Characteristics of Depression
We all know what it is like to feel sad. In fact, everyone has bad days from time to time when they feel somewhat down for no apparent reason. In the case of clinical depression, however, the feelings of sadness are intense and long lasting and are usually accompanied by feelings of physical depression:
- tiredness
- difficulty paying attention
- difficulty sleeping
- changes in eating patterns (in some cases overeating, in others eating very little)
Severely depressed individuals also tend to exhibit the “pessimistic cognitive style” which is characterized by:
- a lack of use of the self-serving bias (ie, blaming oneself for problems and failures while not taking credit for positive events or features of one’s life)
- ruminating on sad events
- feeling that the current situation is permanent and uncontrollable and that the sadness will never end
- (in some cases) entertaining thoughts of suicide
Sometimes a reason for depression. A common misconception about clinical depression is that an individual only suffers from depression as a disorder if the individual is depressed for no apparent reason. Certainly it is the case that some people become depressed under nothing more stressful or depressing than normal everyday life experiences. In other cases, however, there may have been, or there may be at that moment, a very obvious reason why the individual is depressed. Perhaps, for example, the individual has suffered a serious loss (such as the death of a child) or lost a job. Even if one can trace the depression to a life situation such as those, if the individual is intensely sad for an extended period of time, is unable to make life decisions, feels tired and doesn’t want to get out of bed, etc., the individual is clinically depressed and is in need of treatment.
Like a number of other psychological disorders, depression tends to be a cyclic disorder. About half of people who have a severe extended episode of depression will not experience any further episodes once their mood improves. Other people who suffer from depression, however, experience multiple episodes of depression, and the more episodes an individual has had, the more likely that person is to have another episode in the future.
Hereditary/Genetic Contributions to Depression
There is no question that depressing life experiences can contribute to the development of depression. There is also no question that some people are born more likely than others to develop depression. Our knowledge of the hereditary contribution to depression derives primarily from two kinds of studies: twin studies and adoption studies .
Adoption studies have shown that the rate of depression among adopted individuals is higher if the individual’s biological mother suffered from depression than if the individual’s adoptive mother suffered from depression. Twin studies examine the “concordance rate” for depression. Concordance rate refers to the rate at which one member of a twin pair suffers from depression given that the other member of the twin pair is already known to suffer from depression.
Twin studies involve comparing the concordance rate for identical twins in comparison with the concordance rate for fraternal twins. The logic of this comparison is based upon the fact that identical twins are genetic clones of each other, whereas fraternal twins are no more similar to each other genetically than are non-twin siblings. Thus, if there is a genetic contribution to depression, then the concordance rate should be higher for identical twins than for fraternal twins. It is. It should be noted, however, that even for identical twins, the concordance rate is only about 40 percent, indicating that life experiences also contribute to the development of the disorder.
Manic-Depressive Disorder (AKA Bipolar Disorder)
Some people experience periods of both depression and mania. Mania is in many ways the opposite of depression. During a manic episode, the individual is very energetic, very optimistic, and has high feelings of self-esteem. So-what’s wrong with that?
In fact, some people who suffer from bipolar disorder accomplish a great deal during their episodes of mania. The problem is that the manic episodes will be balanced by usually severe periods of depression. In addition, what the person sets out to do or accomplish during periods of mania may be so unrealistic that there is no chance that the ambitions of the manic episode can be realized. Many people with bipolar disorder make a lot of irrationally optimistic plans when they are manic, but there is a big difference between making plans or beginning a long and difficult project on the one hand and actually accomplishing something important on the other.
Bipolar disorder is much less common than depression. Whereas some have estimated that as many as 10 percent of adults in the U.S. will experience depression during any particular year, and close to twice that many will have at least one episode of clinical depression in their lifetime, only about 1 to 2 percent of the population suffers from bipolar disorder. In addition, whereas clinical or major depression occurs twice as often in females as males, bipolar disorder occurs at similar rates in males and females.
Biological Treatments for Depression and Bipolar Disorder
If you are diagnosed with major depression, the chances are very high that you will be put on a regimen of antidepressant medication. The medication will be used to help bring you out of your episode of severe depression, and will then be used to help ward off future episodes of depression. Millions of adults in the U.S. take antidepressant medication every day of their adult lives.
Antidepressant drugs affect levels of neurotransmitters. Currently the most popular antidepressant medications (Prozac, for example) are “selective serotonin reuptake inhibitors” (SSRIs). These drugs block the normal reuptake of the neurotransmitter serotonin by the neurons that have released them, thereby increasing the amount of serotonin in the synaptic gap. This process within the brain begins with the first dosage of the medication. For reasons that are not well understood, however, the drug’s effects on the patient’s mood usually takes several weeks to occur. Medication is also used for the treatment of bipolar disorder, although different types of drugs are used for the treatment of bipolar disorder than are used for the treatment of major unipolar depression.
A second, somewhat controversial, biological form of treatment for major depression is electro-convulsive therapy (ECT), a treatment you have probably heard referred to colloquially as “shock therapy.” ECT involves running a series of low voltage shocks of electricity through the brain. ECT is not a treatment of first choice for depression. However, if a patient is severely depressed, drugs are not helping, and the patient is suicidal, ECT may be recommended. It is not known how it works, but the evidence is clear than it often does help bring such individuals out of their severe episode of depression. ECT has not been found to be an effective form of treatment for any disorder other than depression.
