Depression is a severe mental illness characterised by a persistent low mood and loss of all interest and pleasure, usually accompanied by a range of symptoms such as appetite change, sleep disturbance and poor concentration. The predominant treatment options for depression are drugs and psychological therapies, but antidepressant drugs are the most common treatment for moderate to severe depression. Fluoxetine, one of the first new generation antidepressants, is an extremely popular drug treatment for depression. However, findings from studies comparing fluoxetine with other antidepressants are controversial. In this systematic review, the efficacy and tolerability of fluoxetine was compared with other antidepressants for the acute treatment of depression.
In May 2012 we searched, in a wide-ranging way, for all the useful studies (randomised controlled trials, or RCTs) we could find which compared fluoxetine with any other antidepressant in treating people with depression. One hundred and seventy-one RCTs were included, with 24,868 people in the analyses. Combining the results from all the trials, fluoxetine was similarly effective, but better tolerated, than older generation (tricyclic) antidepressants. In comparison with other new generation antidepressants, important differences in efficacy and in tolerability were found between fluoxetine and some of the antidepressants, for example, fluoxetine was less effective than sertraline and mirtazapine but better tolerated than reboxetine. These differences might have a clinical impact in everyday practice. However, when interpreting these differences it is important to bear in mind that the studies were short in duration (eight weeks or less) and that the average size of each trial was small (each included around 100 people). Moreover, most of the included studies were sponsored by drug companies, which could potentially have led to an overestimation of treatment effect. As a consequence, it is difficult to draw clear, clinically meaningful conclusions. More reliable information is needed about the respective safety profiles of antidepressants.