How Fast Are Antidepressants?

Background: For years, investigators havetried to determine the speed of onset of antidepressant drugs.Claims that particular drugs may produce a faster response inpatients than other agents have been made, but such claims havenever been confirmed.

Method: The authors reviewed reports fromstudies of the speed of onset of antidepressant therapies andother studies that revealed information on this topic. Wecompiled a list of factors that can affect the results of suchstudies and interpretations of study results. In addition, wereviewed literature concerned with methods of speeding upantidepressant responses.

Results: No antidepressant medication currentlyavailable has been shown conclusively to have a more rapid onsetof action than any other. However, some methods of augmentationmay have the potential to speed responses. Somatic therapies suchas electroconvulsive therapy, phototherapy, and therapeutic sleepdeprivation may be the fastest options available at this time.

Conclusion: All available antidepressantmedications are usually taken for several weeks before futureresponders will display a significant therapeutic benefit. If apatient does not show at least a 20% improvement within the first2 to 4 weeks of treatment, the treatment regimen should bealtered. For patients who do show early benefits from amedication trial, one can expect additional benefits to accrueover an 8- to 12-week period and to improve overall outcomecompared with those slower to respond. Future trials need toaddress methodological confounds, but a truly “fasterantidepressant” will probably require new neurosciencetechnology.