For twenty-five years I’ve accepted without question the standard teaching that SSRIs take 2 – 3 weeks to kick in and often longer. Then, due to a family situation, I actually went and looked it up, and discovered that the research doesn’t support that at all. It actually appears that they start having an effect within 1 – 2 weeks if they’re going to have an effect at all.
This meta-analysis showed that if Mirtazapine hasn’t kicked in within the fortnight, it’s very unlikely to do so later. This one, looking at SSRIs, has some nice little graphs (Fig 3) showing the same thing, and also identified that improvement starts in the first week and can continue for up to six weeks. This one has fewer helpful figures in the abstract but backs up the general idea. Just in case I end up using tricyclics or MAOIs for some unlikely reason, this study looked at some of the older drugs and found basically the same thing. This editorial has a summary of the research, though I think the above links cover the main points.
Very helpful; means that, if a tablet isn’t working, I’ll be able to recognise that earlier and move onto the next thing.