Differential Diagnosis

• Single most likely diagnosis
  • Adjustment disorder: This is the most likely diagnosis because the patient's symptoms of sadness, hopelessness, and restricted affect are directly related to his recent diagnosis of Parkinson's disease and its impact on his life, such as having to consider early retirement and no longer being able to play golf. These symptoms have developed within a short time frame after the diagnosis, which is consistent with an adjustment disorder.
• Other Likely diagnoses
  • Dysthymic disorder: Although less likely, dysthymic disorder could be considered if the patient's symptoms of sadness and hopelessness have been present for a longer period than indicated, as dysthymia is characterized by a chronic, low-grade depressive state.
  • Major depressive disorder: This could be a consideration if the patient's symptoms were more severe, including changes in sleep or appetite, social withdrawal, or feelings of guilt, which are not mentioned in the scenario.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Substance-induced mood disorder: Given the patient's recent start of carbidopa-levodopa therapy, it's crucial to consider the possibility that his mood symptoms could be induced by this medication, although this is less common.
• Rare diagnoses
  • Generalized anxiety disorder: While the patient expresses worry about his health problems' financial impact on his family, his primary symptoms are more indicative of a mood disorder related to his adjustment to Parkinson's disease rather than generalized anxiety. This diagnosis seems less likely based on the information provided.