Severe nicotine dependence	N − M; Mean difference	N − S; Mean difference	M − S; Mean difference
Total PANSS score, mean, ^amean (s.d)	49.13	51.56	51.43				0.62	1.16	0.54
	50.33^a (10.28)	49.71^a (12.21)	49.17^a (9.22)
Positive subscale score, mean, ^amean (s.d)	8.54	9.65	9.76	−0.09	−0.04	0.05
	8.94^a (2.64)	9.04^a (3.09)	8.99^a (3.93)
Negative subscale score, mean, ^amean (s.d)	18.01	17.13	14.67	1.89	4.54	2.64
	18.41^a (5.67)	16.52^a (6.45)	13.87^a (4.48)
General psychopathology subscale score, mean, ^amean (s.d)	22.70	24.02	24.14	0.50	0.65	0.14
	23.42^a (4.13)	22.92^a (6.27)	22.77^a (7.07)

N, nonsmoker; M, mild-moderate nicotine dependence; S, severe nicotine dependence; and PANSS = Positive and Negative Syndrome Scale.
, , s.d = standard deviation.
^aMultivariate analysis of covariance with PANSS total score and subscale scores as dependent variables; covariates appearing in the model are evaluated at the following values: gender = 1.36, ethnicity = 1.70, drug and alcohol abuse = 1.12, income = 1.25, and atypical antipsychotic = 1.55. These tests are based on the linearly independent pairwise comparisons among the estimated marginal means and adjusted for multiple comparisons using Bonferroni familywise error correction.