How can i tell if a depression is situational or really does need medication. diagnosed with depression 2 years ago after loss of partner , home ?

Time for a Trial: I assume that you have been struggling with depression most of the two years since you were diagnosed. The distinction between situational and endogenous or "biological" depression is not as complete as one might think--both often are involved. At this point I suspect what matters most to you is would medication help? After two yrs I recommend you consult a psychiatrist and find out. Good luck!

You can't.: It tends to take expertise, though sometimes it is obvious. Consider the possibility of a need for treatment if you are limited or bothered by the depressive symptoms; if they tend to dominate or interfere with your life; if they prevent you from having other good feelings or experiences; if you can't seem to adapt or get past an experience that triggered them. Then see what a consultant says.

Does not matter: Depression that begins after life stressors (common) does not generally show any different biomarker patterns (i.e. CSF catechol. metabolites, functional neuroimaging) than spontaneous depression (rare). We do not differentiate the treatment-worthiness of depression based on whether there were precipitants or not. Please be willing to seek treatment with a doctor who listens also.