Prevalence of depression and receipt of antidepressant pharmacotherapy among patients with Parkinson’s disease: a national assessment of US office-based physician visits

Abstract

Background:

The prevalence of comorbid depression in patients with Parkinson’s disease (PD) is estimated to range from 17% to 25%, although up to 35% to 42% of patients with PD display clinically significant depressive symptoms. Untreated depression leads to a worsening course of PD, decreased quality of life, and increased mortality.

Methods:

Data were obtained from the US National Ambulatory Medical Care Survey (NAMCS) of office-based physician visits made in 2013 and 2014. For office visits with a diagnosis of PD (International Classification of Diseases, 9th Revision [ICD-9] code 332.0), the study measures included the rates of diagnosed depression (ICD-9 codes 296.2, 296.3, 300.4, or 311), recording of depression as a comorbidity, and prescribing of antidepressant pharmacotherapy. Analytic results were compared with those of a similar study that measured depression diagnosis (ICD-9 codes) and antidepressant prescribing, using NAMCS data for 1990–1995.

Results:

In 2013–2014, 29.8% of patients with PD were provided ≥1 antidepressant for any indication, triple the rate that was observed in 1990–1995 (8.6%). From 1990–1995 to 2013–2014, the percentage of patients with an ICD-9 code for comorbid depression increased from 4.1% to 8.3%, and the percentage with both an ICD-9 code and antidepressant pharmacotherapy increased from 3.2% to 7.2%. Of patients with an ICD-9 code for depression, 78.2% in 1990–1995 and 87.1% in 2013–2014 were prescribed antidepressant medication. In 2013–2014, 14.8% of patients with PD had recognized depression, measured by either ICD-9 code or NAMCS comorbidity indicator.

Conclusion:

In office-based physician visits made by US patients with PD, the rate of antidepressant prescribing for diagnosed depression more than doubled from 1990–1995 to 2013–2014. However, the 14.8% prevalence of recognized depression remains lower than that suggested by previous studies of PD. Further research is needed to assess the reasons for these findings and promote optimal physical and mental health among patients with PD.

Keywords::

• Parkinson’s disease
• depression
• antidepressant
• National Ambulatory Medical Care Survey

Disclosure

The authors report no conflicts of interest in this work.