| CBI subscale | NPI subscale | r | UPDRS (I and II) subscale | r | PDQ-39 subscale | r | UPDRS (III) subscale | r |
| Memory | – | – | Intellectual impairment | 0.56 | Cognitions | 0.38 | – | |
| Orientation and attention | – | – | Intellectual impairment | 0.54 | Cognitions | 0.58 | Motor score | 0.28 |
| Everyday skills | – | – | Activities of daily living | 0.45 | Activities of daily living | 0.42 | Motor score | 0.30 |
| Self-care | – | – | Activities of daily living | 0.58 | Activities of daily living | 0.66 | Motor score | 0.44 |
| Mood | Depression | 0.44 | Depression | 0.36 | Emotional well-being | 0.50 | – | |
| Beliefs | Hallucinations | 0.58 | Thought disorder | 0.40 | – | – | – | |
| Challenging behaviour | – | – | – | – | – | – | – | |
| Disinhibition | Disinhibition | 0.38 | – | – | – | – | – | |
| Eating habits | – | – | – | – | – | – | – | |
| Sleep | Night-time behaviour | 0.31 | – | – | – | – | Motor score | 0.28 |
| Stereotypic and motor behaviour | – | – | – | – | – | – | – | |
| Motivation | Apathy | 0.52 | Motivation/initiation | 0.48 | – | – | Motor score | 0.26 |
| Insight/awareness | – | – | – | – | – | – | – |
Highest correlations significant at the 0.01 level are shown.
CBI, Cambridge Behavioural Inventory; NPI, Neuropsychiatric Inventory; PDQ-39, Parkinson's Disease Questionnaire; UPDRS, Unified Parkinson’s Disease Rating Scale.