Depression: Differential Diagnosis?

Obviously Major Depression is its own diagnosis. However, depression can also be a symptom of many neurological diseases (e.g. multiple sclerosis).
I’d appreciate it if all of you could list off all of the diseases you know where depression is a symptom.

Name any chronic disease – chances are, there is a correlation with depression. The most common ones with this association (probably because a lot of these happen to be the most common chronic diseases) are probably heart disease, cancer, diabetes, and HIV/AIDS. Degenerative neurological conditions and stroke also have a strong association with depressive symptoms.
However, going through and testing for all those possibilities if depression were the only symptom would be very low yield. Usually, what is always done when trying to make the diagnosis (in addition to basic labs such as chemistry and CBC) is a TSH level (hypothyroidism can be extremely similar to depression in terms of symptoms), and tests for reversible causes of dementia (B12, folate, liver function, sometimes RPR). Also, a very thorough history is essential, to get clues about possible factors/events that triggered the depression, and also exposure history or risk factors for any hidden medical conditions that may justify further tests.