What are Mood Disorders?

Broadly speaking, a mood disorder is a mental health condition characterized by a significant, prolonged emotional disturbance that affects an individual’s ability to function in their daily life. The emotional disturbance can be low, sad, and depressive, or high-energy, unpredictable, and manic. The type of disturbance depends on the disorder, and some mood disorders include both depressive and manic episodes.

The average age of onset for mood disorders is the early-to-late 20s. However, children and adolescents can develop mood disorders as well. The initial presentation and symptoms of mood disorders in children and adolescents may vary from those seen in adults, which, combined with the fact that children are not always capable of clearly articulating their emotions, makes diagnosing mood disorders in children and adolescents challenging.

How Common are Mood Disorders?

The most common mood disorders are major depressive disorder, bipolar disorder I, and seasonal affective disorder. Data from Harvard University from 2007 shows the following prevalence rates for people diagnosed with any mood disorder:

Adults (age 18 +)

  • 7% (31.5 million)
    • 6% for females
    • 7% for males
  • Of those adults:
    • 45% had severe impairment
    • 40% had moderate impairment
    • 15% had mild impairment

Adolescents (age 12-17)

  • 3 % (3.5 million)
    • 3% for females
    • 5% for males
  • 2% (2.8 million) had severe impairment

Additional data on mood disorder prevalence from the 2019 National Survey on Drug Use and Health (2019 NSDUH) shows an increase in mood disorders among adolescents:

  • 7% (3.8 million) met criteria for depression
  • 1% (2.7 million) met criteria for depression with severe impairment

The data shows two things parents should know. First, the prevalence of mood disorders – particularly depression – is increasing among adolescents in the U.S. Second, mood disorders are more common among adolescent females than adolescent males – and this pattern continues into adulthood.

What are the Different Types of Mood Disorders?

Prior to 2013, the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) classified depressive disorders and bipolar-type disorders as mood disorders. In 2013, the updated DSM-V created separate categories of bipolar disorders and mood disorders.

Here are the new categories:

Mood Disorders:

Disruptive mood dysregulation disorder (DMDD). This disorder is characterized by persistent anger, irritability, and frequent extreme tantrums that seem unprovoked.

Click here to learn more about DMDD symptoms, treatment, and support.

Major depressive disorder (MDD). This is the disorder most people think of when they hear the term depression. People with MDD experience episodes of extreme sadness and hopelessness for periods of two weeks or more, often accompanied by various other physical and cognitive symptoms.

Click here to learn more about MDD symptoms, treatment, and support.

Persistent depressive disorder (PDD). This is a subtype of MDE. People with PDD experience mild-to-moderate symptoms of depression for two years or longer. PDD was previously called dysthymia or dysthymic disorder.

Premenstrual dysphoric disorder (PMDD). Mood swings, irritability, anxiety, and other mood-related symptoms that appear the week before menstruation and resolve after the onset of menstruation characterize the disorder known as PMDD.

Substance/Medication induced depressive disorder. This disorder has the same symptoms as MDE and PDD, but they appear immediately or shortly after an individual begins taking a drug or medication. Symptoms of this disorder may also appear during the withdrawal period after an individual stops taking a drug or medication.

Depressive disorder due to another medical condition. This is a type of depression caused by medical conditions that have a significant impact on general health or from long-term medical conditions that cause chronic pain. Evidence shows that people with the following medical conditions have an increased likelihood of developing this type of depression: cancer, autoimmune disorders, brain disorders, metabolic conditions, diabetes, stroke, and arthritis, among others.

Bipolar Disorders:

Bipolar I disorder (BD-I). People diagnosed with BD-I experience periods of mania, depression, or mixed episodes that last for a week or more, affect sleep or daily functioning, or occur immediately before or after a depressive episode of two weeks or longer.

Bipolar II disorder (BD-II). People diagnosed with BD-II experience periods of mania, hypomania depression, or mixed episodes that are less intense than those experienced by people with bipolar I. These milder manic episodes are called hypomanic or hypomania.

Cyclothymic disorder (cyclothymia). People diagnosed with cyclothymic disorder experience numerous periods of depressive symptoms and hypomanic symptoms, but do not experience the full hypomanic or major depressive episodes common to bipolar I or bipolar II.

Click here to learn more about bipolar disorder symptoms, treatment, and support.