Editing Major depressive disorder (section)

===Environmental===
[[Adverse childhood experiences]] (incorporating [[Child abuse|childhood abuse]], neglect and [[Dysfunctional family|family dysfunction]]) markedly increase the risk of major depression, especially if more than one type.<ref name="e625">{{cite book | last1=Luyten | first1=Patrick | last2=Fonagy | first2=Peter | title=Etiopathogenic Theories and Models in Depression | chapter=An Integrative Developmental Psychopathology Approach to Depression | publisher=Springer International Publishing | publication-place=Cham | date=2021 | isbn=978-3-030-77328-1 | doi=10.1007/978-3-030-77329-8_13 | pages=245–263}}</ref> Childhood trauma also correlates with severity of depression, poor responsiveness to treatment and length of illness.<ref name="r126">{{cite journal | last1=Lippard | first1=Elizabeth T.C. | last2=Nemeroff | first2=Charles B. | title=The Devastating Clinical Consequences of Child Abuse and Neglect: Increased Disease Vulnerability and Poor Treatment Response in Mood Disorders | journal=American Journal of Psychiatry | volume=177 | issue=1 | date=1 January 2020 | issn=0002-953X | pmid=31537091 | pmc=6939135 | doi=10.1176/appi.ajp.2019.19010020 | doi-access=free | pages=20–36 }}</ref> Some are more susceptible than others to developing mental illness such as depression after trauma, and various genes have been suggested to control susceptibility.<ref name="n391">{{cite journal | last1=Li | first1=Muzi | last2=Liu | first2=Sibei | last3=D'Arcy | first3=Carl | last4=Gao | first4=Tingting | last5=Meng | first5=Xiangfei | title=Interactions of childhood maltreatment and genetic variations in adult depression: A systematic review | journal=Journal of Affective Disorders | volume=276 | date=2020 | doi=10.1016/j.jad.2020.06.055 | doi-access=free | pages=119–136 | pmid=32697690 | url=http://escholarship.mcgill.ca/downloads/dr26z282p | access-date=21 March 2025}}</ref>  Couples in unhappy marriages have a higher risk of developing clinical depression.<ref>{{cite journal |vauthors= Goldfarb MR, Trudel G |date= 6 May 2019|title= Marital quality and depression: a review |journal= Marriage & Family Review |publisher= Routledge: Taylor & Francis Group|volume= 55 |issue= 8 |pages= 737–763 |doi= 10.1080/01494929.2019.1610136 |s2cid= 165116052}} Citing among others: {{cite journal |vauthors=Weissman MM |title=Advances in psychiatric epidemiology: rates and risks for major depression |journal=Am J Public Health |volume=77 |issue=4 |pages=445–51 |date=April 1987 |pmid=3826462 |pmc=1646931 |doi=10.2105/ajph.77.4.445 }}</ref>

There appears to be a link between [[air pollution]] and depression and suicide. There may be an association between long-term [[PM2.5]] exposure and depression, and a possible association between short-term [[PM10]] exposure and suicide.<ref name="pmid31850801">{{cite journal | vauthors = Braithwaite I, Zhang S, Kirkbride JB, Osborn DP, Hayes JF | title = Air Pollution (Particulate Matter) Exposure and Associations with Depression, Anxiety, Bipolar, Psychosis and Suicide Risk: A Systematic Review and Meta-Analysis | journal = Environmental Health Perspectives | volume = 127 | issue = 12 | page = 126002 | date = December 2019 | pmid = 31850801 | pmc = 6957283 | doi = 10.1289/EHP4595 | bibcode = 2019EnvHP.127l6002B }}</ref>

Living alone has been found to increase the risk of depression by 42%.<ref name="PMH">{{cite journal |doi= 10.3389/fpsyt.2022.954857 |doi-access= free |pmid= 36111305 |pmc= 9468273 |title= Assessment of the relationship between living alone and the risk of depression based on longitudinal studies: A systematic review and meta-analysis |date= 2022 |last1= Wu |first1= Daolin |last2= Liu |first2= Fuwei |last3= Huang |first3= Shan |journal= Frontiers in Psychiatry |volume= 13 }}</ref>