“Mood disorders” is an umbrella term that refers to different psychiatric conditions that cause changes to a person’s emotional state, leading to long periods of joy, elation, mania, sadness, and/or depression. Psychiatric conditions that fall under this category include depressive disorders and bipolar spectrum disorders.

People with mood disorders experience a decreased quality of life; if they have depressive episodes, they may feel irritable, worthless, or uninterested in things they normally care about. They may also have suicidal thoughts and/or behaviors. If they experience episodes of mania, they may feel overly energetic or on a natural high, with racing thoughts and words that pour out more quickly than usual.

It’s common for mood disorders to arise during adolescence, but people may be affected at any age, even into adulthood. About 15% of children and adolescents are affected by mood disorders. Females are more likely to experience mood disorders than males. People with chronic medical conditions are also more likely to experience mood disorders, particularly depressive disorders.

A variety of treatments are available to help stabilize mood disorders so that patients can lead more balanced lives.

Mood disorders are psychiatric conditions that affect a person’s emotional state. The symptoms may be mild, moderate, or severe. They may decrease a person’s quality of life and, in some cases, make it difficult to function normally.

Mood disorders fall into two categories: depressive disorders and bipolar spectrum disorders.

Depressive disorders include:

• Major depressive disorder (also known as clinical depression), when a person experiences persistent sadness, a loss of interest in favorite activities, changes to eating and/or sleeping habits, feelings of worthlessness or hopelessness, trouble concentrating, and/or related symptoms for at least two weeks
• Persistent depressive disorder (also known as dysthymia), when a person has mild to moderate symptoms of depression on more days than not for two years (or one year for children or adolescents); symptoms aren’t as intense as those associated with major depressive disorder
• Seasonal affective disorder (SAD), when a person experiences symptoms of major depressive disorder during colder months of the year, when the days are shorter and darker
• Disruptive mood dysregulation disorder (DMDD), when a child or adolescent is more angry and irritable than expected, based on their circumstances
• Premenstrual dysphoric disorder (PMDD), when depressive symptoms arise the week before a woman’s menstrual period and fade away with the onset of menstruation
• Postpartum depression, when symptoms of depression arise in a new mother during the four weeks immediately after childbirth

Bipolar spectrum disorders include, in addition to depressive episodes, one or more episodes of mania or hypomania.

• Mania, when a person experiences feelings of elation for at least a week, along with high energy levels, little desire for sleep, irritability, distractibility, and poor lifestyle choices, including making risky decisions
• Hypomania, which is a less intense version of mania, with milder symptoms that may last at least four days

Depending on how manic and hypomanic episodes alternate with depressive episodes, several types of bipolar disorders have been described:

• Bipolar disorder I, which is marked by at least one episode of mania and some symptoms of major depressive disorder
• Bipolar disorder II, which is characterized by episodes of major depressive disorder and at least one episode of hypomania
• Cyclothymia, which is similar to bipolar disorder, with milder symptoms that lasts about two years

All people experience changes in their emotions, including highs and lows. Feeling sadness, grief, joy, or elation is not the same as having a mood disorder. However, when a person experiences sadness for two weeks or longer, along with significant changes to eating, sleeping, or other lifestyle habits that make it difficult to function, or if they feel elated for an extended period, eager to carry out risky, impulsive ideas—and/or a combination of the two—that is considered a mood disorder.

Doctors don’t know the exact cause of mood disorders. They may be caused by brain changes, a chemical imbalance in the brain, genetic factors, certain medical conditions, use of psychoactive substances or other factors.

Sometimes, people with mood disorders have brain regions that are larger than they should be, including the amygdala, which helps to control a person’s emotions and feelings, and ventricles, the spaces within the brain that hold cerebrospinal fluid.

People may also experience mood disorders if brain chemicals, including serotonin, norepinephrine, and dopamine, are out of balance.

When mood disorders are caused by use of psychoactive substances (e.g., cocaine), symptoms typically resolve when use of the particular substance is stopped.

These medical conditions are linked with mood disorders:

• Brain tumors
• Encephalitis
• Syphilis
• Multiple sclerosis
• Heart disease
• Chronic kidney disease
• Thyroid disease (hypothyroidism or hyperthyroidism)
• AIDS
• Influenza (the flu)
• Cancer
• Q fever, which spreads from animals to people
• Metabolic changes linked to hemodialysis
• Certain genetic diseases such as Wilson disease

Because the term encompasses many different conditions, mood disorders can cause a wide range of symptoms.

Symptoms of depressive disorders include persistent feelings of:

• Sadness or emptiness
• Anxiety
• Hopelessness
• Helplessness
• Worthlessness
• Guilt
• Pessimism
• Irritability or frustration
• Negativity
• Anger
• Restlessness

People with depressive disorders may also experience:

• Loss of interest in people and activities that they previously enjoyed
• Low energy levels or fatigue
• Moving or speaking more slowly than usual
• Trouble thinking, concentrating, or recalling information
• Decrease in libido
• Changes in sleeping habits (getting significantly more or less sleep)
• Changes in eating habits (consuming significantly more or less food)
• Unintended weight gain or loss
• Headaches, stomachaches, or body aches that aren’t caused by the usual triggers and don’t respond to the standard treatments
• Withdrawing from loved ones
• Difficulty keeping up with responsibilities at home, work, or school
• Becoming more impulsive
• Using mood-altering drugs, including alcohol, more than usual
• Persistent thoughts about death
• Suicidal thoughts and behaviors

Symptoms of bipolar spectrum disorders include feelings of:

• Elation or joy
• Being on a natural high
• Higher levels of self-esteem than usual
• Invincibility
• Impulsivity
• Irritability
• Sadness
• Anxiety
• Excessive emotional sensitivity
• Hopelessness
• Helplessness
• Worthlessness
• Pessimism
• Restlessness

People with bipolar disorders may also experience a range of emotions, depending on whether they are experiencing a depressive or manic episode.

During a depressive episode, someone may experience:

• Loss of interest in people and activities
• Low energy levels
• Slowed speech
• Difficulty concentrating or remembering things
• Difficulty sleeping or sleeping too much
• Decreased libido
• Increased use of mood-altering drugs, including alcohol
• An inability to keep up with responsibilities at home, work, or school
• Suicidal thoughts or behaviors

During a manic episode, someone may experience:

• Becoming much more interested in people and activities, especially pleasurable ones (eating and sex, for example)
• Having extremely high energy levels, with a sense that they can accomplish many things in short time frames
• Speaking very quickly, changing topics often
• Having racing thoughts on a variety of topics
• Feeling a decreased need for sleep
• Increased libido
• Disregarding responsibilities at home, work, or school
• Increased use of drugs and/or alcohol

People may be at greater risk of mood disorders if they have:

• A personal or family history of mood disorders
• A personal history of traumatic or stressful events, including child sexual abuse
• Abnormalities in brain structure or function

Doctors who suspect a mood disorder will take a patient’s medical history and offer diagnostic tests to rule out other conditions that cause similar symptoms before referring the patient to a mental health professional for a diagnosis.

If you suspect that you have a mood disorder, share details about your symptoms with a doctor. Let them know how long you have felt different whether depression has changed how you interact with people, and whether your symptoms interfere with your ability to function normally or honor your responsibilities. Doctors may offer you questionnaires to assess for symptoms of mania or depression. Many people with bipolar spectrum disorders who experience mania-type symptoms may not recognize the behaviors as problematic, so they may not mention these to a doctor. Still, they are worthwhile to include (if you recognize them) when you share your medical history.

You should also share details about a personal or family history of mood disorders. If you’ve been treated for a mood disorder, tell the doctor what medication you took. Also tell your doctor about any medication or recreational drugs you’ve taken recently. Cocaine, amphetamines, steroids, the chemotherapy drug procarbazine, and other medications may cause symptoms that mimic mood disorders.

There are no diagnostic tests for mood disorders. Doctors may offer tests to look for conditions that may cause similar symptoms, including blood tests to look at thyroid hormone levels or sleep studies to look for insomnia or sleep abnormalities. The tests that doctors offer may vary based on your symptoms. Doctors may also order a magnetic resonance imaging (MRI) scan of the brain to look for structural or functional abnormalities. If, after the medical and physical exam, the doctor suspects a mood disorder, they will refer you to a mental health professional for a diagnosis.

Treatments for mood disorders help to improve patients’ quality of life. When suicidal thoughts are present, treatment helps to reduce the risk of death. (In some patients, however, taking antidepressants increases the risk of suicidal thoughts.) A variety of treatment options are available, depending on the diagnosis and the patient’s response to treatment.

Treatments for depressive disorders include:

• Selective serotonin reuptake inhibitors (SSRIs), a class of antidepressants that increases levels of serotonin in the brain
• Serotonin-norepinephrine reuptake inhibitors, a class of antidepressants that increases levels of serotonin and norepinephrine in the brain
• Tricyclic antidepressants, which prevent serotonin and norepinephrine from being reabsorbed in the brain
• Atypical antidepressants, which have positive effects on brain chemistry
• Monoamine oxidase inhibitors, a class of antidepressants that removes norepinephrine, serotonin, and dopamine from the brain so they can be used elsewhere to combat symptoms of depression
• Serotonin modulators, a class of antidepressants that alters the way the brain processes serotonin
• Esketamine, which can be used for treatment-resistant depression.
• Cognitive behavioral therapy (CBT), A type of psychotherapy that helps to improve depressive disorders by helping patients reframe their thoughts in a more positive way
• Phototherapy, which exposes a patient to bright light at close range as a treatment for seasonal affective disorder
• Vagus nerve stimulation, in which a device implanted in the chest stimulates the vagus nerve (which runs through the chest to the brain) to alter brain activity and improve symptoms of depression; this treatment may help when other treatments aren’t effective

Treatments for bipolar spectrum disorders include:

• Mood stabilizers, like lithium and valproic acid, which alter brain chemistry to reduce symptoms
• Certain atypical antipsychotics, including risperidone, which may help to reduce severe symptoms when combined with a mood stabilizer
• Anticonvulsants, including carbamazepine or benzodiazepines, which may improve brain chemistry, reducing symptoms
• Thyroid hormone, which may affect brain chemistry to improve mood

Lifestyle changes that may improve symptoms of any mood disorder include:

• Eating a healthy diet rich in whole foods, including fish and other foods high in omega-3 fatty acids, which have positive effects on serotonin and dopamine levels in the brain
• Getting physical activity regularly, which helps to boost mood
• Sleeping enough each night
• Quitting smoking

Treatments for mood disorders can be effective, but about one-half of people with them will experience recurrences once their symptoms resolve. It isn’t possible to predict which patients will have recurrences. Some patients also develop anxiety disorders or psychosis after having a mood disorder.

When diagnosis and treatment are delayed, patients tend to have worse outcomes. People diagnosed late with bipolar disorder—due to a misdiagnosis or not seeking a diagnosis earlier—may develop a substance use disorder.

People with mood disorders are more likely to have a poorer quality of life than those who do not have them. They are more likely to experience suicidal thoughts/plans or have anxiety, a substance use disorder, or other health problems.

This article was reviewed by Yale Medicine psychiatrist Paula Zimbrean, MD.