Impact of urban living on mental health

By 2050, two-thirds of the world’s population will live in cities. Urban life is characterized by high density of commercial and residential buildings, more stressful environments, reduced access to green spaces, increased exposure to drug use, and more.

A recent study published in natural medicine I am investigating the effects of the urban environment on the mental health of adults.

study: Effects of Urban Living Environment on Mental Health of Adults. Image credit: Alexander Ozerov /Shutterstock.com

research result

In this study, researchers investigated the effects of the urban environment on the mental health of adults aged 41 to 77 from the United Kingdom Biobank (UKB). The study included 156,075 participants, mostly from urban areas. Participants were stratified based on the availability of neuroimaging (NI) data.

Brain NI was performed on over 42,000 subjects, of whom 14,988 had complete NI, while the remaining 141,087 participants constituted the non-NI dataset. A total of 128 urban environmental variables and 21 psychotic symptoms across 53 categories were assessed. Sparse canonical correlations were performed to determine associations between urban life categories and psychiatric symptoms.

A split data analysis was implemented on the training and test datasets comprising 90% and 10% of the data, respectively, from the non-NI dataset. The urban environmental profile was significantly associated with his five psychiatric affective symptoms in the training dataset and was also reproduced in the test dataset.

The affective symptom group included frequencies such as fatigue, apathy, depressed mood, boredom, and loneliness. Moreover, these symptoms were positively correlated with noise and air pollution, urban infrastructure density and traffic, measures of road network accessibility, and socioeconomic indicators of multiple poverty.

The affective symptom group was negatively correlated with proximity to green spaces and distance to urban facilities. The research team identified another symptom set (Anxiety Symptom Group) that included anxious feelings, nervousness, excessive worry, nervous distress, psychiatric visits, and nervous feelings.

Anxiety symptom clusters were significantly associated with a secondary urban environment profile that was positively correlated with variations in mixed urban infrastructure and leisure site density, proximity to coast, average topography, and normalized differential vegetation index (NDVI). was By comparison, anxiety symptoms were negatively correlated with proximity to water, distance to energy and waste facilities, and mean NDVI.

A third set of symptoms, which fall under the emotionally unstable symptom group, included mood swings, frequency of miserable moods and extreme moods, neurotic scores, irritability and irritability, risk-taking, stress, sadness, It consisted of hurt feelings. These symptoms were negatively correlated with distance to grocery stores, water density, unused land, comfort amenities, and open space.

The emotionally unstable group was positively correlated with changes in terrain and the density of educational, accommodation, medical and emergency facilities. These correlations were repeated by applying split data analysis of the NI dataset, reproducing the three significant correlations identified in the primary analysis.

A standard covariate genome-wide association study of the three symptom sets was conducted in a subset of non-NI participants using the complete urban environment, psychiatric, and genomic data. A gene set enrichment analysis was performed to identify underlying genes associated with the symptom set.

More than 3,400 significant associations with single nucleotide polymorphisms (SNPs) have been reported in genes for affective symptoms. The strongest association was with a candidate supergene SNP on chromosome 17q21.3 and corticotropin-releasing hormone receptor 1 (CRHR1)gene.

The anxiety symptom group was significantly associated with 29 SNPs across 9 genes, rs77641763 being associated with 3 (EXD3)gene. The emotional lability symptom group was significantly associated with 10 SNPs, the lead SNP of rs77786116 being present in intraflagellar trafficking 74 (IFT74)gene.

Multiple sparse canonical correlations on urban environment profiles, psychosis sets, and brain volumes were performed on independent NI datasets. Significant associations were evident between 13 regions of brain volume, affective symptom groups, and initial environmental profiles. Eleven regional brain volumes were associated with the anxiety symptom group and his secondary urban environmental profile.

Similarly, 12 brain volumes were associated with a third urban environmental profile and emotional lability symptom group.

A moderation-mediated analysis was also performed to assess whether genetic differences moderate the association mediated by brain volume. to this end, CRHR1, EXD3and IFT74 Genetic scores moderated mediation pathways in the Affective, Anxiety, and Emotional Instability groups, respectively.

Conclusion

Certain urban environmental profiles correlated with different symptom groups. The first urban profile associated with affective symptoms was characterized by air pollution, poverty, traffic, lack of green space, and short distances to urban facilities, reflecting dense, poor inner-city neighborhoods.

A second urban profile was inversely associated with anxiety symptoms and was characterized by long distances to green spaces, lakes, rivers, oceans, and energy and waste facilities. The third city profile is associated with symptoms of emotional lability and explains a smaller variance than his first two symptom groups. This profile was positively correlated with urban infrastructure and land-use density.

Taken together, the research results suggest that different urban environmental profiles can affect specific mental health symptoms.