The Effect of Maternal Depression and Substance Abuse on Child Human Capital Development

Depression has been shown to affect the functioning, educational attainment and work-related outcomes of adults affected by the disease. Clinical evidence links maternal depression and behavior problems in children. Little research attention has been accorded the inter-generational effects of parental mental and addictive disorders on cognitive, behavioral, and educational outcomes of children. Heckman (2007) has shown that social and emotional aspects of early childhood outcomes have profound effects on the ultimate economic well-being of individuals. We study effects of maternal depression and substance abuse among children born to mothers in the initial cohort of the 1979 National Longitudinal Survey of Youth (NLSY), a national household survey of high school students aged 14-19 in 1979. We follow 1587 children aged 1-5 in 1987, observing them throughout childhood and into high school. To identify the intergenerational impact of maternal depression and substance abuse on child outcomes in primary and secondary school, we use employ propensity score methods to control for a rich set of early life factors of the mother. Specifically, we use information on the mental health status and alcoholism of maternal grandparents and the presence of symptoms of mental and addictive disorders early in a mother’s life, and early depression and alcohol abuse symptoms in a mother’s sibling to predict symptoms of maternal depression in models of child outcomes described above. We also estimate fixed effect models, to examine within mother differences in symptoms of depression and substance abuse on different siblings, with similar results. After controlling for early life predictors of maternal depression, maternal symptoms of depression have little effect on contemporaneous cognitive scores in children. However, maternal depression symptoms have a moderately large effect on child behavioral problems. The pattern of results is similar for maternal symptoms of alcohol abuse. These findings suggest that the social benefits of effective behavioral health interventions are understated. Based on evidence linking early life outcomes to later well-being, efforts to prevent and/or treat mental and addictive disorders in mothers and other women of childbearing age have the potential to improve outcomes of their children not only early in life, but throughout the life cycle. We gratefully acknowledge funding from the National Institute of Drug Abuse and the MacArthur Network on Mental Health Policy. We thank Kathleen Reilly for excellent programming assistance. Draft– Preliminary. Please do not cite or circulate. 2 Introduction New approaches to modeling the formation of human capital represents a synthesis of the human capital approach and a life cycle view of human development that is grounded in neuroscience(Heckman 2007). That literature highlights the importance of the household environment on the development of children and the fact that a child’s relationship with their care giver is important in determining the development of the brain. Thus, the stability of the home and parental mental health can have notable impacts on skill development in children that may have impacts on the stock of human capital in adults (Knudsen, Heckman et al. 2006; Heckman 2007). There is a well developed literature that links mental illness in adults to lower levels of employment, reduced productivity, lower earnings and early exits from the labor force (Currie and Madrian 1999; Frank and Koss 2005). Empirical analysis of the causal links between mental illness and labor market outcomes reveal evidence of intergenerational effects of mental disorders on labor market outcomes. That is, working age adults with parents that suffered from mental disorders had relative odds of working that 5 to 10 percent lower than the odds for otherwise similar adults that reported no mental illness in their parents (Ettner, Frank et al. 1997). Similarly parental mental illness has the effect of reducing earnings and hours worked in working adults holding constant other factors affecting labor supply. That research and other work (Currie and Stabile 2008) also suggest that the effect is in part due to an increased likelihood of experiencing a mental illness if one’s parents had such illnesses (relative odds of 1.12 to 1.24). Understanding how parental mental disorders can affect skill accumulation and adult 1 When we refer to mental illnesses we include substance use and abuse disorders. Draft– Preliminary. Please do not cite or circulate. 3 human capital is especially important given that there are cost-effective treatments that have been tested in women of child bearing ages at various income levels (U.S. Department of Health and Human Services 1999; Miranda, Chung et al. 2003). Thus, ameliorating parental mental health problems offer the potential to efficiently bolster the development of human capital at an early age. In this paper we examine the impact of maternal depression and substance abuse on the cognitive and behavioral development of children during their early school years. We make use of data from the National Longitudinal Survey of Youth, 1979 cohort, to estimate the impact of maternal mental health on a set of cognitive and behavioral outcomes in grammar school aged children. Our results show that the main effect of maternal mental health problems is on behavioral rather than cognitive outcomes. As shown in recent work(National Research Council and Institute of Medicine 2000; Heckman 2006; Cunha and Heckman 2007; Heckman 2007), non-cognitive skills and attributes are important determinants of economic success that have been under appreciated in policy circles. The paper is organized into 7 sections. The first summarizes background research on child development and maternal depression. The second provides a theoretical discussion of how maternal depression and substance use and abuse may influence child human capital development. Section 3 describes our data and measures of interest. Section 4 lays out the empirical strategy in detail. Section 5 provides the main results on how maternal behavioral health influences maternal investments in children and child outcomes. Section 6 provides alternative specifications of these results and robustness checks. Section 7 concludes with a discussion of implications. Draft– Preliminary. Please do not cite or circulate. 4 Background Research in neurobiology and child development shows important effects that stress in the home environment can have for the healthy development of children. That research also shows that early influences (positive or negative) on emotional development in children can have lasting effects into adulthood. The quality of maternal care early in life is known to be important in animals and humans (McEwan and Seeman 1999). Stable and supportive care giving environments have been linked to an enhanced ability to cope with stress that reduces the likelihood of mental health problems. Maternal depression is thought to disrupt the care giving environment (U.S. Department of Health and Human Services 1999; Kim-Cohen, Moffit et al. 2005). The early literature on maternal depression established evidence that there are important and lasting effects of maternal depression on child development (Cogill, Caplan et al. 1986). A study by Cogill and colleagues (1986) shows that maternal depression early in a child’s life (1 year) has a negative and significant effect of cognitive skills measured at age 4. A meta-analysis published in 1999 reviewed 33 studies of the relationship between maternal depression and child behavior (Beck 1999). That review showed a consistent relationship between maternal depression and child behavior. The results showed that behavior problems occurred both in the pre-school period and among school aged children. Two more recent studies have been reported. In one paper, (Petterson and Albers 2001), the authors analyzed the National Maternal and Infant follow back survey data to examine the impacts of maternal depression and poverty on child development. They found that mothers with likely depression as measured by a CESD score of 16 to 30 and Draft– Preliminary. Please do not cite or circulate. 5 30 and above had young children that scored lower on cognitive and motor skills development tests. They also found that higher income levels appear to attenuate but do not eliminate the effects of maternal depression. A British study examined the link between maternal depression and antisocial behavior in children (Kim-Cohen, Moffit et al. 2005). Using data on twins, the authors examined the impact of maternal depression that occurred during the first 5 years of life on antisocial behavior measured at age 7. They also examined the incremental effects of maternal depression that occurred when the children were aged 5 to 7 years. The results showed a significant impact on antisocial behavior at age 7 of both early maternal depression and more recent depression. The presence of mental health problems in school aged children has been linked to long term reduction in the accumulation of human capital (Currie and Stabile 2008). Currie and Stabile (2008) use the National Longitudinal Survey of Youth (NLSY) to examine the impact of mental disorders on children and their subsequent academic achievement. They show that ADHD and conduct disorders both have negative and significant impacts on achievement test scores and levels of educational attainment. Together these results suggest that maternal depression, one of the most treatable of mental disorders, can have lasting effects on the accumulation of human capital early in