Definition
Depression, also known as depressive disorders or unipolar depression, is a mental illness characterized by a profound and persistent feeling of sadness or despair and/or a loss of interest in things that once were pleasurable. Disturbance in sleep, appetite, and mental processes are a common accompaniment.
Description
Everyone experiences feelings of unhappiness and sadness occasionally. However, when these depressed feelings start to dominate everyday life without a recent loss or trauma and cause physical and mental deterioration, they become what is known as depression. Each year in the United States, depression affects an estimated 17 million people at an approximate annual direct and indirect cost of $53 billion. One in four women is likely to experience an episode of severe depression in her lifetime, with 10-20% lifetime prevalence, compared to 5-10% for men. The average age a first depressive episode occurs is in the mid-20s, although the disorder strikes all age groups indiscriminately, from children to the elderly.
There are two main categories of depression: major depressive disorder and dysthymic disorder. Major depressive disorder is a moderate to severe episode of depression lasting two or more weeks. Individuals experiencing this major depressive episode may have trouble sleeping, lose interest in activities in which they once took pleasure, experience a change in weight, have difficulty concentrating, feel worthless and hopeless, or have a preoccupation with death or suicide. In children, major depression may appear as irritability.
While major depressive episodes may be acute (intense but short-lived), dysthymic disorder is an ongoing, chronic depression that lasts two or more years (one or more years in children) and has an average duration of 16 years. The mild to moderate depression of dysthymic disorder may rise and fall in intensity, and those afflicted with the disorder may experience some periods of normal, nondepressed mood of up to two months in length. Its onset is gradual, and dysthymic patients may not be able to pinpoint exactly when they started feeling depressed. Individuals with dysthymic disorder may experience a change in sleeping and eating patterns, low self-esteem, fatigue, trouble concentrating, and feelings of hopelessness.
Depression also can occur in bipolar disorder, an affective mental illness that causes radical emotional changes and mood swings, from manic highs to depressive lows. The majority of bipolar individuals experience alternating episodes of mania and depression.
Causes & symptoms
The causes behind depression are complex and not yet fully understood. While an imbalance of certain neurotransmitters, the chemicals in the brain that transmit messages between nerve cells, is believed to be key to depression, external factors such as upbringing (more so in dysthymia than major depression) may be as important. For example, it is speculated that, if an individual is abused and neglected throughout childhood and adolescence, a pattern of low self-esteem and negative thinking may emerge, and from that, a lifelong pattern of depression may follow. A 2003 study reported that two-thirds of patients with major depression say they also suffer from chronic pain.
Heredity seems to play a role in who develops depression. Individuals with major depression in their immediate family are up to three times more likely to have the disorder themselves. It would seem that biological and genetic factors may make certain individuals predisposed or prone to depressive disorders, but environmental circumstances may often trigger the disorder.
External stressors and significant life changes, such as chronic medical problems, death of a loved one, divorce or estrangement, miscarriage, or loss of a job also can result in a form of depression known as adjustment disorder. Although periods of adjustment disorder usually resolve themselves, occasionally they may evolve into a major depressive disorder.
Major depressive episode
Individuals experiencing a major depressive episode have a depressed mood and/or a diminished interest or pleasure in activities. Children experiencing a major depressive episode may appear or feel irritable, rather than depressed. In addition, five or more of the following symptoms will occur on an almost daily basis for a period of at least two weeks:
- Significant change in weight
- Insomnia or hypersomnia (excessive sleep)
- Psychomotor agitation or retardation
- Fatigue or loss of energy
- Feelings of worthlessness or inappropriate guilt
- Diminished ability to think or to concentrate, or indecisiveness
- Recurrent thoughts of death, or suicidal and/or suicide attempts
Dysthymic disorder
Dysthymia commonly occurs in tandem with other psychiatric and physical conditions. Up to 70% of dysthymic patients have both dysthymic disorder and major depressive disorder, known as double depression. Substance abuse, panic disorders, personality disorders, social phobias, and other psychiatric conditions also are found in many dysthymic patients. Dysthymia is prevalent in patients with certain medical conditions, including multiple sclerosis, AIDS, hypothyroidism, chronic fatigue syndrome, Parkinson’s disease, diabetes, and postcardiac transplantation. The connection between dysthymic disorder and these medical conditions is unclear, but it may be related to the way the medical condition and/or its pharmacological treatment affects neurotransmitters. Dysthymic disorder can lengthen or complicate the recovery of patients also suffering from medical conditions. Along with an underlying feeling of depression, people with dysthymic disorder experience two or more of the following symptoms on an almost daily basis for a period for two or more years (most suffer for five years), or one year or more for children:
- Under or overeating
- Insomnia or hypersomnia
- Low energy or fatigue
- Low self-esteem
- Poor concentration or trouble making decisions
- Altered libido
- Altered appetite
- Altered motivation
- Feelings of hopelessness
Diagnosis
The guidelines for diagnosis of major depressive disorder and dysthymic disorder are found in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM IV). In addition to an interview, several clinical inventories or scales may be used to assess a patient’s mental status and determine the presence of depressive symptoms. Among these tests are: the Hamilton Depression Scale (HAM-D), Child Depression Inventory (CDI), Geriatric Depression Scale (GDS), Beck Depression Inventory (BDI), and the Zung Self- Rating Scale for Depression. These tests may be administered in an outpatient or hospital setting by a general practitioner, social worker, psychiatrist, or psychologist.
Treatment
Depression usually is treated with antidepressants and/or psychosocial therapy. When used together correctly, therapy and antidepressants are a powerful treatment plan for the depressed patient.
Drugs
Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine (Prozac) and sertraline (Zoloft), reduce depression by increasing levels of serotonin, a neurotransmitter. Some clinicians prefer SSRIs for treatment of dysthymic disorder. Anxiety, diarrhea, drowsiness, headache, sweating, nausea, poor sexual functioning, and insomnia all are possible side effects of SSRIs. A recent study shows this generation of drugs increases patients’ risk of gastrointestinal bleeding. Tricyclic antidepressants (TCAs) are less expensive than SSRIs, but have more severe side effects including persistent dry mouth, sedation, dizziness, and cardiac arrhythmias. Because of these side effects, caution is taken when prescribing TCAs to elderly patients. TCAs include amitriptyline (Elavil), imipramine (Tofranil), and nortriptyline (Aventyl, Pamelor). A 10-day supply of TCAs can be lethal if ingested all at once, so these drugs may not be a preferred treatment option for patients at risk for suicide.
Monoamine oxidase inhibitors (MAO inhibitors), such as tranylcypromine (Parnate) and phenelzine (Nardil), block the action of monoamine oxidase (MAO), an enzyme in the central nervous system. Patients taking MAOIs must avoid foods high in tyramine (found in aged cheeses and meats) to avoid potentially serious hypertensive side effects. Heterocyclics include bupropion (Wellbutrin) and trazodone (Desyrel). Bupropion is prescribed to patients with a seizure disorder. Side effects include agitation, anxiety, confusion, tremor, dry mouth, fast or irregular heartbeat, headache, low blood pressure, and insomnia. Because trazodone has a sedative effect, it is useful in treating depressed patients with insomnia. Other possible side effects of trazodone include dry mouth, gastrointestinal distress, dizziness, and headache. In 2003,Wellbutrin’s manufacturer released a once-daily version of the drug that offered low risk of sexual side effects or weight gain.
Electroconvulsive therapy
ECT, or electroconvulsive therapy, usually is employed after all therapy and pharmaceutical treatment options have been explored and exhausted. However, it is sometimes used early in treatment when severe depression is present and the patient refuses oral medication, or when the patient is becoming dehydrated, extremely suicidal, or psychotic.
The treatment consists of a series of electrical pulses that move into the brain through electrodes on the patient’s head. ECT is given under general anesthesia and patients are administered a muscle relaxant to prevent convulsions. Although the exact mechanisms behind the success of ECT therapy are not known, it is believed that the electrical current modifies the electrochemical processes of the brain, consequently relieving depression. Headaches, muscle soreness, nausea, and confusion are possible side effects immediately following an ECT procedure. Memory loss, typically transient, has also been reported in ECT patients. ECT causes severe memory problems for months or years in one out of every 200 patients treated.
Late in 2001, a study reported on a pacemaker-like device used to treat epilepsy adapted for patients with depression. An implanted electronic device sends intermittent signals to the vagus nerve, which in turn carries the signals to the brain, connecting in areas known to regulate mood. Although still experimental at this time, early results in treating depression have been encouraging.
Expected results
Untreated or improperly treated depression is the number one cause of suicide in the United States. Proper treatment relieves symptoms in 80-90% of depressed patients. After each major depressive episode, the risk of recurrence climbs significantly-50% after one episode, 70% after two episodes, and 90% after three episodes. For this reason, patients need to be aware of the symptoms of recurring depression and may require long-term maintenance treatment.
Overall, recent recommendations from mental health clinicians suggest that the recovery process for patients with depression works best when mental health professionals focus on the whole person behind the disorder. In addition to prescribing medications, they also should address a patient’s self-esteem, feeling of control, and determination. They emphasize that patients with depression need a sense of optimism and should be encouraged to seek the support of family members and friends.
Prevention
Patient education in the form of therapy or self-help groups is crucial for training patients with depressive disorders to recognize early symptoms of depression and to take an active part in their treatment program. Extended maintenance treatment with antidepressants may be required in some patients to prevent relapse. Early intervention with children with depression is effective in halting development of more severe problems.
