Prevalence and Incidence
Sociodemographic Risk Factors
Gender
Age
Marital Status
Social Economic Status
Life Events
Stigma and Discrimination
Comorbidity
Psychiatric Comorbidity
Physical Comorbidity
Physical Activity
Course of Major Depression
Child and Adolescent Studies
Societal Cost
Global Burden of Disease
Treatment Gap
Conclusion
References
Prevalence and Incidence
In DSM-5 (American Psychiatric Association 2013) major depressive disorder is defined as having five or more symptoms during the same two-week period, which cause clinically significant distress or impairment, and at least one should be a depressed mood or loss of interest or pleasure. The other symptoms include: change in weight; sleep disturbance; psychomotor agitation or retardation; fatigue or loss of energy; worthlessness or guilt; impaired concentration; and thoughts of death. The current DSM-5 criteria are similar to the DSM-IV (American Psychiatric Association 2000) diagnostic criteria used in most of the psychiatric epidemiological surveys conducted since the 1990s.
The anxiety disorders have been redefined from DSM-IV to DSM-5. In DSM-IV the anxiety disorders included panic disorder, agoraphobia without a history of panic disorder, specific phobia, social phobia, post-traumatic stress disorder, acute stress disorder, generalized anxiety disorder, and obsessive-compulsive disorder. The anxiety disorders in DSM-5 have been narrowed with post-traumatic stress disorder and acute stress disorder being moved into a category entitled Trauma – and Stressor- Related Disorders and obsessive-compulsive disorder being placed in a category entitled Obsessive-Compulsive and Related Disorders. Current psychiatric epidemiological studies are primarily based on the DSM-IV definition of anxiety disorders. Acute stress disorder is not usually included among general population psychiatric epidemiological surveys and the inclusion of obsessive-compulsive disorder may be variable.
Prevalence and incidence studies are based on representative community household surveys that utilize a structured diagnostic instrument, such as the Composite International Diagnostic Interview (CIDI) (Robins et al. 1988). The prevalence of major depressive disorder varies widely cross nationally. For example, the 12-month prevalence ranges from 0.3% in Vietnam to 10.2% in Iran. Across studies based on DSM-IV using the CIDI the estimated median 12-month prevalence is 4.7% (n = 42 studies) (see Table 1.1). Similarly, there is a broad range of lifetime prevalence rates from 3.2% in Nigeria to 20.4% in France. The median lifetime prevalence is estimated at 9.9% (n = 39 studies). Major depressive disorder has an early age of onset; the median age in epidemiological studies is approximately 27.6 years of age (n = 23 studies).
Table 1.1Twelve-month and lifetime DSM-III-R and DSM-IV prevalence rates and age of onset of major depressive episodes and anxiety disorders from selected Composite International Diagnostic Interview studies
Country | Major Depression | Anxiety Disorders |
12M | LT | Onset | 12M | LT | DX |
Australia | 4.8 | 12.8 | | 11.8 | 20.0 | 1–5,7 |
Belgium | 5.2 | 14.1 | 29.4 | 8.4 | 13.1 | 1,2,4,5,7,8 |
São Paulo, Brazil | 10.1 | 18.0 | 24.3 | 19.9 | 28.1 | 1–8 |
Bulgaria | 3.0 | 6.7 | | 5.6 | | 1,2,4,7,8 |
Beijing and Shanghai, China | 2.0 | 3.8 | 30.3 | 3.0 | 4.8 | 1,2,4,5,7,8 |
Shenzhen, China | 3.6 | 6.8 | 18.8 | | | |
Canada | 4.8 | 12.2 | | 4.7 | | 1,4,7 |
Chile* | 5.7 | 9.2 | | 9.9 | 16.2 | 1,2,4,5,7,8 |
Colombia | 5.3 | 11.8 | 23.5 | 14.4 | 25.3 | 1,2,4,5,7,8 |
Medellin, Colombia | 3.8 | 9.9 | | | | |
Czech Republic* | 2.0 | 7.8 | | | | |
Finland | 7.4 | | | | | |
France | 5.6 | 20.4 | 28.4 | 13.7 | 22.3 | 1,2,4,5,7,8 |
Germany | 3.1 | 10.3 | 27.6 | 8.3 | 14.6 | 1,2,4,5,7,8 |
Guatemala | 0.8 | 3.2 | | 2.3 | 5.2 | 1–5,7 |
Pondicherry, India | 4.5 | 9.0 | 31.9 | | | |
Iran | 10.2 | | | 15.6 | | 1–5,7 |
Iraq | 3.9 | 7.2 | 46.0 | 10.4 | 13.8 | 1,2,4,5,7,8 |
Israel | 5.9 | 9.8 | 25.5 | 3.6 | 5.2 | 1,2,4,5,7,8 |
Italy | 2.9 | 9.7 | 27.7 | 6.5 | 11.0 | 1,2,4,5,7,8 |
Japan | 2.4 | 6.8 | 30.1 | 4.2 | 6.9 | 1,2,4,5,7,8 |
Lebanon | 4.9 | 10.3 | 23.8 | 12.2 | 16.7 | 1,2,4,5,7,8 |
Mexico | 3.7 | 7.6 | 23.5 | 8.4 | 14.3 | 1,2,4,5,7,8 |
Netherlands | 4.9 | 18.0 | 27.2 | 8.9 | 15.93 | 1,2,4,5,7,8 |
New Zealand | 5.7 | 15.8 | 24.2 | 15.0 | 24.6 | 1,2,4,5,7,8 |
Nigeria | 1.1 | 3.2 | 29.2 | 4.2 | 6.5 | 1,2,4,5,7,8 |
Northern Ireland | 8.8 | 17.7 | | 12.3 | | 1,2,4,7,8 |
Norway* | 7.3 | 17.8 | | | | |
Peru | 2.7 | 6.4 | 38.0 | 7.9 | 14.9 | 1,2,4,5,7,8 |
Poland | 1.6 | 3.8 | | | | |
Portugal | 7.0 | 17.4 | | 13.7 | | 1,2,4,7,8 |
Romania | 1.5 | 2.9 | | 4.2 | | 1,2,4,7,8 |
Singapore | 2.2 | 5.8 | 26.0 | 0.4 | 0.9 | 2 |
South Africa | 4.9 | 10.4 | 22.3 | 8.2 | 15.8 | 1,2,4,5,7,8 |
South Korea | 3.1 | 6.7 | | 6.8 | 8.7 | 1,2,4,5,7,8 |
Spain | 3.8 | 10.6 | 30.0 | 6.6 | 9.9 | 1,2,4,5,7,8 |
Murcia, Spain | 6.0 | 13.8 | | 9.7 | 15.0 | 1–8 |
Bangkok, Thailand | | 19.9 | | | 10.2 | 9 |
Turkey* | 3.5 | 6.3 | | 5.8 | 7.4 | 1,2,4,7,8 |
Izmir, Turkey | 8.2 | | | | | |
United States | 8.3 | 19.2 | 22.7 | 19.0 | 31.0 | 1,2,4,5,7,8 |
Ukraine | 8.4 | 14.6 | 27.8 | 6.8 | 10.9 | 1,2,4,5,7,8 |
Mekong Delta, Vietnam | 0.3 | | | 0.4 | | 1–5,7 |
Data on the one-year incidence of major depression is based on a small number of prospective studies. The Epidemiological Catchment Area (ECA) survey reported an incidence rate of 1.6 per 100 person years at risk, 2.0 females and 1.1 males (Eaton et al. 1989). The Baltimore site of the ECA, 1981–1993, had an incidence rate of 0.3 (Eaton, Kalaydjian, Scharfstein, Mezuk, & Ding 2007). During the 1993–2004 period the incidence rate was 0.2. However, the difference between the two time periods, and incidence rates also found in shorter follow-up studies, may be due to attrition in the sample and not that the incidence of major depression is declining. For both periods, female gender and age of 30–44 had the highest incidence rates. A study based in Edmonton, Canada had an incidence rate of 2.8, with a rate for females of 3.7 and males 2.0 (Newman & Bland 1998). The incidence rate in the Canadian study was highest for age 45–64. The Netherlands Mental Health Survey and Incidence Study (NEMESIS) reported an incidence rate of 2.7 for major depression, 3.9 females and 1.7 males. The incidence rate was highest for males for ages 25–34 and for females for age 35–44 (Bijl, de Graaf, Ravelli, Smit, & Vollebergh 2002). The NEMISIS study examined risk factors associated with the incidence of a mood disorder; female gender, having a negative life event in the past 12 months, ongoing difficulties in the past 12 months, high neuroticism and sleep problems were all associated in an adjusted logistic regression model (de Graaf, Bijl, Ravelli, Smit, & Vollebergh 2002). In the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) risk factors for incidence of major depression included female gender, age 18–55, low income and being unmarried. The incidence rate for the NESARC study was 1.5, similar to the ECA study (Grant et al. 2009)....