Despite an increasing variety of therapeutic options available for
residual symptoms following an incomplete symptom remission
from MDD, the majority of patients will remain symptomatic
(Trivedi et al., 2008; Philip et al, 2010). As reviewed, to date only
a few pharmacological agents have met criteria for statistically
significant clinical improvement and are approved in treatmentresistant MDD. The psychotropic medications currently approved
in the USA include aripiprazole, a combination of olanzapine/
fluoxetine, and quetiapine XR (Philip et al, 2010). Given the
increasing universal burden of MDD and the clinical reality that
only a third of patients achieve a state of symptom remission
following an initial trial of antidepressant monotherapy, there is
need for more collaboration in fundamental research to better
establish first-line adjunctive treatments, that may be effective
to improve clinical outcomes in the management of treatmentresistant MDD. There is great personal psychological liability and
demoralization associated with a failure to respond to a trial of
an antidepressant. As well, the negative impact of untreated
residual symptoms of MDD includes fatigue, cognitive dulling,