The disease burden of childhood adversities in adults: A population-based study

Abstract

Objectives

There is much evidence showing that childhood adversities have considerable effects on the mental and physical health of adults. It could be assumed therefore, that the disease burden of childhood adversities is high. It has not yet been examined, however, whether this is true.

Method

We used data of a large representative sample (N = 7,076) of the general population in the Netherlands. We calculated the disability weight (DW) for each respondent. The DW is a weight factor that reflects the severity of a disease or condition on a scale from 0 (perfect health) to 1 (equivalent to death). We used an algorithm based on the SF-6D to estimate DW. Because the DW indicates the proportion of a healthy life year that is reduced by the specific health state of the individual, it also possible to calculate the total number of years lost due to disability (YLD) in the population. We calculated the years lived with disability (YLD) for 9 different childhood adversities (in the areas of parental psychopathology; abuse and neglect; major life events), as well as for major categories of mental disorders and general medical disorders.

Results

All 9 adversities resulted in a significantly increased DW, except death of a parent before the age of 16. Adversities in the category of abuse and neglect are associated with the highest DWs (0.057), followed by parental psychopathology (0.031) and life events during childhood (0.012). All adversities (46.4% of the population reports one or more adversity) are associated with 20.7 YLD/1,000, which is more than all mental disorders together (12.9 YLD/1,000). The category of abuse/neglect has the highest YLD/1,000 (15.8), which is also higher than all mental disorders together. Adjustment for the presence of mental and general medical disorders resulted in comparable outcomes.

Conclusions

Childhood adversities are more important from a public health point of view than all common mental disorders together, and should be a priority for public health interventions.

Introduction

There is much evidence showing that the long-term effects of childhood adversities on mental and physical health are considerable. The increased risk of developing a mental disorder in adults with an adversity during childhood has been confirmed in many studies, and includes an increased risk for mood disorders (Collishaw et al., 2007, Comijs et al., 2007, Kessler et al., 1997), anxiety disorders (Phillips et al., 2005, Springer et al., 2007), alcohol problems (Kessler et al., 1997, Kestilä et al., 2008), eating disorders (Johnson, Cohen, Gould, Kasen, et al., 2002), and psychotic symptoms (De Graaf et al., 2004, Janssen et al., 2004). Furthermore, childhood adversities have been found to be significantly associated with an increased risk for suicidal ideation and suicide attempts (Enns et al., 2006), with increased rates of comorbidity in mental disorders (De Graaf, Bijl, ten Have, Beekman, & Vollebergh, 2004), with severe interpersonal difficulties (Johnson, Cohen, Kasen, & Brook, 2002), weight problems (Johnson, Cohen, Gould, et al., 2002), and early retirement because of disability (Harkonmäki et al., 2007). Other evidence shows that childhood adversities may be associated with general medical disorders, such as migraine (Juang et al., 2004, Sumanen et al., 2007), peptic ulcers (Markku, Koskenvuo, Sillanmäki, & Mattila, 2009), arthritis (Scott et al., 2008, Von Korff et al., 2009), coronary heart disease (Sumanen, Koskenvuo, Sillanmäki, & Mattila, 2005), and diabetes (Thomas, Hyppönen, & Power, 2008).

Because childhood adversities seem to cut across many different disorders and problems, it may be very well possible that the quality of life in adults having one or more childhood adversities is considerably reduced. Whether or not childhood adversities are associated with an increased disease burden in adults has not been examined yet. In the current study, we will try to estimate the disease burden of childhood adversities using data from a large representative population-based study.

The relationship between childhood adversities on the one hand and health during adulthood on the other hand, can be explained using different models. Several studies show that life stress, addiction or depression could function as a direct or an indirect effect on the relationship between childhood adversities and decreased health in adulthood. For example, the experience of childhood adversities may result in coping or regulation strategies that have a negative impact on health, such as smoking, high alcohol consumption or over-eating. These might lead to health problems, which might in turn lead to disease burden (Felitti et al., 1998, Sachs-Ericsson et al., 2009, Wegman and Stetler, 2009). There are indications that abuse-related alterations in brain function are possible mediators in etiology, which may reduce immune system or increase the vulnerability to stress (Sachs-Ericsson et al., 2009).

In addition, in many cases, other family problems than parental psychopathology or child maltreatment may co-occur, further affecting both mental and general medical disorders. Family characteristics like family conflict, neglectful relationships or social emotional status could put children at risk for traumatic experiences and are often found in families where child maltreatment is prevalent (Sachs-Ericsson et al., 2009, Wegman and Stetler, 2009). This poses the question of how exactly negative health outcomes are linked to childhood adversities. A more complete understanding of these issues is likely to lead to a better understanding of the relationship between childhood adversities and disease burden.

In most research, disease burden is expressed in terms of “disability-adjusted life years” (DALY). One DALY is equivalent to one lost year of healthy life. It represents an estimation of the gap between current health status and an ideal situation of the whole population living into old age in full health. The DALY has its origins in an assessment of the Global Burden of Disease study, which was conducted under auspices of the World Bank and WHO (Murray & Lopez, 1996). The DALY combines years of life lost (YLL) due to premature mortality and years lost due to disability (YLD). If a disease results in premature death it can be calculated how many years of life are lost in a given population because of that disease. In the same way, it is possible to calculate how many years are lost in terms of quality of life, because of years lived with a certain disease. For example, it is estimated that of each year lived with a major depressive disorder, 46% of the quality of life in this year is missed because of the depressive disorder (Kruijshaar, Hoeymans, Spijker, Stouthard, & Essink-Bot, 2005). This 46% is also called the disability weight (DW). If in a population of 1,000, 50 people have a major depression during a full year, the YLD in that population is 23 (50 × 0.46). That means that of a total of 1,000 lived years, 23 years are lost because of major depression.

In the current study, we will only focus on the YLD which can be attributed to childhood adversities. There is much research showing that childhood adversities are associated with health outcomes in adulthood (Corso et al., 2008, Felitti et al., 1998, Sachs-Ericsson et al., 2007, Sachs-Ericsson et al., 2009). However, the overall impact of childhood adversities on disease burden on a population level has not been examined well.

In the current study, we will focus on non-fatal disease burden (expressed in YLD) that can be attributed to childhood adversities. We will also compare these results with the YLD that are associated with mental and general medical disorders.