Prozac's position as the number one drug for depression could be under threat by a treatment which research claims is nearly twice as effective.
Trial studies on the effects of agomelatine, trade name Valdoxan, found that 77.7% of people taking the drug felt better, while only 68.8% of those taking Prozac reported a similar sensation.
The study appears to support earlier research claiming that the drug was nearly twice as effective in the first week than another antidepressant, venlafaxine.
Patients taking part in the study also reported fewer side-effects with agomelatine than with other treatments.
Lead researcher Professor Tony Hale, head of division of psychiatry at the University of Kent, said: "These results, showing better efficacy over Prozac, one of the most commonly prescribed antidepressants in the UK, add to the growing wealth of evidence supporting agomelatine as a new and important alternative for the treatment of depression."
The findings, based on 515 people with an average age of 42, who were followed for eight weeks, was presented at the European Congress of Neuropsychopharmacology in Istanbul on Tuesday.