Relationships between poverty and psychopathology: a natural experiment.
BACKGROUND
Social causation (adversity and stress) vs social selection (downward mobility from familial liability to mental illness) are competing theories about the origins of mental illness.


OBJECTIVE
To test the role of social selection vs social causation of childhood psychopathology using a natural experiment.


METHODS
Quasi-experimental, longitudinal study.


METHODS
A representative population sample of 1420 rural children aged 9 to 13 years at intake were given annual psychiatric assessments for 8 years (1993-2000). One quarter of the sample were American Indian, and the remaining were predominantly white. Halfway through the study, a casino opening on the Indian reservation gave every American Indian an income supplement that increased annually. This increase moved 14% of study families out of poverty, while 53% remained poor, and 32% were never poor. Incomes of non-Indian families were unaffected.


METHODS
Levels of Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, psychiatric symptoms in the never-poor, persistently poor, and ex-poor children were compared for the 4 years before and after the casino opened.


RESULTS
Before the casino opened, the persistently poor and ex-poor children had more psychiatric symptoms (4.38 and 4.28, respectively) than the never-poor children (2.75), but after the opening levels among the ex-poor fell to those of the never-poor children, while levels among those who were persistently poor remained high (odds ratio, 1.50; 95% confidence interval, 1.08-2.09; and odds ratio, 0.91; 95% confidence interval, 0.77-1.07, respectively). The effect was specific to symptoms of conduct and oppositional defiant disorders. Anxiety and depression symptoms were unaffected. Similar results were found in non-Indian children whose families moved out of poverty during the same period.


CONCLUSIONS
An income intervention that moved families out of poverty for reasons that cannot be ascribed to family characteristics had a major effect on some types of children's psychiatric disorders, but not on others. Results support a social causation explanation for conduct and oppositional disorder, but not for anxiety or depression.
Costello
E Jane
EJ
Developmental Epidemiology Program, Department of Psychiatry and Behavioral Sciences, Duke University Medical School, Durham, NC 27710, USA. jcostell@psych.mc.duke.edu
Compton
Scott N
SN
Keeler
Gordon
G
Angold
Adrian
A
D000293:Adolescent; D001741:Black or African American; D001007:Anxiety; D002648:Child; D002653:Child Behavior Disorders / Q000453:epidemiology; D019955:Conduct Disorder / Q000453:epidemiology; D003863:Depression / Q000453:epidemiology; D006801:Humans; D007198:Indians, North American; D008137:Longitudinal Studies; D001523:Mental Disorders / Q000453:epidemiology*; D009657:North Carolina / Q000453:epidemiology; D011203:Poverty; D011599:Psychopathology; D012424:Rural Population; D012959:Socioeconomic Factors; D013315:Stress, Psychological; D044465:White People