27 The authors reported

that, cingulate hypometabolism may represent an important adaptive response to depression and failure of this response may underlie poor outcome.27 Impact of TRD TRD is associated with extensive use of depression-related and general medical services and poses a substantial economic burden. A naturalistic, retrospective Inhibitors,research,lifescience,medical analysis of medical claims data by Crown and colleagues found that treatment-resistant patients were at least twice as likely to be hospitalized (general medical and depression related) and had at least 12% more outpatient visits.15 FK866 in vivo treatment resistance was also associated with use of 1.4 to 3 times more psychotropic medications (including antidepressants). Patients in the hospitalized TRD group had over 6 times the mean total medical costs of non-TRD Inhibitors,research,lifescience,medical patients (US$ 42 344 versus US$ 6512) and their total depression-related costs were 19 times greater than those of patients in the comparison group (US$ 28 001 versus US$ 1455).15 These findings emphasize the need for early identification and effective long-term maintenance strategies for TRD. Approaches in the management of TRD General principles The general principles of the

management of TRD are outlined in Table I. Table I. General principles for the management of treatment-resistant depression. Antidepressant treatment strategies Increasing the Inhibitors,research,lifescience,medical dose of antidepressant Increasing the Inhibitors,research,lifescience,medical dose of antidepressant is a common strategy for patients who have not responded to an adequate trial with a selective serotonin reuptake inhibitor (SSRI).28 In patients who had not responded to fluoxetine 20 mg/day, Fava and colleagues showed that raising the dose of fluoxetine to 40 to 60 mg/day was significantly more effective than adding desipramine 25 to 50 mg/day

or lithium 300 to 600 mg/day29 No guidelines exist regarding the adequate duration of higher-dose antidepressant treatment, but 6 weeks Inhibitors,research,lifescience,medical is likely to be sufficient.30 Following response, treatment at the same dose can be maintained for 6 to 9 months, followed by tapering of the dose; if the patient, has a history of recurrent or chronic depression, then a longer duration of treatment must be considered.30 Augmentation strategies Augmentation involves adding another agent to an ongoing antidepressant treatment that, has failed. Lithium augmentation is a heptaminol commonly used strategy to treat resistant depression, with a long history of small controlled trials and anecdotal reports on benefits of lithium augmentation.31,32 Thyroid hormone augmentation of antidepressants has been reported since the late 1960s. Altshuler and colleagues summarized the early literature on triiodothyronine (T3), mainly small studies carried out many years ago, demonstrating an acceleration of time to response to antidepressants.