Scientists have suggested that drugs used to treat people with depression may actually be worsening the long-term causes of the condition.
A study published in the journal Progress in Neuro-psychopharmacology and Biological Psychiatry and conducted by Giovanni Fava and Emanuela Offidani from the University of Bologna shows that prolonged usage enhances the biochemical vulnerability to depression.
This, in turn, worsens its long-term outcome and symptomatic expression, and reduces the likelihood of a subsequent response to pharmacological treatment and the length of any symptom-free periods.
Following a study of databases art Medline, Cinahl, PsychInfo, Web of Science and the Cochrane Library, the expert found that although anti-depressants can be effective in treating depressive episodes, they are less effective at treating recurrent depression or preventing a relapse.
Side-effects such as withdrawal symptoms at discontinuation of use, the onset of tolerance and resistance phenomena and switch and cycle acceleration in bipolar patients were also observe by the scientists.
They subsequently recommended appraisal and testing of the oppositional model of tolerance, claiming it may produce "important insights" into the long-term treatment and achievement of enduring effects.