Scores on questionnaires at baseline and change scores (mean, SD) at 12 months' follow-up for the subthalamic nucleus and control groups
| Questionnaire | Subthalamic nucleus | Control | p Values | Cohen's d |
| Montgomery Asberg Depression Rating scale | 6.8 (4.6) | 5.5 (4.5) | ||
| Change score | 0.3 (5.9) | −2.0 (3.7) | 0.03 | −0.5 |
| POMS depression | 5.7 (6.1) | 4.9 (5.5) | ||
| Change score | −0.3 (5.3) | −0.5 (4.0) | 0.70 | −0.1 |
| POMS anger | 4.3 (4,4) | 4.0 (4.6) | ||
| Change score | −0.2 (4.8) | 0.6 (4.0) | 0.57 | 0.2 |
| POMS fatigue | 8.2 (5.6) | 6.7 (5.8) | ||
| Change score | −0.5 (6.1) | 0.7 (4.3) | 0.96 | 0.3 |
| POMS vigour | 11.8 (4.3) | 10.9 (4.0) | ||
| Change score | −1.0 (4.1) | 0.2 (3.1) | 0.22 | −0.3 |
| POMS tension | 9.3 (5.2) | 6.5 (4.5) | ||
| Change score | −2.6 (4.7) | −0.6 (3.1) | 0.09 | 0.5 |
| PANAS positive affect | 33.2 (9.1) | 30.5 (11.7) | ||
| Change score | −1.5 (10.1) | 2.1 (8.2) | 0.19 | −0.4 |
| PANAS negative affect | 20.6 (11.6) | 16.0 (11.1) | ||
| Change score | −3.6 (10.9) | −0.1 (7.9) | 0.23 | 0.3 |
| DEX self | 20.9 (10.6) | 17.8 (11.3) | ||
| Change score | −1.1 (9.8) | 0.5 (6.8) | 0.76 | 0.2 |
| DEX proxy | 19.4 (11.9) | 18.0 (12.3) | ||
| Change score | 0.9 (10.6) | −1.6 (9.3) | 0.02 | −0.3 |
| MAC self | 76.5 (10.9) | 74.2 (13.0) | ||
| Change score | −2.7 (9.1) | −1.5 (10.4) | 0.29 | 0.1 |
| MAC proxy | 76.7 (13.5) | 76.7 (11.3) | ||
| Change score | −4.0 (11.0) | −4.6 (10.3) | 0.60 | −0.1 |
| Parkinson's Quality of Life | 101.2 (20.8) | 85.3 (23.3) | ||
| Change score | −16.0 (21.6) | −0.1 (14.6) | 0.02 | 0.9 |
| CES-d | 13.8 (7.4) | 13.7 (7.7) | ||
| Change score | −0.0 (7.3) | −0.2 (5.2) | 0.19 | 0.0 |
| NPI delusions | 0.2 (1.2) | 0.0 (0.0) | ||
| Change score | 0.2 (1.2) | −0.1 (0.7) | 0.77 | −0.3 |
| NPI hallucinations | 0.1 (0.5) | 0.0 (0.2) | ||
| Change score | 0.0 (0.5) | 0.2 (1.0) | 0.03 | 0.3 |
| NPI agitation/aggression | 0.4 (1.4) | 0.3 (0.8) | ||
| Change score | 0.0 (1.6) | 0.1 (0.9) | 0.63 | 0.1 |
| NPI dysphoria | 1.2 (1.9) | 0.9 (1.3) | ||
| Change score | 0.0 (2.2) | 0.1 (1.2) | 0.27 | 0.1 |
| NPI anxiety | 0.6 (1.4) | 0.6 (1.5) | ||
| Change score | −0.1 (1.8) | 0.2 (1.5) | 0.72 | 0.2 |
| NPI euphoria | 0.0 (0.0) | 0.00 (0.0) | ||
| Change score | −0.1 (0.5) | 0.0 (0.2) | 0.13 | 0.3 |
| NPI apathy | 1.0 (1.9) | 0.9 (1.8) | ||
| Change score | 0.2 (2.0) | 0.0 (1.6) | 0.99 | −0.1 |
| NPI disinhibition | 0.5 (1.1) | 0.1 (0.5) | ||
| Change score | 0.3 (1.3) | 0.1 (0.8) | 0.46 | −0.2 |
| NPI irritability/lability | 1.0 (1.7) | 0.8 (1.7) | ||
| Change score | 0.4 (2.1) | −0.2 (1.0) | 0.30 | −0.4 |
| NPI aberrant motor behaviour | 0.4 (1.5) | 0.2 (0.9) | ||
| Change score | 0.1 (1.9) | 0.0 (1.0) | 0.69 | −0.1 |
| NPI sleep disorder | 2.6 (2.1) | 2.9 (2.9) | ||
| Change score | 0.1 (2.7) | −0.6 (2.3) | 0.20 | −0.2 |
| NPI appetite change | 2.0 (2.9) | 0.8 (2.3) | ||
| Change score | 0.2 (3.9) | 0.0 (2.7) | 0.97 | −0.1 |
| Negligence | 0.3 (1.2) | 0.1 (0.4) | ||
| Change score | 0.1 (1.2) | −0.1 (0.4) | 0.96 | −0.2 |
| Sexual changes | 1.1 (2.5) | 0.9 (2.3) | ||
| Change score | 0.1 (2.5) | 0.5 (3.1) | 0.46 | 0.1 |
| Language/speech changes | 5.0 (3.6) | 3.4 (2.4) | ||
| Change score | 1.2 (3.4) | 0.5 (2.7) | 0.20 | −0.1 |
| Cognitive changes | 2.9 (3.3) | 1.8 (2.1) | ||
| Change score | 1.3 (3.3) | 0.2 (1.6) | 0.12 | −0.4 |
The effect size (Cohen d) is negative if in the direction of decline in the STN group, or positive if it is in the direction of improvement.
p Values are from two-tailed ANOVAs corrected for age, years of education, amount of dopaminergic medication and disease duration. p Values for Neuropsychiatric Inventory (NPI) and additional items are from Mann–Whitney tests (two-tailed) and are not corrected for covariates.
CES-d, Center for Epidemiologic Studies-Depression scale; DEX, Dysexecutive Syndrome Questionnaire; MAC, memory assessment clinic rating; PNAS, Positive Negative Affect Scale; POMS, Profile of Mood States.