Mood Disorders

1. Introduction: What is a mood disorder?

A mood, in psychological terms, can be defined as a sustained affective state in which a specific pattern of feelings and emotions are sustained over a period of time. It is when a mood becomes overly extreme, persistent over an extended time frame, or unstable, that it ventures into the realm of mood disorders (Mash & Wolfe, 2013). The DSM-IV-TR defines a mood disorder as a mental state in which an individual experiences and displays symptoms of depression and/or mania (extreme elation) over an extended duration and without the influence of a definite trigger or cause, causing disruption to the sufferer’s own life as well as those around him/her (APA, 2000). Of particular concern to this review is the prevalence of depression in adolescents, which carries its own challenges in detection and classification.

1.1 Depression: a brief overview

Depression, in addition to profound sadness, causes symptoms such as anhedonia (a loss of interest in life), changes in appetite, sleep habits, anxiety, and low energy levels/fatigue. Psychomotor retardation or agitation may also afflict those suffering from depression (Nolen-Hoeksema, 2008). When symptoms like these occur together more often than can be attributed to chance or significant life events (e.g. the death of a loved one), they are referred to as a depressive syndrome (Mash & Wolfe, 2013). When such symptoms persist concurrently over a period of more than two weeks, a diagnosis of major depressive disorder (MDD) can be made. Dysthymic disorder, also listed in the DSM, is characterized by less severe symptoms that last for over a year. Depression also factors into bipolar disorder, which is characterized by alternating periods of manic and depressive symptoms (APA, 2000; Mash & Wolfe, 2013). The association of potential causes, common features and expressions, etiology, and progression of symptoms to determine the particular type of depressive disorder in an...