Mood disorders are mental disorders characterized by periods of depression, sometimes alternating with periods of elevated mood.
While many people go through sad or elated moods from time to time, people with mood disorders suffer from severe or prolonged mood states that disrupt their daily functioning. Among the general mood disorders classified in the fourth edition (1994) of the Diagnostic and Statistical Manual of Mental Disorders (DSM–IV) are major depressive disorder,bipolar disorder, and dysthymia.
In classifying and diagnosing mood disorders, doctors determine if the mood disorder is unipolar or bipolar. When only one extreme in mood (the depressed state) is experienced, this type of depression is called unipolar. Major depression refers to a single severe period of depression, marked by negative or hopeless thoughts and physical symptoms like fatigue. In major depressive disorder, some patients have isolated episodes of depression. Between these episodes, the patient does not feel depressed or have other symptoms associated with depression. Other patients have more frequent episodes.
Bipolar depression or bipolar disorder (sometimes called manic depression) refers to a condition in which people experience two extremes in mood. They alternate between depression (the ‘‘low’’ mood) and mania or hypomania (the ‘‘high’’ mood). These patients go from depression to a frenzied, abnormal elevation in mood. Mania and hypomania are similar, but mania is usually more severe and debilitating to the patient.
Dysthymia is a recurrent or lengthy depression that may last a lifetime. It is similar to major depressive disorder, but dysthymia is chronic, long–lasting, persistent, and mild. Patients may have symptoms that are not as severe as major depression, but the symptoms last for many years. It seems that a mild form of the depression is always present. In some cases, people also may experience a major depressive episode in addition to their dysthymia, a condition sometimes referred to as a ‘‘double depression.’’
Causes and symptoms
Mood disorders tend to run in families. These disorders are associated with imbalances in certain chemicals that carry signals between brain cells (neurotransmitters). These chemicals include serotonin, norepinephrine, and dopamine. Women are more vulnerable to unipolar depression than are men. Major life stressors (such as divorce, serious financial problems, and death of a family member) often provoke the symptoms of depression in susceptible people.
Major depression is more serious than just feeling ‘‘sad’’ or ‘‘blue.’’ The symptoms of major depression may include:
- Loss of appetite
- A change in sleep patterns, such as not sleeping (insomnia) or sleeping too much
- Feelings of worthlessness, hopelessness, or inappropriate guilt
- Difficulty in concentrating or making decisions
- Overwhelming and intense feelings of sadness or grief
- Disturbed thinking.
- The person may also have physical symptoms such as stomach aches or headaches
Bipolar disorder includes mania or hypomania. Mania is an abnormal elevation in mood. The person may be excessively cheerful, have grandiose ideas, and may sleep less. He or she may talk nonstop for hours, have unending enthusiasm, and demonstrate poor judgement. Sometimes the elevation in mood is marked by irritability and hostility rather than cheerfulness. While the person may at first seem normal with an increase in energy, others who know the person well see a marked difference in behaviour. The patient may seem to be in a frenzy and often will make poor, bizarre, or dangerous choices in his/her personal and professional lives. Hypomania is not as severe as mania and does not cause the level of impairment in work and social activities that mania can.
Doctors diagnose mood disorders based on the patient’s description of the symptoms as well as the patient’s family history. The length of time the patient has had symptoms also is important. Generally patients are diagnosed with dysthymia if they feel depressed more days than not for at least two years. The depression is mild but long lasting. In major depressive disorder, the patient is depressed almost all day nearly every day of the week for at least two weeks. The depression is severe. Sometimes laboratory tests are performed to rule out other causes for the symptoms (such as thyroid disease). The diagnosis may be confirmed when a patient responds well to medication.
The most effective treatment for mood disorders is a combination of medication and psychotherapy. Individuals may have better results if they also participate in family-focused therapy. The four different classes of drugs used in mood disorders are:
- Tricyclic (Heterocyclic in US) antidepressants (TCAs or HCAs), such as amitriptyline (Elavil)
- Selective serotonin reuptake inhibitors (SSRI inhibitors), such as fluoxetine (Prozac), paroxetine (Seroxat, Paxil), and sertraline (Zoloft)
- Monoamine oxidase inhibitors (MAOI inhibitors), such as phenelzine sulfate (Nardil) and tranylcypromine sulfate (Parnate)
- Mood stabilizers, such as lithium carbonate (Eskalith) and valproate, often used in people with bipolar mood disorders.
A number of psychotherapy approaches are useful as well. Interpersonal psychotherapy helps the patient recognize the interaction between the mood disorder and interpersonal relationships. Cognitive–behavioural therapy explores how the patient’s view of the world may be affecting his or her mood and outlook. When depression fails to respond to treatment or when there is a high risk of suicide, electroconvulsivetherapy (ECT) sometimes is used. ECT is believed to affect neurotransmitters as medications do. Patients are anesthetized and given muscle relaxants to minimize discomfort. Then low–level electric current is passed through the brain to cause a brief convulsion. The most common side effect of ECT is mild, short–term memory loss.
There are many alternative therapies that may help in the treatment of mood disorders, including acupuncture, botanical medicine, homeopathy, aromatherapy, constitutional hydrotherapy,and light therapy. The therapy used is an individual choice. Short–term clinical studies have shown that the herb St. John’s wort (Hypericum perforatum) can effectively treat some types of depression. Though it appears very safe, the herb may have some side effects and its long–term effectiveness has not been proven. It has not been tested in patients with bipolar disorder. Despite uncertainty concerning its effectiveness, a 2003 report said acceptance of the treatment continues to increase. A poll showed that about 41% of 15,000 science professionals in 62 countries said they would use St. John’s wort for mild to moderate depression. Although St. John’s wort appears to be a safe alternative to conventional antidepressants, care should be taken, as the herb can interfere with the actions of some pharmaceuticals. The usual dose is 300 mg three times daily. St. John’s wort and antidepressant drugs should not be taken simultaneously, so patients should tell their doctor if they are taking St. John’s wort.
Most cases of mood disorders can be successfully managed if properly diagnosed and treated.
People can take steps to improve mild depression and keep it from becoming worse. They can learn stress management (such as relaxation training or breathing exercises), exercise regularly, and avoid drugs or alcohol.
Series of articles about mood disorders:
- Mood disorders - introduction and historical review - technical
- Mood disorders - clinical features of mood disorders and mania - technical
- Mood disorders - diagnosis, classification and differential diagnosis - technical
- The epidemiology of mood-disorders - technical
- Aetiology Article 1: The genetic and social aetiology of mood disorders - technical
- Aetiology Article 2: The neurobiological aetiology of mood disorders - technical
- The course and prognosis of mood disorders - technical
- The treatment of mood disorders - technical
- Dysthymia, cyclothymia, and related chronic subthreshold mood disorders - technical
- Mood disorders-historical introduction and conceptual overview - technical
- Types of psychological therapy - technical