Table 3. Linear Regression Analyses Using Each Neuropsychological Test Score and the Personality Assessment Inventory as the Outcome Variable in Separate Adjusted Models¹.

	Essential Tremor vs. Healthy Controls		Essential Tremor vs. Parkinson’s Disease		Parkinson’s disease vs. healthy controls
	β	p	β	p	β	p
Global cognitive performance
Mini-Mental State Examination	0.221	0.097	–0.119	0.281	0.367	0.004
Executive function and attention
Direct Digit Span subtest from the WAIS-III	0.012	0.929	–0.120	0.251	0.063	0.638
Indirect Digit Span subtest from the WAIS-III	0.216	0.086	–0.058	0.618	0.179	0.164
Coding-Digit Symbol subtest from the WAIS-III	0.370	<0.001	0.018	0.831	0.343	<0.001
Similarities subtest from the WAIS-III	0.285	0.013	0.029	0.734	0.208	0.054
Trail-making Test, B – A	–0.323	0.017	0.171	0.195	–0.417	0.002
Stroop Color–Word Trial (interference effects)	0.118	0.422	–0.108	0.390	0.258	0.068
Wisconsin Card Sorting Test (errors)	0.108	0.389	0.050	0.690	0.049	0.697
Wisconsin Card Sorting Test (perseverations)	0.103	0.440	0.055	0.683	–0.018	0.891
Tower of London (time of execution in seconds)	–0.180	0.137	0.079	0.519	–0.266	0.043
Frontal Assessment Battery	0.318	0.011	–0.033	0.789	0.391	0.003
Visuospatial ability
Benton Judgment of Line Orientation Test	0.092	0.453	–0.216	0.063	0.187	0.176
Hooper Visual Organization Test	0.183	0.157	–0.193	0.114	0.366	0.002
Verbal memory
WMS-III Word List
Learning	0.170	0.177	–0.079	0.472	0.176	0.154
Immediate recall	0.265	0.044	0.135	0.247	0.038	0.783
Delayed recall	0.279	0.026	0.065	0.576	0.174	0.187
Delayed recognition	0.312	0.013	0.150	0.293	0.221	0.128
Visual memory
Brief Visuospatial Memory Test-Revised
Learning trials	0.388	0.002	0.002	0.983	0.468	<0.001
Delayed recall trial	0.380	0.003	0.002	0.989	0.430	<0.001
Recognition trial	0.186	0.198	–0.208	0.123	0.318	0.018
Language
Boston Naming Test	0.297	0.013	–0.132	0.222	0.376	0.003
Category-cued Word Fluency	0.079	0.534	0.029	0.780	0.116	0.336
Controlled Oral Word Association Test	0.270	0.019	0.070	0.479	0.166	0.174
Personality and Psychopathology
Personality Assessment Inventory
Somatic concerns	–0.223	0.093	–0.154	0.200	–0.051	0.694
Anxiety	–0.230	0.033	–0.220	0.064	–0.022	0.874
Anxiety related disorders	–0.123	0.311	–0.274	0.028	0.209	0.154
Depression	–0.309	0.003	–0.134	0.186	–0.057	0.604
Mania	–0.069	0.636	–0.194	0.153	0.041	0.791
Paranoia	–0.114	0.413	–0.196	0.147	0.174	0.248
Schizophrenia	–0.068	0.591	–0.256	0.026	0.296	0.039
Borderline features	–0.073	0.559	–0.341	0.008	0.284	0.049
Antisocial features	–0.230	0.081	–0.086	0.516	–0.116	0.405
Alcohol problems	–0.120	0.421	–0.093	0.495	0.036	0.828
Drug problems	0.199	0.179	–0.082	0.578	0.299	0.044

Significant values are in bold font.

¹Adjusted for age, sex, years of education, medications that potentially affect cognitive function, total number of medications, and 17-item Hamilton Depression Rating Scale total score.