Escitalopram (Lexapro®) In Patients With Major Depression With Atypical Features

Based on treatment outcome, longitudinal course, biologic and physiologic data, and family histories (Rabkin et al., 1996), the American Psychiatric Association's Diagnostic and Statistical Manual, Fourth Edition (DSM-IV) (American Psychiatric Association, 1994) added atypical features as a parenthetical modifier of major depression and dysthymia. Several recent reports suggest that DSM-IV criteria for depression with atypical features identify a group distinguishable by a cluster of symptoms, age of onset and course of illness. The symptom constellation consists of depressed mood, along with hyperphagia, weight gain, increased fatigue and rejection sensitivity. Some authors have distinguished two subtypes of atypical depression. One subtype has an early onset (i.e., before age 20 years) and a chronic course (i.e., no spontaneous well-being since onset greater than 2 months) (early/chronic atypical) are no more likely to benefit from tricyclic antidepressant than from placebo (Stewart et al., 2002), but do respond to a monoamine oxidase inhibitor, and do not have increased left hemisphere perceptual processing (Stewart et al., 2003). In contrast, the other subtype reports either later onset or a less chronic course of illness (late/nonchronic atypical) respond robustly to tricyclic antidepressant (Stewart et al., 2002), and show evidence of increased left hemispheric processing (Stewart et al., 2003).

The role of the newer medications in the treatment of depressed patients with atypical features remains to be elucidated. One study compared outcome between phenelzine and fluoxetine, reporting no difference, but risk of a type II error was large (Pande et al. 1996). A second study limited to depressed patients with atypical features compared fluoxetine, imipramine, and placebo, finding both drugs effective for about half the patients and both superior to placebo, but not different from each other (McGrath et al. 2000). A 12-week study comparing moclobemide and sertraline in the treatment of outpatients with atypical depression found both drugs to produce comparable improvement (Sogaard et al, 1999). Falkai (1999) asserts the efficacy of mirtazapine for depression with atypical features without any data, and Rye et al. (1998) reported on a single case of apparently late onset atypical depression responding to bupropion. A placebo controlled study failed to show any benefit for mianserin for atypical depression (McGrath et al, 1985). Finally, an unmarketed drug, gepirone, has been demonstrated to be effective for depression with atypical features but no comparison was made with other antidepressant medications (McGrath et al., 1994).

Escitalopram has been approved for the treatment of major depression and Generalized Anxiety Disorder. However whether escitalopram improved atypical depressive symptoms has not been investigated.

Aims of Study:

The aims of this study are 1) to examine the clinical utility of escitalopram in patients with major depression with atypical features; 2) to evaluate the tolerability of escitalopram in major depression with atypical features.

Study hypothesis and objectives. This study is proposed as an open-label study to gather pilot data to examine whether escitalopram has clinical utility in the treatment of major depression with atypical features. Because of the exploratory nature of the design, no specific study hypotheses can be generated regarding efficacy of the drug. Our primary hypothesis is that the effect size of escitalopram in atypical depression will be similar to the effect size of escitalopram in major depression, its FDA approved indication.