Hi Claire
I have been working as a pharmacist for 5 years now and thought you might like to hear about the changes in antidepressant treatments times that have arisen in that time - it may explain the various times you have heard of.
It was always commonly accepted that the average treatment length for reactive depression (or a single episode of depression) should be a minimum of 18 months. However, several years ago, it became widely accepted that 6 months therapy was all that was required - this was based on a report from the medicines control agency. This is where the confusion sets in..... because what that report actually said was that therapy should be continued for 6 months AFTER remission had been achieved.
Depending on how someone responds to the therapy, and how quickly the doctor adjusts your dose for the right effect you could be looking anywhere between those 2 figures of 6-18months. In my experience, however, most doctors tend to plump for the 18month option - "just to be on the safe side"
As for coming off antidepressants........ Withdrawal is now recognised as a possibility, though it is by no means the norm. However, it can be extremely upsetting for the patient should it occur. The current recommended withdrawal times are as follows:
Length of time on treatment Reduction Period
under 2 months none needed
2 months plus minimum 4 weeks
4 yrs plus 6 months
sorry! I've dribbled on a bit
Anyway, hope it helps!