Relative treatment-resistant depression

Two major problems complicating the question of treatment-resistant depression are inappropriate diagnosis and inadequate treatment (355). Studies have found only a small proportion (< 15%) of newly diagnosed depressed patients receive adequate antidepressant treatment as defined by dose and duration criteria (356, 357). Hence, a substantial number of treatment-resistant cases are actually the result of inadequate therapy (i.e., relative resistance). For example, in the MacEwan and Remick (358) study, 70% of those defined as treatment-unresponsive achieved complete remission with an adequate trial of an HCA, MAOl, or ECT. Patients who do not receive sufficient benefit from a trial of one antidepressant now have the option of newer agents whose activity does not necessarily overlap with earlier generation compounds (e.g., SSRIs, venlafaxine, nefazodone). 

Treatment-resistant depression typically refers to an inadequate response to at least one antidepressant trial of adequate dose (superior to placebo in controlled clinical trials) and duration (e.g. 6-12 weeks). Treatment-resistant depression is a relatively common occurrence in clinical practice, with up to 50-60% of patients not achieving an adequate response following antidepressant treatment. Although the more traditional view of treatment resistance has focused on non-response, from the perspective of clinicians and patients, not achieving remission despite adequate treatment represents a significant challenge. In addition, response without remission has a potentially poor outcome, as residual symptoms are associated with poorer outcome and increased relapse risk. With this treatment approach in mind, inadequate response implies that the treatment has failed to achieve remission from the clinician s and patient s perspective, remission typically implies achieving a relatively asymptomatic state. ... 

TRD can best be conceptualized as occurring along a continuum rather than as an all or none phenomenon. Some patients have a relatively low level of therapy resistance, which can be easily handled in practice by straightforward clinical procedures other patients will follow a much more malignant course. From longitudinal studies (Keller et al. 1992), it is now clear that as many as 15% of patients with depression follow a long-term course and eventually become treatment resistant to almost all antidepressants. 

Nowadays, ECT is recommended for major depression, usually when other approaches have failed. However, some doctors quickly resort to it. Probably more than 100,000 patients a year in the United States are shocked. The majority are women, and many are elderly. Advocates of shock have resisted the creation or maintenance of state registers for shock treatment, so most of the data on the frequency of its use are relatively old. In California, for example, two-thirds of shock patients were reported to be women, more than half of whom were 65 or older (Department of Mental Health, 1989). Data (1989-1993) from Vermont concerning ECT showed that 77% of shock patients were female (W. Sullivan, personal communication, 1996). For all sexes, 58% were at least 65 years old, and 20% were at least 80 years old. During this time, one Vermont hospital, Hitchcock Psychiatric, shocked 35 women and 1 man who were 80 and older. Overall, the hospital shocked 112 women and 26 men during those 5 years. 

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