Definitions of Depressive Disorders:
From the DSM-5:
Depressive disorder includes disruptive mood dysregulation disorder, major depressive disorder (including major depressive episode), persistent depressive disorder (dysthymia), premenstrual dysphoric disorder, substance/medication-induced depressive disorder, depressive disorder due to another medical condition, other specified depressive disorder, and unspecified depressive disorder.
From the American Psychological Association’s Glossary of Psychological Terms:
Major depressive disorder: A mood disorder characterized by intense feelings of depression over an extended time, without the manic high phase of bipolar depression.
From the National Institute of Mental Health:
Depression (major depressive disorder or clinical depression) is a common but serious mood disorder. It causes severe symptoms that affect how you feel, think, and handle daily activities, such as sleeping, eating, or working. To be diagnosed with depression, the symptoms must be present for at least two weeks.
Types of Depressive Disorders (from the DSM-5):
Disruptive Mood Dysregulation Disorder: ‘The core feature of disruptive mood dysregulation disorder is chronic, severe persistent irritability. This severe irritability has two prominent clinical manifestations, the first of which is frequent temper outbursts… The second manifestation of sever irritability consists of chronic, persistent irritable or angry mood that is present between severe temper outbursts.’
Major Depressive Disorder: ’The criterion symptoms for major depressive disorder must be present nearly every day to be considered present, with the exception of weight change and suicidal ideation. Depressive mood must be present for most of the day, in addition to being present nearly every day.’
Persistent Depressive Disorder (Dysthymia): ’The essential feature of persistent depressive disorder (dysthymia) is a depressed mood that occurs for most of the day, for more days than not, for at least 2 years, or at least 1 year for children and adolescents.’
Premenstrual Dysphoric Disorder: ’The essential feature of premenstrual dysphoric disorder are the expression of mood lability, irritability, dysphoria, and anxiety symptoms that occur repeatedly during the premenstrual phase of the cycle and remit around the onset of menes or shortly thereafter.’
Substance/Medication-Induced Depressive Disorder: ‘The diagnostic features of substance/medication-induced depressive disorder include the symptoms of a depressive disorder, such as major depressive disorder, however, the depressive symptoms are associated with the ingestion, injection, or inhalation of a substance (e.g. drug of abuse, toxin, psychotropic medication, other medication), and the depressive symptoms persist beyond the expected length of psychological effects, intoxication, or withdrawal period.’
Depressive Disorder Due to Another Medical Condition: ‘The essential feature of depressive disorder due to another medical condition is a prominent and persistent period of depressed mood or markedly diminished interest or pleasure in all, or almost all, activities that predominates in the clinical picture and that is thought to be related to the direct physiological effects of another medical condition.’
Other Specified Depressive Disorder and Unspecified Depressive Disorder: ‘This category applies to presentations in which symptoms characteristic of a depressive disorder that cause clinically significant distress of impairment in social, occupational, or other important areas of functioning predominate but do not meet the full criteria for any of the disorders in the depressive disorders diagnostic class.’
American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Depressive Disorders (155-184). Arlington, VA, American Psychiatric Association, 2013.
Gerrig, R. J., & Zimbardo, P. G. (2002). In Glossary of Psychological Terms. Retrieved from http://www.apa.org/research/action/glossary.aspx?tab=13
Depression (2016, May). In National Institute of Mental Health. Retrieved from https://www.nimh.nih.gov/health/topics/depression/index.shtml
Disclaimer: Due to the nature of this post, this information is meant to be informative and not a diagnosis for depression. If you believe you or someone you know have depression, please seek out a doctor or professional for a proper diagnosis.