(PSYCHIATRIC TIMES) - Approximately 32 to 35 million adults in the United States have an episode of major depression sometime during their lifetime, and many of them do not respond to initial treatment.1 The results of an analysis undertaken by Fava and Davidson2 suggest that between 29% and 46% of depressed patients fail to respond fully to antidepressant treatment of adequate dose and duration; about 15% of patients fail to respond to multiple treatment trials.3 Fagiolini and Kupfer4 have suggested that patients with treatment-resistant depression (TRD) may represent a biologically unique subtype of depressed patients. Unfortunately, the chances for full recovery diminish the longer a patient remains depressed—a fact that lends a sense of urgency for appropriate therapy.5
Before discussing the effectiveness of individual agents in TRD, it is important to review recent evidence regarding the principles of using these agents to maximize the chance of a response.6-9 Some of the most salient findings from the STAR*D trial on this topic are summarized in Table 1.
The standard strategy for managing patients who are depressed includes an adequate clinical trial; when the response is unsatisfactory, the clinician’s options are:
• Switch to another antidepressant
• Combine a second antidepressant with the first
• Add a second drug that is not approved as an antidepressant
• Start psychotherapy
Antidepressants can be grouped into 6 major categories: tricyclic antidepressants (TCAs), SSRIs, serotonin norepinephrine reuptake inhibitors (SNRIs), monoamine oxidase inhibitors (MAOIs), serotonin neurotransmitter (5-HT2)-receptor antagonists (eg, nefazodone, trazodone), and novel agents (eg, mirtazapine, bupropion). If a patient fails to respond to one antidepressant class, it makes sense (at least conceptually) to switch to another, although most guidelines acknowledge that 2 failed trials of SSRIs may be justifiable before switching classes.7,8 When examining switching studies, be certain that the reason for switching was a failure to respond to an adequate antidepressant trial rather than a lack of tolerability, as these are fundamentally different issues.
The concept of switching classes of antidepressants is only as valid as the theoretical basis by which the antidepressants are grouped. As noted, some treatment guidelines allow 2 SSRI trials before switching classes. For example, in a study by Thase and colleagues,10 58 patients failed
For full article, please visit: