A 79-year-old man with Parkinson disease for the past 3 years comes to the office due to poor appetite, weight loss, increased generalized weakness, "difficulty thinking," and impaired sleep over the past 4 months. The patient has become increasingly isolated as his functional abilities have declined and says, "I don't want to live like this anymore. I hope God takes my life already." He is still able to live alone but has stopped seeing his friends and no longer enjoys spending time with his family. The patient has no psychiatric history. He does not use tobacco or alcohol. His only medication is pramipexole. Temperature is 36.7 C (98 F), blood pressure is 144/88 mm Hg, pulse is 74/min, and respirations are 14/min. Examination shows right hand greater than left resting tremor; generalized muscle rigidity; and a slow, shuffling gait, none of which are new. On mental status examination, the patient's affect is blunted and his mood is depressed. He is oriented, states the months of the year backwards very slowly with 2 mistakes, and recalls 3 of 3 items in 5 minutes. Which of the following is the most likely explanation of the patient's new symptoms?

Question

A 79-year-old man with Parkinson disease for the past 3 years comes to the office due to poor appetite, weight loss, increased generalized weakness, "difficulty thinking," and impaired sleep over the past 4 months.  The patient has become increasingly isolated as his functional abilities have declined and says, "I don't want to live like this anymore.  I hope God takes my life already."  He is still able to live alone but has stopped seeing his friends and no longer enjoys spending time with his family.  The patient has no psychiatric history.  He does not use tobacco or alcohol.  His only medication is pramipexole.  Temperature is 36.7 C (98 F), blood pressure is 144/88 mm Hg, pulse is 74/min, and respirations are 14/min.  Examination shows right hand greater than left resting tremor; generalized muscle rigidity; and a slow, shuffling gait, none of which are new.  On mental status examination, the patient's affect is blunted and his mood is depressed.  He is oriented, states the months of the year backwards very slowly with 2 mistakes, and recalls 3 of 3 items in 5 minutes.  Which of the following is the most likely explanation of the patient's new symptoms?

Quizplus · Accepted Answer

This patient's depressed mood and associated symptoms of impaired sleep, appetite, energy, concentration, interest, and suicidality are consistent with major depressive disorder (MDD). Depression is the most common psychiatric disturbance seen in Parkinson disease (PD). MDD occurs in 10%-20% of patients with PD, and sub-syndromal depressive symptoms occur in up to half of patients. The diagnosis of MDD is difficult in patients with PD as blunted affect and psychomotor slowing seen in depression are similar to bradykinesia and masked facies seen in PD. The presence of depressed mood and anhedonia (inability to experience pleasure in previously enjoyed activities) can assist in diagnosis. In addition, this patient's hopelessness, suicidality, and temporal association of his mood changes with worsening neurovegetative symptoms make MDD more likely. (Choice A) Adjustment disorders are characterized by significant distress due to an identifiable stressor, within 3 months of the onset of that stressor. This diagnosis is not used if symptoms meet criteria for another psychiatric disorder. (Choice B) Commonly used treatments for PD include levodopa, dopamine agonists (eg, pramipexole, bromocriptine, ropinirole), and monoamine oxidase type B inhibitors (eg, selegiline). Although these medications may cause psychosis, none of them cause depression. (Choice C) Apathy is characterized primarily by a loss of motivation, more specifically a decreased motivation to speak or act. It is a common finding in patients with PD and may occur with or without depression. Apathy by itself would not explain this patient's depressed mood and other depressive symptoms. (Choice D) Although cognitive dysfunction and dementia are common in PD, this patient has prominent mood symptoms (which can include impaired concentration) and is not exhibiting marked deficits in executive functioning and memory impairment. (Choice F) Persistent depressive disorder (ie, dysthymia or dysthymic disorder) is characterized by depressed mood for 2 years, associated with 2 or more changes in sleep, appetite, energy, self-esteem, concentration, and hopelessness. Educational objective: Major depressive disorder may occur in up to 20% of patients with Parkinson disease (PD). Although the diagnosis of major depression may be difficult due to overlapping symptoms with PD, the presence of depressed mood, anhedonia, hopelessness, and/or suicidality often suggests major depression. References: Psychosis, apathy, depression and anxiety in Parkinson's disease. (http://www.ncbi.nlm.nih.gov/pubmed/22245219) Depression in Parkinson's disease. (http://www.ncbi.nlm.nih.gov/pubmed/21560065)

A 79-Year-Old Man with Parkinson Disease for the Past 3