As a result of the variation of MDD between individuals, organizations such as the World Health Organization (WHO) and the Diagnosis and Statistical Manual of Mental Disorders, fifth edition (DSM-V) have developed diagnostic criteria. The WHO describes a Major Depressive episode as a period of time lasting at least 2 weeks where the individual experiences a depressed mood and loss of interest/pleasure along with at least 4 additional symptoms across different changes in functioning. Examples of these functions include, but are not limited to, sleeping, eating, energy, concentration, self-image, and weight.1 The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM – V) characterizes Major Depressive Disorder in a similar, …show more content…
The DSM – V goes further as to categorize the severity of the individual episode as shown in Figure 1.2.6 By and large the methods available for the diagnosis of MDD are limited to self-reports and behavioral observation.5 Research conducted by the University of Utah School of Medicine concluded that one of the major issues with this method is that the symptoms of MDD can mimic that of other disorders that co-exist leading to many confounds effecting a proper diagnosis. In many instances, medical professionals rely on a trial and error approach where a patient’s response (or lack thereof) to a cocktail of antidepressant medications is a key component of their final diagnosis. These factors combined lead to a high rate of misdiagnosis, in addition to ineffective treatment plans. In order to mitigate the risk of misdiagnosis, research has shifted away from these behavioral methods and moved towards examining both genomic and proteomic methodology to identify biomarkers. Biomarkers are defined as any biomolecule or panel of biomolecules that can aid in the diagnosis of a disease or prediction of biology. The most commonly studied methods use polymerase chain reaction and mass spectroscopy