Treatment of depression: an update on antidepressant monotherapy and combination therapy.

We analyzed the trends in product regimens used to treat depression to investigate whether there has been a shift in treatment patterns following the May 2008 launch of desvenalfaxine in the United States and the approval of an atypical antipsychotic as add-on therapy to antidepressants. Our analysis suggests that antidepressant monotherapy continues to be the most widely used drug treatment approach, accounting for 84 percent of depression treatment regimens. Antidepressant monotherapy is more prevalent among primary care physician-prescribed treatment regimens (92%) than psychiatry-prescribed regimens (73%). Combination treatment regimens have become increasingly more common as physician perception of disease severity increases, with antidepressant combination therapy accounting for eight percent, 17 percent, and 27 percent of treatment regimens for mild, moderate, and severe depression, respectively. The most commonly used agents in addition to an antidepressant in combination treatment regimens include another antidepressant (40% of combination regimens), an anxiety agent (40%), and/or atypical antipsychotics (18%). A trend analysis suggests that combination regimens that include an antidepressant plus an atypical antipsychotic, anxiety agent, or a prescription sleep aid comprise a greater share of combination regimens in 12 months ending May 2009 than they did in 12 months ending June 2008.