2007, Number 6
Salud Mental 2007; 30 (6)
Pharmacogenetics of antidepressants
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Text ExtractionSince the serendipitous discovery of imipramine, in 1957, different classes of antidepressant drugs have been used to treat depressive syndromes. Although their efficacy is well established, still 30-40% of patients do not show a significant response (>50% reduction in baseline score on the Hamilton Rating Scale for Depression – HAMD) to therapeutic doses of antidepressant medications administered for 6-8 weeks of treatment, while 60-70% fail to achieve full remission (17-item HAMD<7) (Moncrieff and Kirsch, 2005). Partial remission has been associated with a higher recurrence, a greater functional impairment and a worse quality of live (Fava et al., 2002; Tranter et al., 2002). All antidepressants have a lag phase and it takes at least 3-4 weeks to observe the real effect of treatment administration (Quitkin et al., 1996). Such a delayed response may increase the patients’ suffering and the risk of suicidal behavior and early discontinuation of treatment. Patients have to stay in hospital for longer periods and this results in higher costs. Therefore early identification of responders to a specific antidepressant treatment would be of great usefulness both from a clinical and economical point of view. Unfortunately, in spite of some evidence concerning the predictive power of demographic characteristics, illness features and social factors (Esposito and Goodnick, 2003; Goodnick, 1996; Nierenberg, 2003), none of such variables could unequivocally be linked to treatment outcome and antidepressant choice is still based on a trial and error procedure.