Mood Disorders

Mood disorders are among the most common mental disorders in the Western world. Formerly called affective disorders, these disorders involve a predominant disturbance in mood. In each case, the mood disturbance leads to other problems, which frequently include physical symptoms (such as fatigue), behavioral symptoms (such as social withdrawal), and cognitive symptoms (such as self-critical thoughts). The various mood disorders differ based on the type and duration of symptoms. Severe mood disorders develop from a combination of biological, stressful experiences and personality types or interpersonal factors. Treatment options usually include a combination of medication and psychotherapy.

The various mood disorders can be distinguished based on the nature of the mood disturbance, the severity of symptoms, and their duration. The depressive disorders (sometimes known as unipolar disorders) are primarily characterized by a sad mood or a profound loss of enjoyment in most activities. In younger persons, the mood may be irritable rather than despondent. The depressed mood is often experienced as sadness, tearfulness, discouragement, and feeling “down in the dumps.” In some cases, the person may complain of feeling emotionless. The loss of enjoyment or loss of pleasure, called anhedonia, is virtually always present to some extent in the depressive disorders; it is often experienced as a loss of interest in one’s hobbies and usual activities. A reduction in sex drive is another common experience.

Other common symptoms of depressive disorders include sleep problems, low energy, and changes in appetite. Common sleep problems include insomnia in the form of nighttime waking and difficulty returning to sleep or early morning waking. Because of low energy and fatigue, the smallest tasks may seem overwhelming. Changes in appetite may be so profound as to cause extreme unintended changes in weight, usually weight loss, over a short period of time. During periods of depressed mood, cognitions frequently involve a sense of worthlessness and excessive guilt. Trivial events may be misinterpreted as proof of one’s inadequacy, consistent with the negative mood. Decision making and concentration are compromised. Thoughts about death and suicide are common.

The disturbance in bipolar disorders involves periods of depressed mood and separate periods in which the mood is abnormally elevated. The signs of a manic mood include feelings of euphoria, a “high,” or an abnormally cheerful mood. The mood may rapidly turn to irritability if others are perceived as interfering with the individual’s plans. Inflated self-esteem occurs invariably; it may range from boastful self-confidence to grandiose delusions, such as having the firm belief that one has supernatural powers.

Many symptoms of the manic phases of bipolar disorders are opposite to those experienced in the depressive disorders. In a manic phase, the individual may demonstrate an uninhibited enthusiasm for pleasurable activities, which could include irresponsible spending sprees and indiscriminate sexual pursuits. The need for sleep is markedly reduced and surplus energy abounds. In a manic phase of bipolar disorder, a person may speak in an incessant, rapid, and loud manner. Thoughts may flow at such a rapid pace that the person may seem unable to keep up with them, a phenomenon known as flight of ideas. Excess energy, combined with unbridled enthusiasm and a euphoric mood, often lead unknowing observers to conclude that the individual is under the influence of a stimulant drug, such as cocaine. Indeed, many of the symptoms of bipolar disorder seem excessive and uncontained.

Types of Mood Disorders

The most prevalent depressive disorder, known as major depressive disorder, corresponds loosely to the popular concept of a clinical depression. At the very minimum, major depressive disorder involves experiencing one episode of deep depression characterized by a sad mood or loss of enjoyment in life. Other common symptoms include sleep problems, fatigue, feelings of worthlessness, and suicidal thoughts. The depressive episode will typically last for months, during which the person experiences these problems most of the time. The symptoms usually remit 6 to12 months after the onset. There is, however, a significant chance of future depressive episodes. A significant number of people who have recovered from major depressive disorder will have recurrent episodes although these can occur years apart. Major depressive disorder is usually first experienced in late adolescent or early adulthood. Nearly 17% of the U.S. population is likely to experience major depressive disorder, and the rates are twice as high for women as for men.

Major depressive disorder can take many varied forms. The variant with psychotic features involves an unusually severe form of depression accompanied by auditory hallucinations (such as hearing accusing or insulting voices), delusional beliefs, and overwhelming feelings of guilt. The melancholic form, which is more common in older adults, is characterized by early morning waking, weight loss, and anhedonia. The seasonal pattern describes a cyclical form of depression that recurs every fall or winter and involves weight gain and excessive sleep. The seasonal mood disturbance typically lifts in the spring.

Dysthymic disorder is a mild but long-lasting depressive disorder. Whereas the duration of major depressive disorder is measured in months, dysthymic disorder is evident over several years (the minimum is 2 years). Low self-esteem, loss of pleasure, social avoidance, and poor concentration are typical symptoms. The onset of dysthymic disorder is gradual and occurs at an early age.

The types of bipolar disorders are mostly distinguished on the basis of the manic symptoms. The most well-known is Bipolar Disorder Type 1, which was formerly called manic depression. It involves multiple recurrent episodes of depression and mania. The manic episodes, which are shorter, usually either precede or follow a severe depressive spell. Mood may temporarily return to normal between episodes. Bipolar Disorder Type 1 is less prevalent than major depressive disorder, affecting fewer than 2% of the population; the gender ratio is equal. Bipolar Disorder Type 2 is similar with the exception that it does not involve full-blown manic symptoms. The mild manic episodes, or hypomania, evidence bursts of energy, elevated or irritable mood, and poor judgment, but without the extremes of a full-blown manic episode. Cyclothymic disorder, the mildest bipolar disorder, involves chronic and fluctuating mood changes. The severity and duration of these mild mood changes are less than those witnessed in major depressive disorder or Bipolar Disorder Type 1, yet they are serious enough to cause disruptions in important areas of life and to cause significant unhappiness. To an outsider, the person with cyclothymic disorder may come across as abnormally moody.

Mood Disorders and Suicide

Suicide is the conscious and deliberate taking of one’s own life. Worldwide, it is one of the top 10 leading causes of death. More than 31,000 individuals die by suicide in the United States annually, and an additional 600,000 people attempt suicide each year. The fatality figures are probably underestimates because some suicidal deaths are mistaken for accidents and surviving family members are often reluctant to label the deaths as intentional because of stigma or guilt.

The rates of suicide vary significantly according to age, gender, occupation, life situation, and health. Many young adults, as many as 1 in 10, have seriously contemplated suicide. However, the highest rates of completed suicides occur in older adults above the age of 65. Women are more likely than men to attempt suicide, but men are more likely to die of suicide because they tend to use more lethal methods. Whereas suicidal women often rely on overdosing or cutting their wrists, men tend to use firearms or hanging. People in the midst of relationship problems, such as separation or divorce, have higher suicide rates, as do people with terminal illnesses. As many as 15% of persons with mood disorders will commit suicide, and the risk is particularly high during or following an episode of severe depression.

Suicide rates also vary across ethnic and racial groups in the United States. For example, Native Americans have the highest rates of suicide, while White men have the second highest rates. The risk is relatively lower for Black women. Creative or successful scientists, artists, and professionals have a higher-than-average lifetime suicide risk.

Suicide is best understood as a desperate act designed to end seemingly inescapable emotional, physical, or interpersonal suffering. Some suicidal gestures are also intended to convey to others the depth of one’s despair, as a “cry for help.” Most persons who have suicidal thoughts experience some ambivalence; this is often reflected in the chosen method and in prior communications of intentions. The majority of people who commit suicide have previously communicated their suicidal intent with others, often in explicit terms. However, highly distressed persons who are determined to die will use highly lethal methods and are unlikely to have shared their intentions with others. Using a very deadly method without sharing the plan with others nearly guarantees that it will be successful.

Suicide notes can be useful for understanding the motives and desperation that drive suicidal gestures. Approximately one-third of individuals who commit suicide do leave behind a note, usually for the benefit of surviving relatives and friends. Many notes are brief and to the point, and they betray profound distress. Suicide notes may be designed to explain the act or relieve surviving relatives’ feelings of guilt.

Causes of Mood Disorders

Biological Factors

It has long been known that severe mood disorders run in families, which suggests that heredity plays a role in their development. The rates of mood disorders are nearly three times higher than average among the blood relatives of persons with depressive disorders. Studies of twins, of which one has a mood disorder, show a higher rate of mood disorders among identical twins than among fraternal twins. Heredity plays a greater role in the causation of bipolar disorders. Twin studies reveal that approximately two-thirds of identical twins who have bipolar disorder have a co-twin who shares a mood disorder. In fact, the best predictor of a person’s risk of developing a Bipolar Disorder is having a family history. Biological factors, however, play a smaller role in the onset of minor mood disorders.

A growing body of research reveals that severe mood disorders are related to abnormalities in the brain areas that regulate emotions and basic biological needs, such as hunger and sleep. Problems with the brain’s internal biological clock are related to inefficiencies in the brain’s chemistry. There is evidence that the brain’s own chemical signals, known as neurotransmitters, are not functioning properly in persons with severe depression. It is believed that imbalances in the brain’s chemical signals, combined with disruptions in the sequencing of the brain’s biological clock, may account for most of the common symptoms of mood disorders. Specifically, the disruptions in the internal clock could lead to problems with sleep, energy, and loss of enjoyment. Some people may be especially vulnerable to these problems, either because of their family history or because of other nongenetic risk factors.

Life Experiences

The link between stressful life experiences and depression is well established. Several specific stressful events seem to be especially troubling for persons who are prone to mood disorders. Major losses, such as the death of a loved one or financial losses, often precede significant depression. Losses that are ego threatening (such as a divorce or job termination) are usually difficult for persons who are at risk for mood disorders, especially if they feel personally responsible for the event. In other words, being fired from a job for poor performance will be more threatening than losing a job to downsizing. Chronic and ongoing stressors also increase the risk of becoming depressed, in contrast to an abrupt and isolated source of stress.

Personality and Interpersonal Factors

Certain personality traits, such as negative affectivity, may help predict a person’s risk of developing a depressive disorder in the face of stressful life events. Negative affectivity is a personality type that is prone to negative emotions, including worry, anxiety, and sadness. Because of this proneness to negative emotions, the individual is ill equipped to deal with major losses or threats to the ego. From another perspective, it is suggested that some people are prone to depression because of distorted beliefs about themselves, the world, and the future. Rigid and distorted beliefs become activated by stressful experiences, causing the person to blow events out of proportion and feel personally responsible for failure and disappointment. According to this viewpoint, negative and self-critical thoughts are directly related to the onset of depression following a stressful life event.

Additionally, a number of interpersonal problems are linked with the risk for depressive disorders. Individuals who are socially isolated and those who lack the social skills for maintaining rewarding relationships are at high risk for depression. Once depressed, pessimism and negative thinking may further isolate the individual from other people who are trying to avoid the negativity, setting up a self-perpetuating cycle. The importance of interpersonal factors in the causation of depressive disorders is further highlighted by the strong association between marital distress and depression. Separation and divorce are common antecedents of depression, as is ongoing marital conflict. The direction of cause, however, is not always obvious—relationship problems could cause depression or the reverse could occur. Alternatively, a separate factor, such as negative affectivity, could be responsible for both depression and relationship problems.

Treatment of Mood Disorders

The two major approaches to treatment of the mood disorders include medication and therapy. For bipolar disorders, medication is the first line of treatment. It usually consists of a mood stabilizer, which reduces the frequency and intensity of manic episodes, often in combination with an antidepressant. Approximately 75% of individuals with a bipolar disorder who comply with medication will experience some improvement. The amount of improvement, however, is variable, ranging from mild to dramatic. Supportive therapy and family therapy may be helpful supplements for patients with severe bipolar disorder. The unpleasant side effects of mood stabilizers, such as drowsiness, upset stomach, and impaired coordination, along with the stigma of taking medication for a mental disorder, cause problems with medication compliance in many cases of bipolar disorder.

The depressive disorders are often treated with a combination of antidepressant medication and psychotherapy. Approximately two-thirds of patients will benefit from antidepressant medications such as Prozac (fluoxetine is the generic name), although it may take several weeks before any improvement is noticed. The newer antidepressant medications produce relatively few side effects; however, it is not uncommon to experience a decline in sex drive and feelings of restlessness.

Cognitive therapy for depression is one of the best documented treatments. Several large-scale studies show that its effectiveness rivals medication in the long term. Additionally, unlike medication, cognitive therapy can reduce a person’s risk for future depressive episodes. As a brief and structured form of treatment, cognitive therapy is designed to help the patient identify and modify distorted thinking. Marital and family therapy may be useful for severe mood disorders that are related to conflict at home.


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