I've been on antidepressants for most of my life (I'm 65), mostly imipramine. Was on a 75mg maintenance dose but still having side effects (sweating, dry mouth, constipation) - dr suggested switching to nortriptylene, which might have fewer side effects as a lower dose is needed. A week and a half ago, stopped imipramine completely then started the next night with 40mg nortriptylene, going up to 50mg after 3 days. Felt AWFUL; doc suggested adding back 25mg imipramine for a week, then tapering down gradually over another week till I'm just on 50mg nortriptylene. I've been doing this for 4 days now and still feel horrible - did not expect to be plunged into this pit of depression - has anyone else had this experience? How long can I expect it to last??