Hi Maven
I think it may depend on the type of depression or other diagnosis that you have. There is a new therapy called magnetic stimulation therapy for depression and people do have scans to see if they are suitable for that. Also for ECT I think that scans are done for that too. The cost involved in having a MRI can be enormous as some people I see have already posted. Doctors also do not like to expose people to too much radiation which might be a reason against having that type of scan. Medication effectiveness can be sometimes checked by a blood test rather than a scan and how people respond in mood, thinking and actions. I think on an individual case to ask ones doctor if follow up tests or scans would be helpful for providing more information to help in diagnosis or further treatment why/why not might be reassuring to you. Maybe its a good idea of yours but the doctors haven't thought of it yet! Hope you get the answers you seek from your doctor.