Table 3 lists the means and standard deviations for the disinhibitory symptom counts as well as the Pearson correlations among counts included in the factor analysis. By both a scree plot and a traditional eigenvalue criterion, only one factor was evident with an eigenvalue of 2.55 that accounted for 42% of the variance. The eigenvalue difference between the first and second factors was 1.56 and all other factors comprised <17% of the variance. The component loadings for each of the symptom counts were as follows: ADsx, 0.41; ADHDsx, 0.65; ASPDsx, 0.82; CDsx, 0.87, DDsx, 0.56, and NS scores, 0.47. The comparatively low factor loading for ADsx may be explained by the restricted range of AD symptoms. Subjects could only have within the range of 3 to 7 symptoms and over 80% had ≥6 symptoms.
