What Are Affective (Mood) Disorders?

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Affective disorders, also known as mood disorders, are mental disorders that primarily affect a person’s emotional state. They impact the way they think, feel, and go about daily life.

There are many types of mood disorders, including major depressive disorder and bipolar disorder, among others.

Symptoms vary by condition and from person to person. It is estimated that 21.4% of adults in the United States will experience some type of mood disorder throughout their lives.

Mood disorders are not the same as normal mood fluctuations. Fluctuations in mood are a normal response to everyday occurrences and stressors, and usually do not negatively affect one’s quality of life and overall ability to function.

Mood disorders, on the other hand, can greatly affect one’s quality of life, causing issues with one’s relationships, career, and self-esteem.

Those who struggle with mood disorders may find relief through therapy, medications, and lifestyle changes.

Sad teen woman in deep sorrow sitting outside


Symptoms vary in intensity and by disorder. Two of the most common mood disorders are depression, or major depressive disorder (MDD), and bipolar disorder.


There are several different types of depression, including:

  • Major depression: Having less interest in usual activities, experiencing a depressed mood such as feeling sad or hopeless, and other symptoms for at least two weeks
  • Dysthymia (also known as persistent depressive disorder): Having chronic depressed moods accompanied by other symptoms for at least two years

Depression can have several specifiers that further characterize the mood disorder, including:

  • Seasonal affective disorder (SAD): Having depressive symptoms that recur at certain times of the year, usually during the winter months
  • Psychotic depression, or major depressive disorder with psychotic features: Experiencing severe depression plus some form of psychosis, such as having disturbing false fixed beliefs (delusions) or hearing or seeing upsetting things that others cannot hear or see (hallucinations)
  • Depression with peripartum onset or postpartum depression: Experiencing a depressive episode during pregnancy or shortly after giving birth

Symptoms of depression can include:

  • Excessive and sometimes unexplained sadness 
  • Hopelessness
  • Loss of interest in favorite activities
  • Appetite and weight changes
  • Feelings of guilt
  • Low self-esteem
  • Memory issues
  • Oversleeping or insomnia
  • Agitation
  • Suicidal ideation or attempts

Bipolar Disorder

Bipolar disorders are generally marked by shifts between depressive (extremely low mood) and manic (extremely elevated or irritable mood) episodes. There are several types of bipolar disorder. They include:

  • Bipolar I: The most severe form, with periods of full-blown mania
  • Bipolar II: Experiencing episodes of depression alternating with periods of hypomania, a form of mania that’s less severe
  • Cyclothymia: Alternating between symptoms of hypomania and depression for more than two years
  • Unspecified bipolar disorder: When symptoms are characteristic of bipolar disorder but do not meet the diagnostic criteria of the any of the other types of bipolar disorders

During mania, one may experience: 

  • Increased energy
  • Racing thoughts
  • Decreased ability and need for sleep
  • Flight of ideas
  • Grandiose thoughts 
  • Reckless behavior 

During a depressive episode as a part of a bipolar illness, one may experience symptoms similar to those of major depressive disorder, including sadness, low self-esteem, cognitive issues, and suicidal ideation.

Premenstrual Dysmorphic Disorder (PMDD)

Premenstrual dysmorphic disorder (PMDD) is a type of depressive disorder that is a severe form of premenstrual syndrome (PMS). It involves a combination of symptoms that people can experience about a week or two before their period.

Symptoms of PMDD include:

  • Severe mood swings
  • Anger and irritability
  • Increased appetite
  • Depression
  • Insomnia or sleeping more
  • Feeling a loss of control


Mood disorders can be caused by a combination of factors, including chemical imbalances in the brain, genetics, and stressful life events.

Chemical Imbalances

Neurons are the building blocks of the brain and nervous system. Neurons communicate with other neurons, glands, and muscles through the release of substances known as neurotransmitters. These chemicals are involved in everything, from our basic biological functions, such as breathing, to our fight-or-flight response.

Neurotransmitters are also involved in the regulation of moods and emotions. A number of neurotransmitters are involved in mood disorders. One that plays an integral role in the development or susceptibility to depression is serotonin. Lower levels of serotonin may contribute to depression.

Other neurotransmitters commonly associated with mood disorders include dopamine and norepinephrine.

Brain Structure

Brain structure is also believed to play a role in depression. Researchers have found one area in the brain, the hippocampus, is smaller in depressed patients. They believe the reason for this may be because extended, ongoing exposure to stress hormones hindered the growth of nerve cells within that brain region.

Other brain structures potentially involved in mood disorders include the amygdala and thalamus.


Genetics are a significant factor involved in the susceptibility of mood disorders, and mood disorders are known to run in families.

Life Events and Changes

Stressful life events and changes, including starting a new job, moving, and other transitional periods, can also spark a mood disorder such as depression.


There is not a single test for determining if one has a mood disorder. Rather, a healthcare provider will conduct a psychiatric evaluation and take note of all the symptoms someone is experiencing to determine the correct diagnosis.

Healthcare providers use the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) to diagnose mental disorders, including mood disorders. This guide contains diagnostic criteria for each mental disorder.


In order to be diagnosed with depression, you must experience symptoms for at least two weeks. However, this timeline will differ based on the specific type of depression you are experiencing. For example:

  • Dysthymia: Symptoms must be present for two years or more.
  • Major depressive disorder with a peripartum onset: Symptoms must be present during pregnancy or within four weeks of giving birth.
  • Seasonal affective disorder (SAD): Symptoms must be recurrent during a particular time of year, usually the winter months.

Depression appears differently in every person, and no two cases are the same. As such, not every symptom will be experienced by each person diagnosed with depression. However, several persistent symptoms must be present within the timeframe specified for the given depression type to qualify.

Bipolar Disorder

Healthcare providers diagnose bipolar disorder based on symptoms, experiences, and histories. One must experience at least one episode of mania or hypomania to be diagnosed with bipolar I disorder, as well as a depressive episode that lasts at least two weeks to be diagnosed with bipolar II disorder.


Options for treating affective disorders include medications and therapy. Lifestyle changes, such as increasing exercise, eating a healthy diet, and reducing stress, may also help. Because of the complexity of factors involved in mood disorders, it is vital to approach treatment from different angles.

Usually, a combination of medication and therapy is recommended. Keep in mind, however, that treatment plans will vary based on individual needs. It’s best to talk to your healthcare provider for your own best course of action.


Various psychiatric medications are available for the treatment of various mood disorders. Each of these interacts with neurotransmitter levels in the brain to help treat any potential imbalances.

Some common medications prescribed to help treat mood disorders include:

  • Selective serotonin reuptake inhibitors (SSRIs)
  • Serotonin–norepinephrine reuptake inhibitors (SNRIs)
  • Antipsychotics
  • Mood stabilizers
  • N-Methyl-D-Aspartate NMDA receptor antagonists


Psychotherapy is another option for treatment. However, therapy is not one-size-fits-all and there are many options.

Common therapies used for the treatment of mood disorders include:

  • Cognitive behavioral therapy (CBT): CBT focuses on reworking negative, disruptive thought patterns. It is used in treating both depression and bipolar disorder.
  • Dialectical behavioral therapy (DBT): DBT was originally created for the treatment of borderline personality disorder (BPD), but has since shown to be helpful in managing moods in cases of depression and bipolar disorder as well.


Lifestyle can contribute to better management of mood disorders. Some changes that can help include:

  • Engage in regular exercise: Exercise can be beneficial in the treatment of mood disorders.
  • Build healthy relationships: The people you surround yourself with have a huge impact on your well-being. Maintaining strong, healthy, and nourishing relationships with your loved ones can vastly improve your mental health.
  • Focus on sleep: Practicing proper sleep hygiene is imperative to managing depression. There are a number of known best practices for getting better sleep.
  • Avoid alcohol: Excessive and persistent drinking increases your odds of developing depression. Drinking in moderation or avoiding it is recommended for those who struggle with a mood disorder.


Living with a mood disorder is no easy feat. Affective disorders can touch every area of life, from relationships to careers to self-esteem to physical health. However, it is possible to live well despite the difficulties that come with these types of mental disorders.

Focusing on sleep hygiene, getting support from friends and family, getting regular exercise, eating healthy, and staying away from substances can vastly improve your quality of life if you are living with a mood disorder.

Joining a support group can help you feel less alone in your struggles as well. Organizations that can be helpful in finding support include the National Alliance on Mental Illness (NAMI) and Substance Abuse and Mental Health Services Administration.

When to Seek Help

If you or a loved one is struggling with depression, contact the Substance Abuse and Mental Health Services Administration (SAMHSA) National Helpline at 1-800-662-4357 for information on support and treatment facilities in your area.

For more mental health resources, see our National Helpline Database.

A Word From Verywell

It is absolutely vital to speak up when you’re struggling and seek professional guidance for assistance in managing your symptoms if you have a mood disorder. Since mood disorders look different for every individual, your treatment plan should be tailored to your specific needs and situation.

While mood disorders can be episodic, they can also present a lifelong vulnerability. Treatment should be focused on the management of symptoms to minimize their impact on your daily life.

Most importantly, keep in mind that a mood disorder in no way defines you or dictates how full of a life you can lead. Many people with mood disorders lead happy and fulfilling lives by managing their symptoms through a combination of therapy, medication, and self-care.

12 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Molly Burford
Molly Burford is a mental health advocate and wellness book author with almost 10 years of experience in digital media.