What are Mood Disorders?
Mood disorders are a category of illnesses that describe a severe change in mood. Illness under mood disorders includes major depressive disorder, bipolar disorder (mania – euphoric, hyperactive, overinflated ego, unrealistic optimism), persistent depressive disorder (long-lasting low-grade depression), cyclothymia (a mild form of bipolar disorder), and SAD (seasonal affective disorder). (MHA)
Major Depressive Disorder
Depression (major depressive disorder) is a common and serious medical illness that negatively affects how you feel, the way you think, and how you act. Fortunately, it is also treatable. Depression causes feelings of sadness and/or a loss of interest in activities you once enjoyed. It can lead to a variety of emotional and physical problems and can decrease your ability to function at work and home (American Psychiatric Association).
In 2021, an estimated 21.0 million adults in the United States had at least one major depressive episode. This number represented 8.3% of all U.S. adults (NIMH).
What causes depression?
There are a variety of causes of depression, including genetic, environmental, psychological, and biochemical factors.
A person has an increased risk of depression if their family has a history of depression, they have experienced trauma, significant life changes, stress, or certain physical illnesses (such as diabetes, cancer, or Parkinson’s), or as a side effect to certain medications (SAMHSA).
Signs and symptoms of depression
If you have been experiencing some of the following signs and symptoms most of the day, nearly every day, for at least two weeks, you may be experiencing depression:
- Persistent sad, anxious, or “empty” mood
- Feelings of hopelessness or pessimism
- Feelings of irritability, frustration, or restlessness
- Feelings of guilt, worthlessness, or helplessness
- Loss of interest or pleasure in hobbies and activities
- Decreased energy, fatigue, or feeling slowed down
- Difficulty concentrating, remembering, or making decisions
- Difficulty sleeping, waking early in the morning, or oversleeping
- Changes in appetite or unplanned weight changes
- Physical aches or pains, headaches, cramps, or digestive problems that do not have a clear physical cause and do not go away with treatment
- Thoughts of death or suicide or suicide attempts
Not everyone who is depressed experiences every one of these symptoms. Some people experience only a few symptoms, while others experience many symptoms. Symptoms associated with depression interfere with day-to-day functioning and cause significant distress for the person experiencing them.
Depression can also involve other changes in mood or behavior that include:
- Increased anger or irritability
- Feeling restless or on edge
- Becoming withdrawn, negative, or detached
- Increased engagement in high-risk activities
- Greater impulsivity
- Increased use of alcohol or drugs
- Isolating from family and friends
- Inability to meet the responsibilities of work and family or ignoring other important roles
Seasonal Affective Disorder
Many people go through short periods of time where they feel sad or not like their usual selves. Sometimes, these mood changes begin and end when the seasons change. People may start to feel “down” when the days get shorter in the fall and winter (also called “winter blues”) and begin to feel better in the spring, with longer daylight hours.
Sometimes, these mood changes are more severe and can affect how a person feels, thinks, and handles daily activities. If you have noticed significant changes in your mood and behavior whenever the seasons change, you may be suffering from seasonal affective disorder (SAD), a type of depression.
In most cases, SAD symptoms start in the late fall or early winter and go away during the spring and summer; this is known as winter-pattern SAD or winter depression. Some people may experience depressive episodes during the spring and summer months; this is called summer-pattern SAD or summer depression and is less common (NIMH).
About 5 percent of adults in the U.S. experience SAD, and it typically lasts about 40 percent of the year (American Psychiatric Association).
What causes Seasonal Affective Disorder?
Scientists do not fully understand what causes SAD. Research indicates that people with SAD may have reduced activity of the brain chemical (neurotransmitter) serotonin, which helps regulate mood. Research also suggests that sunlight controls the levels of molecules that help maintain normal serotonin levels, but in people with SAD, this regulation does not function properly, resulting in decreased serotonin levels in the winter.
Other findings suggest that people with SAD produce too much melatonin—a hormone that is central for maintaining the normal sleep-wake cycle. Overproduction of melatonin can increase sleepiness.
Both serotonin and melatonin help maintain the body’s daily rhythm, which is tied to the seasonal night-day cycle. In people with SAD, the changes in serotonin and melatonin levels disrupt the normal daily rhythms. As a result, they can no longer adjust to the seasonal changes in day length, leading to sleep, mood, and behavior changes.
Vitamin D deficiency may exacerbate these problems because vitamin D is believed to promote serotonin activity. In addition to vitamin D consumed with diet, the body produces vitamin D when exposed to sunlight on the skin. With less daylight in the winter, people with SAD may have lower vitamin D levels, which may further hinder serotonin activity.
Negative thoughts and feelings about the winter and its associated limitations and stresses are common among people with SAD (as well as others). It is unclear whether these are “causes” or “effects” of the mood disorder, but they can be a valuable focus of treatment (NIMH).
Signs and Symptoms
SAD is not considered a separate disorder but is a type of depression characterized by its recurrent seasonal pattern, with symptoms lasting about 4 to 5 months per year. Therefore, the signs and symptoms of SAD include those associated with major depression and some specific symptoms that differ for winter-pattern and summer-pattern SAD. Not every person with SAD will experience all of the symptoms listed below.
Symptoms of major depression may include:
- Feeling depressed most of the day, nearly every day
- Losing interest in activities you once enjoyed
- Experiencing changes in appetite or weight
- Having problems with sleep
- Feeling sluggish or agitated
- Having low energy
- Feeling hopeless or worthless
- Having difficulty concentrating
- Having frequent thoughts of death or suicide
For winter-pattern SAD, additional specific symptoms may include:
- Oversleeping (hypersomnia)
- Overeating, particularly with a craving for carbohydrates
- Weight gain
- Social withdrawal (feeling like “hibernating”)
Specific symptoms for summer-pattern SAD may include:
- Trouble sleeping (insomnia)
- Poor appetite, leading to weight loss
- Restlessness and agitation
- Episodes of violent behavior
Bipolar disorder (formerly called manic-depressive illness or manic depression) is a mental illness that causes unusual shifts in a person’s mood, energy, activity levels, and concentration. These shifts can make it challenging to carry out day-to-day tasks.
There are three types of bipolar disorder. All three types involve clear changes in mood, energy, and activity levels. These moods range from periods of extremely “up,” elated, irritable, or energized behavior (known as manic episodes) to very “down,” sad, indifferent, or hopeless periods (known as depressive episodes). Less severe manic periods are known as hypomanic episodes.
- Bipolar I disorder is defined by manic episodes that last for at least seven days (nearly every day for most of the day) or by manic symptoms that are so severe that the person needs immediate medical care. Usually, depressive episodes occur as well, typically lasting at least two weeks. Episodes of depression with mixed features (having depressive symptoms and manic symptoms at the same time) are also possible. Experiencing four or more episodes of mania or depression within one year is called “rapid cycling.”
- Bipolar II disorder is defined by a pattern of depressive episodes and hypomanic episodes. The hypomanic episodes are less severe than the manic episodes in bipolar I disorder.
- Cyclothymic disorder (also called cyclothymia) is defined by recurring hypomanic and depressive symptoms that are not intense enough or do not last long enough to qualify as hypomanic or depressive episodes.
Sometimes, a person might experience symptoms of bipolar disorder that do not match the three categories listed above, and this is referred to as “other specified and unspecified bipolar and related disorders” (NIMH).
An estimated 4.4% of U.S. adults experience bipolar disorder at some time in their lives (NIMH).
What causes Bipolar Disorder?
Researchers are studying possible causes of bipolar disorder. Most agree that there are many factors that are likely to contribute to a person’s chance of having the disorder.
Brain structure and functioning: Some studies show that the brains of people with bipolar disorder differ in certain ways from the brains of people who do not have bipolar disorder or any other mental disorder. Learning more about these brain differences may help scientists understand bipolar disorder and determine which treatments will work best. At this time, health care providers base the diagnosis and treatment plan on a person’s symptoms and history, rather than brain imaging or other diagnostic tests.
Genetics: Some research suggests that people with certain genes are more likely to develop bipolar disorder. Research also shows that people who have a parent or sibling with bipolar disorder have an increased chance of having the disorder themselves. Many genes are involved, and no one gene causes the disorder. Learning more about how genes play a role in bipolar disorder may help researchers develop new treatments (NIMH).
Signs and Symptoms
When a person has a manic episode, they feel overly excited, productive, and even invincible. On the other hand, when a person has a depressive episode, they feel extremely sad, hopeless, and tired. They may avoid friends, family, and participating in their usual activities. A severe manic or depressive episode may trigger psychotic symptoms, such as delusions (false beliefs) or hallucinations (seeing or hearing things that others do not see or hear). These drastic behavior changes usually cause concern among friends and family. Everyone’s experience with bipolar disorder is different, and the signs and symptoms vary:
A “manic” episode may include:
- Intense feelings of euphoria, excitement, or happiness
- Appearing abnormally jumpy or wired
- Having excessive energy
- Insomnia or restlessness (a decreased need for sleep)
- Speaking fast or being unusually talkative
- Having racing or jumbled thoughts
- Inflated self-esteem
- Doing impulsive, uncharacteristic, or risky things like having unsafe sex or spending a lot of money
- Increased agitation and irritability
A “depressive” episode may include:
- Feeling down, sad, worried, worthless, anxious, guilty, empty, or hopeless
- Lack of interest, or no interest, in activities
- Feeling tired, low energy
- Difficulty concentrating
- Changes in sleep, either sleeping too much or too little
- Changes in appetite, either eating too much or too little
- Thoughts of death and/or suicide