A 68-year-old woman with a 3-year history of idiopathic Parkinson disease comes to the office with her husband for follow-up. The patient reports adequate control of motor symptoms with carbidopa-levodopa therapy but states that for the past month she has not spent time with her friends or participated in her church choir due to difficulty focusing. She sleeps restlessly most nights, resulting in daytime naps, and skips dinner because she is not hungry. The patient's medical history is otherwise noncontributory, and she takes no other medications. Vital signs are within normal limits. Physical examination is significant for reduced facial expressions and mild slowing on repeated finger tapping, but no significant tremors are noted. Posture and gait are normal. Which of the following is the best next step in management?
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This patient with Parkinson disease (PD) reports adequate control of motor symptoms but has developed nonmotor symptoms that cause impairment. Her month-long history of decreased interest and enjoyment of social activities (eg, no longer spending time with her friends), impaired concentration (eg, difficulty focusing in church choir limiting participation), sleep disturbance, fatigue, and loss of appetite is consistent with depression, a common complication of PD that can affect up to 50% of patients.
Depression may go unrecognized and undertreated in PD due to overlapping symptoms; for example, the PD symptoms of masked facies and bradykinesia are similar to the blunted affect and psychomotor retardation seen in major depressive disorder. In contrast, the presence of sadness and deliberate social withdrawal due to anhedonia (difficulty enjoying previously pleasurable activities) can help differentiate depression from apathy (decreased motivation to speak or act), a common finding in patients with PD that may occur with or without depression.
When PD is well controlled (ie, no tremors, normal gait), as in this patient, targeting symptoms of depression with antidepressants and/or cognitive-behavioral therapy is the most appropriate next step. Selective serotonin reuptake inhibitors are commonly used as first-line antidepressants because of their favorable adverse effect profile.
(Choice A) Adding a dopamine agonist would be appropriate if the patient's motor symptoms were not adequately controlled. A dopamine agonist is unlikely to relieve the patient's depression and may increase her risk for psychosis and impulse control disorders.
(Choice B) Although stimulants may be prescribed to treat fatigue in certain neurologic disorders, there is no established role for their use in the treatment of PD-related depression.
(Choice D) Antipsychotic agents have a role in the treatment of psychosis, a frequent complication of PD treatment. They are not first-line treatments for depression.
(Choice E) Carbidopa-levodopa can cause somnolence; however, this patient's daytime naps appear to be due to depressive symptoms because they are associated with restless sleep and anhedonia. Her current dose of carbidopa-levodopa is effectively controlling her motor symptoms, and dose reduction would risk worsening them.
Educational objective:
Depression is a common complication of Parkinson disease (PD) and is often undertreated because the two conditions have overlapping symptoms (eg, psychomotor slowing [bradykinesia], blunted affect [masked facies]). Patients with depression can be treated with antidepressant medication, psychotherapy, or both.