Depression
Depression is a Mood Disorder. Mood can be defined as a pervasive and sustained emotion or
feeling tone that influences a person’s behavior and colors his or her perception of being in the
world. A variety of adjectives are used to describe mood: depressed, sad, empty, distressed,
irritable, elated, euphoric, manic, gleeful, and many others, all descriptive in nature. Mood can
be labile, fluctuating or alternating rapidly between extremes (e.g., laughing loudly and
expansively one moment, tearful and despairing the next) (Kaplan and Sadock’s Synopsis of Psychiatry,
2015).
Major Depressive Disorder or MDD
A major depressive episode must last at least 2 weeks, and typically a person with a diagnosis
of a major depressive episode also experiences at least four symptoms from a list that includes
changes in appetite and weight, changes in sleep and activity, lack of energy, feelings of guilt,
problems thinking and making decisions, and recurring thoughts of death or suicide (Kaplan and
Sadock’s Synopsis of Psychiatry, 2015).