Final answer:
A 60-year-old with depressive syndrome and memory issues likely had depression-related cognitive impairment, as indicated by improved mood and cognition after antidepressant treatment with trazodone.
Step-by-step explanation:
The diagnosis for a 60-year-old with a depressive syndrome who was experiencing memory problems, confusion about the date, difficulty with tasks like serial sevens, and spelling backwards is likely a depression-related cognitive impairment. This is supported by the observation that both mood and cognition improved after treatment with trazodone, which is an antidepressant medication. When faced with memory issues and other symptoms like difficulty managing budgets and mood changes, it is important to consider both mood disorders such as depression and neurological conditions. However, since the cognition improved with the treatment of depression, the memory problems and cognitive issues were more likely due to the depressive syndrome rather than a primary neurocognitive disorder like Alzheimer's disease.