If I were seeing doctors for years and getting no relief, I would definitely change doctors and, ethically, doctors should be referring or consulting outside the practice when there is no improvement in conditions that are often responsive to psychotherapy and/or medication.
I have seen a psychiatrist and a psychologist in the same practice for years. They communicate with each other. I have been treated fo Bipolar II disorder with Lamictal for years, so I know it does not affect my liver enzymes. I have tried quite a number a AD for Magior Depression. They didn't work and/or elevated liver enzymes.
Have you considered seeing a psychologist? Many are able to assist people through their depressive states without the use of medications. Of course, one has to be careful about choosing a clinician. I have a friend who is a psychiatrist and has 1500 patients on her caseload. Many psychologists have 10 to 30 patients. Further, having therapy twice weekly with a knowledgeable psychotherapist can make a big difference. I will PM you with more details later.
There are different "types" of depression. All depressions are not the same. I.E. Major Depressive Disorder, Atypical Depression, Dysthymic Disorder. etc. Similar to, the different causes of liver disease. For example; A person who has chronic hepatitis B, needs hepatitis B treatment not hepatitis C treatment. The treatment must be appropriate to the type of depression the person suffers from.
Therefore...
1. You need a psychiatrist to diagnose the type of depression you are suffering from.
2. The doctor can decide among the group of antidepressant of meds that usually work for the type of depression.
3. You and the psychiatrist must find a med that works for your depression. Just because a med works for someone else doesn't mean it will work for you. Antidepressants must be tried until you find one that works for you and your depression.
Good luck!
Hector