Disinhibition is largely caused by frontotemporal damage and presents as one of the most significant sources of distress in caregivers for patients with neurodegenerative diseases. The Neuropsychiatric Inventory-Questionnaire (NPI-Q) was developed to assess neuropsychiatric and psychopathological symptoms, such as disinhibition, amongst patients with neurodegenerative disorders. Furthermore, the NPI-Q provides a rating scale for the severity as well as the subjective distress experienced by the patient (as rated by the caregiver). Our team also routinely assesses the caregiver’s distress surrounding the disinhibition. The Texas Functional Living Scale (TFLS) is a measure of functional independence that utilizes simulated activities of daily living, including medication, schedule, and financial management tasks. The current study explored the relationship between caregiver-reported disinhibition, including severity and related perceived patient and reported caregiver distress, and the functional decline as measured by the TFLS.

The study cohort consisted of 256 individuals who have undergone comprehensive neuropsychological assessment in an outpatient community neurology clinic and completed both the TFLS and had a caregiver complete the NPI-Q. In order to examine the relationship between the presence of caregiver endorsed disinhibition and functional decline, an independent t-test was performed. The relationships between caregiver endorsed disinhibition severity, perceived patient distress secondary to disinhibition, reported caregiver distress secondary to disinhibition, and overall functional decline were assessed using three one-way ANOVAS.

Of the 256 patient and caregiver dyads included in the sample, 89 caregivers endorsed the presence of disinhibition. Of the 89 caregivers who endorsed the presence of disinhibition, the mean severity of disinhibition was 1.84 (SD = .79), on a 1 to 3 scale. The mean caregiver distress secondary to disinhibition was 2.76 (SD = 1.32), on a 0 to 5 scale, while the perceived distress for the patient secondary to disinhibition as rated by the caregiver was 1.73 (SD = .89), on a 0 to 5 scale. Functional decline was not found to significantly statistically differ between patients whose caregivers endorsed the presence of disinhibition and those whose caregivers did not (p = .480). Caregiver reported disinhibition severity, perceived distress for the patient secondary to disinhibition, and caregiver distress were also not statistically significantly associated with functional independence as measured by overall TFLS scores (all p >.05).

Subjective disinhibition severity and distress for the patient and caregiver did not provide insight into a patient’s functional independence. Further analysis of NPI-Q items may offer insight into the utility of caregiver endorsement of neuropsychiatric and psychopathological symptoms in understanding the patient’s current level of functional independence in addition to potentially elucidating relationships between specific symptom endorsements and functional independence.