The United Nations predicted in 2018 that 68 percent of the world’s population would live in urban areas by 2050, up from 55 percent in the present. This is a cause for concern among researchers because urban living is associated with a number of risk factors for mental illness.
One 2019 meta-analysis compared depression rates in the developed and developing worlds among older adults, and another from 2010 found that the prevalence of mood disorders was higher in urban areas.
Researchers from the Department of Psychology at the University of Pennsylvania have now conducted the first meta-analysis examining the global relationship, in developed and developing countries, between urban living and the prevalence of depression across all ages. They found that urbanicity is associated with higher rates of depression in developed but not developing countries.
Depression Demographics
The meta-analysis found “there was a significant effect of urbanicity on depression” in developed countries, such as the United States, the United Kingdom, Canada, Sweden, France, and Japan. The probabilities of depression were 1.37 times higher in the city than in the country.
Colin Xu, the first author and a former Ph.D. student in the lab of Penn psychology professor Robert DeRubeis, focused his dissertation on statistical modelling to predict depression outcomes. He has since joined the psychology faculty at the University of Idaho as an assistant professor.
DeRubeis, the paper’s senior author, says he has been researching depression for more than 40 years but has never investigated these kinds of demographic influences.
The authors found “no significant effect of urbanicity on depression” in developing countries such as China, India, Taiwan, South Korea, and Nigeria. They sorted countries into developing or developed countries based on the UN’s World Economic Situation and Prospects 2022 report categories.
Breeder Hypothesis vs Drift Hypothesis
According to Xu, one possible explanation is that people with depression do not travel to cities for treatment due to a lack of services in both cities and rural areas. DeRubeis further noted that because these are developing countries, urban elements associated with depression in affluent countries may not be as prominent as they are in developing ones.
Seeing the results in developed countries, one might ask if living in a city makes people more depressed or if people with depression are more likely to move to or stay in cities. These concepts are respectively called the breeder hypothesis and drift hypothesis.
As for the breeder hypothesis,
urban living is associated with social disparities, economic insecurity, pollution, and a lack of contact with nature, all of which can adversely affect mental health,”
the paper notes. However, DeRubeis points out that if other aspects of urban life are studied, they may be linked to decreased incidence of depression.
According to the paper, the drift hypothesis states that people with depression may move from rural to urban areas due to increased access to psychological treatment or reduced stigma.
“I don’t know of any research on that vis-à-vis depression, so you’ve got an absence of evidence, which is different from the evidence of absence, and then you have positive evidence on the other side,”
DeRubeis said.
“More research is needed to disentangle whether the drift or breeder effect — or both together — are driving the differences in depression prevalence between urban and rural areas,”
the authors write. According to Xu, the evidence is not strong enough to rule out one completely, but both factors appear to contribute to the observed effect.
Age Group Differences
The research states that the influence of urbanicity on depression in industrialized countries appears to be driven mostly by the general population demography, whereas no significant relationship was found between urbanicity and depression in older people or children/adolescents. In undeveloped countries, urbanization had no substantial influence on any of these three age groups.
“The earlier studies show that in developing countries living in rural areas has more depression than living in urban areas, but more recent studies show the pattern that developed countries have always shown,”
Xu said.
“If this finding is not spurious, it suggests that the risks of modern living that have contributed to the greater urban depression in developed countries may be gradually beginning to impact developing countries as these countries modernize,”
the paper concluded.
Abstract
Background: Previous meta-analyses have revealed that in adult and older adult populations of developed countries, depression is more prevalent in urban than rural areas. No meta-analyses have identified the effects of urbanicity on the general age demographic for developing countries. We conducted a meta-analysis of urban-rural differences in depression across all age demographics for developed and developing countries.
Methods: PubMed and PsycINFO databases were searched for studies published between 1980 and 2020. Studies were included if they reported prevalences of urban and rural depression, or odds ratios comparing urban-rural depression prevalence. Studies were excluded for: nonrepresentative samples, non-standard measures of depression, and reporting continuous outcomes only. Meta-analytic models of urban-rural differences in the odds of depression were conducted across country development levels and age demographics.
Results: From 1597 records screened and 302 full texts assessed for eligibility, 80 studies (N = 539,557) were included for meta-analysis. Urban residence was significantly associated with a higher prevalence of depression in developed countries (OR = 1.30, 95 % CI [1.17, 1.46], z = 4.75, p < .001), which was primarily driven by urban-rural differences in the general population age demographic (OR = 1.37, 95 % CI [1.22, 1.54], z = 5.38, p < .001).
Limitations: Studies reporting urban-rural differences in depression in terms of continuous symptom severity scores were not included.
Conclusions: Urbanicity appears to uniquely be associated with a higher prevalence of depression in developed countries, but not in developing countries.
Reference:
- Colin Xu et al. Urbanicity and depression: A global meta-analysis. Journal of Affective Disorders (2023). DOI: 10.1016/j.jad.2023.08.030
Last Updated on November 11, 2023