Management of Dual Diagnosis of Parkinson's Disease and a Mental Health Disorder

Jasmine Carpenter, PharmD, BCPS; Adepeju Awodipe, PharmD; Wendy Brown, PharmD, BCACP


US Pharmacist 

In This Article

Abstract and Introduction


Mental health disorders are frequently seen in patients with Parkinson's disease (PD), possibly as a result of the complex imbalance of neurotransmitters in both disease states. This imbalance poses various treatment challenges, such as the exacerbation of both disease states and drug interactions between the medications used to treat PD and mental health disorders. Owing to these challenges, mental health disturbances in PD patients often go untreated. By assisting with ruling out causative medications and underlying disease states, simplifying antiparkinsonian regimens, and recommending antipsychotics, the pharmacist can help ensure that both of these disease states are adequately treated.


Parkinson's disease (PD), which impacts millions of people worldwide, is a neurodegenerative disorder involving the deterioration of motor, mental, and functional skills.[1] This degenerative decline increases mortality rates and negatively affects patients' quality of life. Motor movement disorders are heavily emphasized as cardinal signs of PD; however, nonmotor manifestations such as depression, anxiety, and psychosis are major concerns that must be addressed in this patient population.

Mental health (MH) abnormalities are common in PD; more than 60% of patients have one or more psychiatric symptoms.[2] Of these abnormalities, depression is the most common neuropsychiatric disturbance in PD, with reported rates of 20% to 90%.[3] Besides depression, patients with PD also experience psychosis, impulse-control disorders, mania, and sleep disturbances. The origins of MH disorders in this population have been attributed to both the underlying pathophysiology of PD and the adverse effects of antiparkinsonian drug therapy. These origins more likely lie at the neurotransmitter level and involve the complex interactions between dopamine, acetylcholine, and serotonin.[3] This poses a significant treatment challenge, given the dopaminergic, anticholinergic, and central nervous system (CNS)–acting medications used to treat both of these disease states. The object of this article is to outline the major difficulties encountered when providing medication treatment for patients with a dual diagnosis of PD and an MH disorder, as well as to proffer treatment recommendations and considerations.