As Dr. Steven, a GP in South London with a special interest in mental health tells me, this shift that Katie reports after coming off antidepressants means the drugs have worked. "The recommendation for the duration of treatment for an antidepressant is six months from the point at which your depressed or anxious symptoms are under control. So once your symptoms are better or controlled, you continue the drug for six months. And after that time, if the person is still feeling well, I start to reduce their dose, and they can get rebound effects as the dose is reduced, but that should pass after a couple of weeks. The theory then is that you have overcome your episode of depression and your brain has learned that it needs to produce more of that chemical that you were giving it – ie. the brain adapts. In theory, the symptoms should remain under control." Dr. Steven is quick to point out, though, that depression is a variable illness and people who suffer from chronic depression or chronic anxiety, rather than episodes of it, should take the medication long-term. "Some people will experience a depressive episode and then overcome it; they may not be depressed again for several years. But other people experience chronic depression and they rely on a drug to increase their levels because they are naturally low producers of serotonin." As far as he is aware, there are no increased side-effects or issues with taking antidepressants for life if you are a person who suffers with chronic mental ill health.