Table 1.

Summary of participant demographics means (SD)

	Healthy Controls	Pre-manifest HD	Group Difference
N	20	20	n.s.
Age (years)	50.8 (12.8)	46.2 (12.8)	p = 0.27
Gender (M:F)	8:12	6:14	p = 0.51
Handedness (R:L)	20:0	19:1	p = 1.0
Apathy Evaluation Scalea	27.6 (6.4)	27.4 (5.7)	p = 0.94
Dimensional Apathy Scale – totalb	22.6 (6.7)	19.7 (8.3)	p = 0.29
- Executive	5.7 (3.4)	4.35 (4.1)	p = 0.17
- Initiation	8.4 (3.3)	7.20 (3.6)	p = 0.22
- Emotional	8.5 (3.0)	8.15 (3.6)	p = 0.99
Hospital Anxiety and Depression Scalec
- Anxiety	5.00 (3.5)	4.75 (3.2)	p = 0.84
- Depression	2.95 (2.8)	2.15 (2.4)	p = 0.28
Montreal Cognitive Assessmentd	27.3 (1.9)	27.2 (2.4)	p = 0.83
Hopkins Verbal Learning Test – R
- Total recall	27.0 (3.2)	26.6 (4.3)	p = 0.76
- Delayed recall	9.00 (2.2)	8.33 (2.2)	p = 0.13
- Discrimination index	10.5 (2.0)	10.8 (1.7)	p = 0.58
Symbol Digit Modalities Test	56.6 (12.4)	53.6 (13.2)	p = 0.48
CAG repeats	N/A	41.3 (1.9)	N/A
		[38–45]
Total functional capacity	N/A	12.9 (0.3)	N/A
		[12–13]
Disease burden score	N/A	254 (82.7)	N/A
		[147–435]
Total motor score (UHDRS)e	N/A	1.35 (0.44)	N/A
		[0–4]

n.s., not significant

^aRange from 18 to 72. Proposed cutoff scores for apathy in HD are >40³⁴ or >41.³⁵

^bProposed cutoff score for apathy >28.5.³⁶

^cProposed cutoff score of >8 for each of the depression and anxiety subscales.³⁷

^dCutoff <26.

^eTotal motor score (on the Unified Huntington’s Disease Rating Scale) has a maximum of 124.