The depressive disorders are characterized by a persistent sad or unhappy mood. Sometimes these disorders are referred to as the unipolar depressions. The current version of the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision (DSM-IV-TR), published by the American Psychiatric Association (2000), identifies two primary depressive disorders: major depressive disorder (MDD) and dysthymic disorder (DD). MDD is an acute form of depression in which the individual is extremely sad, discouraged, or blue for at least 2 weeks. In contrast, DD involves a chronically depressed mood of at least 2 years in adults, and of at least 1 year in children. Thus, MDD is distinguished by its severity, whereas DD is notable for its chronicity. MDD and DD can have their onset at any point in life, and there is a substantial overlap of symptomatology between the two disorders.
There are a number of key psychological symptoms observed in both MDD and DD. First and foremost, individuals with these disorders display depressed mood, in which the person is sad, hopeless, or down in the dumps. In younger children, depressed mood may emerge as irritability, crankiness, and destructive behaviors, rather than as the sad affect typically observed in adults. Also, depressed individuals may display anhedonia, or a loss of interest in normally pleasurable activities. For example, an adult may report losing interest in hobbies or decreased sex drive. Likewise, parents may describe a depressed child as socially withdrawn. Another psychological symptom often seen in depression is psychomotor agitation/retardation. In psychomotor agitation, the person may pace or wring his or her hands. In psychomotor retardation, the individual may have slowed speech or body movements. Additionally, feelings of worthlessness and guilt are commonly seen in depression. For example, depressed people may be overly self-critical, exaggerate their responsibility for negative events, or focus on their personal failings. Finally, thoughts of death and suicidal behavior are sometimes seen in individuals who are depressed. Indeed, depressed people may think about dying or about suicide, and in some instances may even have a plan for killing themselves.
In addition to these psychological indicators, there is also a range of biological symptoms associated with depression. For example, depressed individuals may experience appetite changes that produce substantial weight loss or weight gain. Also, sleep disturbances may be noted. The most common of these is terminal insomnia, in which the person wakes up a few hours too early each morning and is unable to fall back asleep. Energy disturbances such as chronic tiredness or fatigue upon mild physical exertion are a common biological symptom of depression. Finally, many individuals who are depressed often say that they that have difficulty concentrating. For example, they may complain of being easily distracted or of problems remembering things.
Depression can begin at any point in life, although the most common age of onset is in the mid-twenties. The symptomatology of depression tends to vary across the life span. In children, certain symptoms are more common, such as irritability, social withdrawal, and somatic complaints (e.g., stomachaches). Sleep problems and psychomotor retardation are rarely observed in young people. In contrast, depressed adults are more likely to evidence the classic symptom of depressed affect, along with the full range of symptomatology described earlier.
Depression is a very common disorder and approximately 20% of adults will experience at least one episode of depression in their lives. Depression is less common among young people, with prevalence rates ranging between only 1% and 8% of children. More females than males evidence depression, although this gender difference is not apparent until puberty.
Theories Of Etiology
The predominant etiological models used to understand the causes of depression include the psychoanalytic, cognitive, behavioral, interpersonal, and biological perspectives. Each of these etiological models is briefly summarized here.
Psychoanalytic Theory of Depression
According to Freud, depression has its origins in childhood. Freud hypothesized that when a child experiences loss through separation or withdrawal of affection, he or she begins to harbor negative feelings toward that person. Eventually, the child’s anger toward the loved one is turned inward. Consequently, the classic psychoanalytic view of depression involves anger turned inward against the self. In contrast, modern psychoanalytically oriented attachment theorists believe that disruption of the infant caretaker bond early in life (e.g., at 18 months) can produce a vulnerability to developing depression later in life.
Beck’s Cognitive Theory of Depression
In cognitive explanations of depression, thoughts and beliefs are considered to have a major role in causing or influencing the emotional state. According to Beck, depression results from faulty schemata or belief systems about the self and world. These negative schemata are evident in a pattern of thinking called the negative triad, which involves a negative view of the self, the world, and the future. Negative schemata produce characteristic distortions in thinking, such as the tendency to magnify the potential consequences of a negative event. Later in life, individuals filter events through these cognitive distortions, which can lead to depression.
Helplessness and Hopelessness Theories
According to the learned helplessness theory, an individual’s sense of being unable to act or control aversive events results in expectations of helplessness, in turn leading to depression. Eventually, this model evolved into the hopelessness theory of depression. Hopelessness, or a general expectation that negative events will occur and that nothing can be done about them, is said to be the cause of some types of depression. Hopelessness results from the different kinds of inferences that a person makes about negative life events. These inferences include the causes of the event, the consequences of the event, and the self.
Interpersonal Theory of Depression
Depressed individuals tend to have few social networks and perceive them as providing little support. This reduced social support can lessen an individual’s ability to cope with negative life events, making these people even more susceptible to depression. Furthermore, depressed individuals tend to elicit more negative reactions from others, thereby validating their negative self-concept.
Biological Theories of Depression
Several biological causes have been implicated in the etiology of depression. It is well known that depression tends to run in families. Twin studies have shown higher concordances of depression in monozygotic than in dizygotic twins, suggesting a genetic component. Additionally, the effectiveness of drug therapies for depression suggests a biological component. Furthermore, levels of the stress hormone cortisol are higher in depressed persons than in those who are not depressed. These various sources of evidence suggest a strong biological underpinning to depression.
Treatment Of Depression
According to psychoanalytic theory, depression results from feelings of loss and anger that have been turned inward by the individual. Therefore, the goal of psychoanalytic therapy is to help the patient to uncover the unconscious sources of his or her depression. During therapy, the patient works to uncover these feelings of loss and anger and is then able to achieve insight into his or her feelings and express the unconscious conflicts. Unfortunately, there have been few controlled studies evaluating the effectiveness of psychoanalysis for treating depression.
Beck’s Cognitive Therapy
According to Beck, errors in an individual’s thinking are the cause of poor self-esteem and depression. The goal in cognitive therapy is to change the patients’ maladaptive ways of thinking by teaching him or her new, more successful thought patterns. The patient is active in his or her own treatment by learning to monitor internal monologues and to identify distorted thought patterns that contribute to depression. Much research has been done evaluating the efficacy of Beck’s cognitive therapy, and evidence suggests it is helpful in alleviating depression.
Social Skills Training
This therapy focuses on enhancing the social skills of a depressed individual, thus helping the patient have more enjoyable social interactions and experiences with others. The patient learns new ways to interact with others, such as the ability to stand up for one’s rights through assertiveness training.
Antidepressant medication is the most commonly used biological treatment for depression. There are three major categories of drugs: (a) tricyclics, (b) selective serotonin reuptake inhibitors (SSRIs), and (c) monoamine oxidase inhibitors (MAOIs). The tricyclics and SSRIs work by blocking the reuptake of neurotransmitters such as serotonin, whereas the MAOIs work by blocking the action of an enzyme that breaks down the key neuorotransmitters. Although the effectiveness of all three classes of drugs is similar, the SSRIs, which include Prozac and Zoloft, are associated with fewer side effects.
Electroconvulsive therapy (ECT) is sometimes used with patients who do not respond to medication or who are severely depressed. The procedure involves inducing a seizure in the patient by passing 70 to 130 volts of electricity through the right hemisphere of the brain. Unfortunately, the side effects of ECT include memory loss and confusion, but it may be the best treatment when all other therapies have failed.
Recently, individuals suffering from depression have sought new avenues of relief. Some of these therapies include exercise, which has been found to be successful in treating depression. Also, a B vitamin called folate, when administered with drug therapy, can enhance the effectiveness of antidepressants and reduced the side effects associated with the drugs. Additionally, the herbal supplement Saint Johns work has been shown to be as effective as antidepressants in alleviating depression, although the mechanism of action is not clearly understood.
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- Milling, S. (2001). Depression in preadolescents. In C. E. Walker & C. Roberts (Eds.), Handbook of clinical child psychology (3rd ed., pp. 373–413). New York: Wiley.
- National Institute of Mental Health. (2004). DeprRetrieved from http://www.nimh.nih.gov/publicat/depression.cfm