All data were checked and cleaned before analyses. First, descriptive statistics and exploratory group comparisons were computed using Statistica 8.0 (StatSoft, 2008). SPSS Version 17.0 (SPSS Inc., 2008) was used for all other analyses. Depending on variable type and normality of score distributions, t-tests, ANOVAs, or chi-square tests were used to ascertain differences between the AD and control groups. For all ANOVAs, the assumptions of normal distributions, homogeneity of variance, independent observations, and interval measurement scales were met, thereby reducing the risk of Type I errors (Edenberg et al., 2005).
