Mood disorder

A mood disorder, sometimes called an affective disorder, is a category of mental and behavioral conditions where the core issue is a disruption in a person's mood. These conditions are classified in the Diagnostic and Statistical Manual of Mental Disorders (DSM) and the International Classification of Diseases (ICD). Mood disorders are grouped into seven types, which include: an abnormally elevated mood (like mania or hypomania); a depressed mood (the most well-known form being major depressive disorder, also called clinical depression, unipolar depression, or major depression); moods that cycle between mania and depression (known as bipolar disorder, formerly manic depression); and several subtypes of depressive disorders or psychiatric syndromes with less severe symptoms, such as dysthymic disorder (similar to major depressive disorder but longer-lasting and often milder) and cyclothymic disorder (similar to but milder than bipolar disorder). It is possible for a person to have more than one mood disorder at the same time, such as both bipolar disorder and a depressive disorder. Mood disorders can also be caused by substance use or occur as a response to a medical condition.

The English psychiatrist Henry Maudsley first proposed the overarching category of "affective disorder." This term was later replaced by "mood disorder," because the latter refers to the underlying or long-term emotional state, while the former described the external expression observed by others.

**Depressive disorders** include major depressive disorder (MDD), commonly called major depression, unipolar depression, or clinical depression. A person with MDD experiences one or more major depressive episodes. After a single episode, the diagnosis is Major Depressive Disorder (single episode); symptoms must be present nearly all day for at least two weeks. After more than one episode, the diagnosis becomes Major Depressive Disorder (Recurrent). Depression without periods of mania is sometimes called unipolar depression because the mood stays at the bottom "pole" and does not rise to the higher, manic "pole" as in bipolar disorder.

People experiencing a major depressive episode or major depressive disorder have an increased risk of suicide. Seeking help and treatment from a health professional dramatically lowers this risk. Studies show that asking a depressed friend or family member if they have thought about suicide is an effective way to identify those at risk, and it does not "plant" the idea or increase the risk of suicide. Epidemiological studies in Europe suggest that about 8.5 percent of the world's population currently has a depressive disorder. No age group is exempt; studies have found depression in infants as young as six months old who were separated from their mothers. However, cultural differences may affect the prevalence of MDD, as cultural influences can "challenge the definition and diagnosis of psychiatric disorders," a point seen in a study by Parker et al. on MDD in Chinese individuals. Depressive disorder is a common mental disorder involving a depressed mood or loss of pleasure or interest in activities for long periods. It is different from regular mood changes and everyday feelings, and it can affect all aspects of life. Anyone can develop depression, but people who have experienced abuse, severe losses, or other stressful events are more likely to do so.

Depressive disorder is common in primary care and general hospital settings but is often undetected. Unrecognized depressive disorder can slow recovery and worsen the prognosis for physical illness, so it is important for all doctors to recognize the condition, treat less severe cases, and identify those needing specialist care.

Diagnosticians recognize several subtypes or course specifiers:

- **Atypical depression (AD)** is marked by mood reactivity (paradoxical anhedonia) and positivity, significant weight gain or increased appetite ("comfort eating"), excessive sleep (hypersomnia), a sensation of heaviness in the limbs (leaden paralysis), and significant social impairment due to hypersensitivity to perceived interpersonal rejection. Difficulties in measuring this subtype have raised questions about its validity and prevalence. - **Melancholic depression** is characterized by a loss of pleasure (anhedonia) in most or all activities, a failure to react to pleasurable stimuli, a depressed mood more pronounced than grief or loss, worsening of symptoms in the morning, early-morning waking, psychomotor retardation, excessive weight loss (not to be confused with anorexia nervosa), or excessive guilt. - **Psychotic major depression (PMD)**, or psychotic depression, refers to a major depressive episode, especially of a melancholic nature, where the patient experiences psychotic symptoms like delusions or, less often, hallucinations. These symptoms are usually mood-congruent (their content matches depressive themes). - **Catatonic depression** is a rare and severe form of major depression involving disturbances in motor behavior and other symptoms. The person may be mute, nearly stuporous, immobile, or exhibit purposeless or bizarre movements. Catatonic symptoms can also occur in schizophrenia, a manic episode, or due to neuroleptic malignant syndrome. - **Postpartum depression (PPD)** is listed as a course specifier in DSM-IV-TR. It refers to the intense, sustained, and sometimes disabling depression experienced by women after childbirth. PPD affects 10–15% of women, typically begins within three months of labor, and can last up to three months. It is quite common for women to experience.