Perceived Treatment Status of Fluctuations in Parkinson Disease Impacts Suicidality

Abstract

Objective: On/off motor fluctuations in Parkinson disease (PD) can be associated with extreme mood fluctuations and severe dysphoria. The impact of these affective symptoms may be overlooked in the treatment of motor fluctuations. Our goal was to examine the relationship between motor fluctuations, their treatment status, and suicidality in PD participants.

Methods: We analyzed data from the Methods of Optimal Depression Detection in Parkinson's Disease (MOOD-PD) study of 223 individuals with PD. Suicidality was measured using items from four depression scales: Hamilton Depression Rating Scale (HAM-D-17); Montgomery-Åsberg Depression Rating Scale (MADRS); Inventory for Depressive Symptomatology (IDS-C); and the self-rated Beck Depression Inventory (BDI). Multivariable Poisson regression analyses tested whether self-reported motor fluctuations and their treatment status were associated with suicidality while controlling for recognized risk factors.

Results: Thirty-seven participants (16.6%) self-reported suicidality and 89 (39.5%) self-reported motor fluctuations, of whom 21 (23.6%) perceived their fluctuations as untreated. Participants reporting untreated motor fluctuations more frequently had a current depressive disorder (p < 0.001) and endorsed suicidality (p = 0.006) than participants with treated or no fluctuations. They also had significantly higher total scores on the HAM-D-17, MADRS, IDS-C, and BDI depression scales (p < 0.001 for each). Regression analyses showed significant associations between untreated motor fluctuations and higher scores on suicide questions extracted from the HAM-D-17, MADRS, and IDS-C (p < 0.01 for each).

Conclusions: PD patients with untreated motor fluctuations are at increased risk for suicidal thoughts and should be monitored for mood changes as treatment is adapted.

Keywords: Parkinson disease; depression; fluctuations; suicide.

Figure 1. Comparison of participants with self-reported fluctuations based on perception of treatment

Participants perceiving untreated fluctuations (UF group) score higher on all three clinician-rated scales of depression (HAM-D-17, MADRS, IDS-C) and a self-rated scale of depression (BDI). However, they do not report worse quality of life (PDQ-8) or more severe impairment in ADL (UPDRS-II, measured “off” medication). They also do not exhibit worse neurologist-rated motor impairment (UPDRS-III, measured “on” medication). P-values derived from Mann-Whitney U tests. NS. = not significant. ** = p < 0.01.

Figure 2. Perceived untreated fluctuations are associated with worse depression but not worse quality of life

Depression score (A, C) or quality of life score (B, D) was linearly modeled based on either impairment in ADL (UPDRS-II, measured “off” medication) or neurologist-rated motor impairment (UPDRS-III, measured “on” medication). P-values derived from non-parametric analysis of covariance. All other scales of depression (HAM-D-17, IDS-C, and BDI) were also significantly higher in UF group (see supplemental table 2 for smoothing parameters and p-values for all depression scales).