Medicinal Cannabis for Parkinson's Disease: Practices, Beliefs, and Attitudes Among Providers at National Parkinson Foundation Centers of Excellence

Abstract

Background: Legalization of the medical use of cannabis for Parkinson's disease (PD) has bypassed the traditional drug-approval process, leaving physicians with little evidence with which to guide patients.

Objective: The goal of this study was to gather data on the cannabis-related prescribing practices and views regarding potential risks and benefits of cannabis among experts caring for patients with PD.

Methods: An anonymous, 73-item online survey was conducted through an online service (SurveyMonkey) and included neurologists at all National Parkinson Foundation Centers of Excellence.

Results: Fifty-six responders represented centers across 5 countries and 14 states. 23% reported some formal education on cannabis. Eighty percent of responders had patients with PD who used cannabis, and 95% were asked to prescribe it. Fifty-two percent took a neutral position on cannabis use with their patients, 9% discouraged use, and 39% encouraged it. Most believed that the literature supported use of cannabis for nausea (87%; n = 48), anxiety (60%; n = 33), and pain (86%; n = 47), but responses were divided with regard to motor symptoms. Most respondents expected that cannabis would worsen motivation (59%; n = 32), sleepiness (60%; n = 31), and hallucinations (69%; n = 37). In addition, most feared negative effects on short-term memory (75%; n = 42), long-term memory (55%; n = 31), executive functioning (79%; n = 44), and driving (96%; n = 54). Although many did not believe that cannabis should be recreational (50%; n = 28), most believed that it should be legalized for medicinal purposes (69.6%; n = 39).

Conclusions: This study provides data on the cannabis-related practices, beliefs, and attitudes of expert PD physicians. There is a lack of consensus that likely reflects a general knowledge gap and paucity of data to guide clinical practice.

Keywords: Parkinson's disease; cannabis; marijuana.

Figure 1

Source of Information on Cannabis. The majority of responders selected more than one source from which they obtained information to formulate opinions/beliefs about cannabis. Medical literature and personal experience were the most frequent sources of information. It is worth noting that, even at centers of excellence, there are physicians who describe their source of information as media, friends, and personal opinion. CME indicates continuing medical education.

Figure 2

Expected Effect of Cannabis by Symptom. Physicians were asked about the extent to which they expected cannabis would improve or worsen the following Parkinson's disease‐related symptoms: “improve” included the responses “much improved” and “little improved”; “worsen” included the responses “much worse” and “a little worse”; and “no effect” represented the response “no effect.” The majority of physicians expected that cannabis would lead to improvement in appetite, pain, nausea, and anxiety. Some positive effects also were expected for tremor, rigidity, and dyskinesias. The majority of physicians expected that cannabis would worsen fatigue, motivation, sleepiness, balance, forgetfulness, and hallucinations.

Figure 3

Beliefs About Policy. On average, physicians agreed that cannabis should be taught in medical schools. There was a tendency toward agreement that the status as a Schedule I (Sch I) substance should be reclassified. Most physicians did not feel strongly that cannabis should be made recreational, but many believed it should be allowed to be prescribed for medicinal purposes.