Depressive disorders, which pose a substantial risk of death and disability and are associated with suicide and poor work productivity, affect about eight percent of adults. Moreover, close to twenty percent of adults will suffer from some type of mood disorder that requires treatment during their lifetime. Mood disorders often have tragic results -- 15 percent of those affected commit suicide.
Depression, a common type of depressive disorder, is responsible for about 66 percent of all suicides. The disease occurs twice as often in women as in men and the risk increases if depression is present in an immediate family member. As the leading cause of premature death and disability in people between the ages of 18 and 44 years, it is surprising that there are no universally accepted diagnostic criteria for depression.
There are often errors in the diagnosis or treatment of the disease, and only 33 percent of depressed patients receive proper treatment. These errors are associated with insufficient questioning of the patient leading to diagnostic failure; failure to receive adequate information regarding the patients symptoms from family members; diagnosing a mood disorder and starting treatment despite a lack of diagnostic criteria; attempting to blame depression on stressful events, rather than diagnosing or treating the disease.
One set of diagnostic criteria commonly used to assess depression is known as "SIGECAPS" (see table below). This stands for sleep, interest, guilt, energy, concentration, appetite, psychomotor and suicide. If four or more of these items are a concern, it indicates major depression. However, other criteria, such as watching for symptoms other than just mood change and obtaining supporting information from family members, is important.
| Diagnostic criteria for major depressive disorder* |
| A. |
The patient has depressed mood (e.g., sad or empty feeling) or loss of interest or pleasure most of the time for 2 or more weeks plus 4 or more of hte following symptoms: |
| |
Sleep
|
Insomnia or hypersomnia nearly every day |
| |
Interest |
Markedly diminshed interest or pleasure in nearly all activities most of the time |
| |
Guilt |
Excessive or inappropriate feelings of guilt or worthlessness most of the time |
| |
Energy |
Loss of energy or fatigue most of the time |
| |
Concentration |
Diminished ability to think or concentrate; indecisiveness most of the time |
| |
Appetite |
Increase or decrease in appetite |
| |
Psychomotor |
Observed psychomotor agitation/retardation |
| |
Suicide |
Recurrent thoughts of death/suicidal ideation |
| B. |
The symptoms do not meet crieteria for mixed episode (major depressive episode and manic episode) |
| C. |
The symptoms cause clinically significant distress or impairment in social, occupational, or other improtant areas of functioning |
| D. |
The symptoms are not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication) or a general medical condition |
|
E. |
The symptoms are not better accounted for by bereavement |
| *Adapted from the Diagnostic and Statistical Manual of Mental Disorders, 4th edition. | |
The cause of depression is thought to be a disruption of the brain’s neurochemistry. Central norepinephrine neural pathways in the brain play a role in vigilance, motivation and energy levels. These pathways are associated with serotonin neural pathways, which are involved in controlling impulsivity, and share a role with the dopamine pathways in appetite, sex and aggression.
Depression is expected to be the second leading cause of disability for people of all ages by 2020. In general, an unhealthy lifestyle is more common among those depressed than those who are not. Additionally, children of those with depression are thought to have increased rates of behavior problems and lower levels of self-esteem than children with mothers who do not have depression.
In cases of moderate to severe major depression, antidepressant drugs are often used for treatment. Typically, about 60 percent of patients respond to the treatment, with the amount reaching 80 percent when a second drug is tried if the initial antidepressant drug fails. The goal of treatment is a full remission of symptoms, which may take up to four months. Patient recovery is not linear, however, as symptoms may reoccur after resolving.
Current guidelines suggest that antidepressant therapy should continue for at least six months after recovery in order to lessen the chance of a recurrence of depression, which occurs in more than 70 percent of patients.
Maintenance therapy, using antidepressant therapy for an indefinite amount of time, is considered as a treatment option for those who have additional risk factors of depression, such as especially difficult episodes or two or more episodes in a five-year period. The therapy’s goal is to prevent recurrence of the illness, however, costs and side effects of continued medication should be reviewed.
Another therapy, electroconvulsive therapy (ECT) is an effective treatment for about 60 percent to 80 percent of depressed patients who receive it. ECT is often used in patients who have psychotic features, display active suicidal tendencies and do not respond to antidepressant chemotherapy. The reason why ECT is effective remains unclear, but the therapy is typically associated with a slowing in the prefrontal cortex, which likely affects a fundamental neurobiologic process. ECT is usually given in courses of 6 to 12 treatments, with improvements usually occurring after the fourth treatment.
Phototherapy, or light therapy, is particularly used for fall/winter seasonal depressions. Treatment, typically prescribed for mild to moderate cases, consists of exposure to full-sprectrum white light for at least 30 minutes per day throughout the episode.
Another treatment used for mild to moderate major depression is psychological treatment. This type of intervention, including interpersonal and cognitive behavioral therapies, has been found to be as effective as antidepressant therapy. The treatment can be administered individually or in a group setting and usually lasts for 8 to 16 weekly sessions.
Combined treatments, for example anti-depressants with psychological treatment, are also used. The decision of which treatment to use should be based on patient preference, advice from a clinician, cost, practicality and success rates of different treatment types within an individual patient.
Canadian Medical Journal November 26, 2002