The World Health Organization identified mood disorders as a significant public health problem more than a decade ago. Some evidence suggests that the incidence of mood disorders is increasing. The lifetime prevalence rate for all mood disorders is about 8.3%; for serious depression, 5.8%; for bipolar disorder, 0.8%; and for chronic dysthymia, 1.7%. These figures are based on both American and Canadian studies (Table 1). Mood disorders frequently begin in early adulthood and can last an entire lifetime. Women are affected about twice as often as men.
| Table 1. Lifetime prevalence of psychiatric disorders | |
|
TYPE OF DISORDER |
RANGE (%) |
| Any disorder |
28.8-38.8 |
| Substance abuse |
18.0-20.6 |
| Anxiety disorders |
10.4-28.1 |
| Affective disorders |
6.1-10.2 |
| • Manic episode |
0.6-1.1 |
| • Serious depressive episode |
3.7-8.6 |
| • Dysthymia |
2.1-3.8 |
| Schizophrenia |
0.6-1.9 |
| Adapted with permission from Bland. | |
The mortality and morbidity associated with depression are significant. About 15% of individuals with untreated depression commit suicide; about 80% of those who attempt suicide are suffering from a mood disorder. Many deaths noted as motor vehicle or industrial accidents are, in fact, acts of suicide. The morbidity associated with mood disorders is expressed as unemployment, underachievement, low productivity, being accident-prone, family discord, substance abuse, and chronic misery. A recent study determined that the disability associated with a chronic mood disorder was equal to, or greater than, any of eight major disease categories that include diabetes, hypertension, and arthritis.
Psychiatric services have increased over the past decade; the biological basis for depression is more clearly understood; and improved and more specific treatment is now available. Yet surveys reveal that only about one third of individuals suffering from a mood disorder receive treatment. Twenty-five percent of patients receive inappropriate treatment and, of those prescribed an antidepressant, about a third receive an inadequate dose, even if they have been admitted to a tertiary care centre. Only about 25% of patients with a mood disorder actually see a psychiatrist. The remainder are treated by a family physician (71%) or other professional person.
In the face of these rather alarming figures, the National Institute of Mental Health launched a campaign in 1988 to educate both practitioners and the general public about mood disorders. The figures highlight the need for family physicians to assess mood disorders properly and to provide adequate treatment. This article focuses on the assessment and treatment of treatment-resistant depression (TRD).