The package inserts for antidepressants warn that the drugs increase the risk of suicide. For fluoxetine, the Danish package insert says that suicidal thoughts “may increase when you start taking antidepressants because the medication takes a while to work, often around 14 days, but sometimes longer;” and that “clinical studies have shown that there was an increased risk of suicidal behaviour in adults under the age of 25 with psychiatric disorders.”
This information is not entirely accurate. The effect of the medicines does not start after a given number of days but comes very gradually. Even after six weeks, which is the trial duration in most trials, the difference in depression symptoms between active substance and placebo is so small that it is less than what psychiatrists consider clinically relevant. Therefore, many so-called critical psychiatrists believe the medication does not actually have any beneficial effect on depression.
It is misleading to say that suicidal thoughts may increase at the start of treatment. They can come at any time, especially at times of dose changes, either increases or decreases, which the US Food and Drug Administration (FDA), but unfortunately not the Danish Medicines Agency, therefore warns about.