Overview

Abstract

Depressive disorders are among the most prevalent and debilitating mental conditions, with major depressive disorder (MDD) as the most representative diagnostic category. The main symptoms of MDD refer to persistent negative mood and/or loss of interest and pleasure for previously enjoyed activities, as well as additional features, like loss of appetite, sleep disturbance, low self-esteem, suicidal ideation or risk, fatigue, indecisiveness, difficulty concentrating, etc. One-year prevalence rates of MDD vary between 3% and 10% in the USA (Kessler & Bromet, 2013) and 5% in Western Europe (Olesen et al., 2012), with lifetime prevalence rates higher than 15% (Kessler et al., 2003). According to the World Health Organization (WHO), MDD is estimated to become the leading cause of burden and disease by 2030 (Mathers & Loncar, 2006), and is associated with huge personal and societal costs, both directly, and through comorbidities (Greenberg, Fournier, Sisitsky, Pike, & Kessler, 2015). In this sense, in the United States, depression-related costs have increased by 21.5% between 2000 and 2015, most expenditure due to workplace costs (50%) and direct costs (45%) (Greenberg et al., 2015). The most important associated risk is suicide, with half the number of suicides being related to depressive and mood disorders, and depressed individuals having a 20-fold greater risk of suicide (Lépine & Briley, 2011). Also, MDD is highly comorbid with other mental disorders, such as anxiety disorders, substance use, or eating disorders. For instance, about 50% of depressed people in community and primary care settings also suffer from an anxiety disorder, thus making pure depression rather the exception, and not the rule (Kessler et al., 1996). In relation to substance abuse, data have shown that almost a third of MDD patients also have substance use disorders, this comorbidity leading to higher suicide risk, and greater functional and social impairment (David, Szentagotai, Lupu, & Cosman, 2008). Importantly, chronic depression is also comorbid with physical medical conditions, such as heart disease and diabetes, leading to increased healthcare costs, increased medical symptom burden, functional impairment, lower treatment adherence, and a higher risk of morbidity and mortality (Katon, 2011). In this context of depression continuing to be a major problem for individuals and society, investigating effective treatments and delivering evidence-based practices is paramount. This book aims to present detailed, accessible protocols for adult depression, as well as published data pointing to its efficacy.