Currently there are opposing theories regarding the association between poverty and mental illness. Social selection theory suggests that people who are genetically prone to mental illness drift downward into poverty, an environment that, in turn, increases their risk for mental illness. Social causation theory, on the other hand, suggests that people who are genetically prone to mental illness are more likely to experience symptoms of mental illness if they are exposed to any significant stressors, including poverty. Both theories link genetics and environment, however social selection argues that your genetic make up determines the environment in which you live. Social causation argues that your environment, particularly if stressful, will determine which genetic traits you display.

Considerable research has been conducted in an effort to settle this argument. So far, however, no studies have examined what effect moving out of poverty has on mental health. Recently, a group of researchers who were conducting a study on psychiatric disorders and the need for mental health services among rural and urban youth took the opportunity to explore this question.

Halfway through their original study, a casino opened on a nearby Indian reservation that provided every American Indian a biannual income supplement that increased annually, which changed the income level of a large percentage of the study’s participants. This provided the researchers with a natural opportunity to observe the effect this change in economic status had on the participants’ mental health.

The results of this study were published in the October 15, 2003 issue of the Journal of the American Medical Association. The researchers found that moving out of poverty significantly decreased the number of symptoms of mental illness observed among children with behavioral or oppositional defiant disorders (a pattern of uncooperative, defiant, and hostile behavior toward authority figures that seriously interferes with the child’s day to day functioning). This effect was not seen among children with emotional disorders such as anxiety or depression .

About the study

The researchers enrolled 1420 rural children between the ages of nine and 13 and followed them for a period of eight years. Among these children, 25% came from American Indian families, while the remaining were from predominantly white families.

Each family was interviewed once a year. During these interviews, each child participating in the study was assessed for symptoms of mental illness and an adult from the household was interviewed regarding the family’s level of income. The families were classified into three groups: the persistently poor (those below the federal poverty line both before and after the casino opened, the ex-poor (those whose families moved out of poverty after the casino opened), and the never poor (those whose families were above the poverty line both before and after the casino’s opening). The increase in income generated by the opening of the casino moved 14% of the families in the study out of poverty, while 53% of the families remained poor, and 32% were never poor.

The findings

The researchers found that prior to the opening of the casino, children in the persistently poor and ex-poor groups experienced more psychiatric symptoms than children who had never been poor. After the opening, certain psychiatric symptoms among the children who were no longer poor decreased to a level equivalent with that of children who had never been poor, while these psychiatric symptoms among those children who remained poor after the opening were unchanged.

This effect was noticed only among those children who displayed symptoms of behavioral and oppositional disorders, but not among children who displayed symptoms of emotional disorders, such as depression or anxiety.

How does this affect you?

The study concluded that the increase in income that moved 14% of the American Indian families in the study out of poverty had a major effect on certain types of psychiatric disorders. These results support a social causation theory for behavioral and oppositional disorders among children. In other words, poverty comes first.

After further analysis, the researchers also found evidence to suggest that the primary reason for the decrease in symptoms of mental illness among these children was due to improved parental supervision. There appeared to be two reasons for this. First, the number of single parent homes decreased. Second, among two-parent homes, there were more homes in which both parents were working. This resulted in decreased time-demands on the primary caregiver.

An editorial published in the same issue of the journal stated that the findings of this study go a long way towards demonstrating the reality of the social causation theory. This would suggest that programs designed to treat behavior disorders in poor children must be linked with programs that first and foremost address their underlying poverty.