Genética y Economía. El impacto del riesgo genético de padecer TDAH en los conflictos maritales que acaban en divorcio

In this contribution we intend to synthesize some of the central ideas of the research project that were presented in the competition for access to the position of Professor of the University by the professor. joan gil (February 13, 2024) and Full Professor of the University by the professor Alessio Gaggero (March 12, 2024). Veteran members of the AES community such as Guillem López Casasnovas and Ángel López Nicolás participated in the selection commission for the provision of these positions.

Public policy evaluation is a key tool for improving public sector accountability through evidence-based policy formulation. In recent years, policy evaluation has become more widespread in the Social Sciences, and particularly in the area of ​​Economics.

Randomized experiments are widely recognized as the gold standard in policy evaluation, particularly for estimating causal effects. In a randomized experiment, participants are randomly assigned to a treatment group or a control group. The randomization of assignment ensures that the treatment and control groups are statistically equivalent, allowing a direct comparison of results of a given policy or intervention between these groups. However, conducting randomized experiments is not always feasible, mainly due to ethical considerations and budgetary constraints; Therefore, in its absence, researchers have developed several innovative methods to estimate robust causal relationships. These methods generally exploit natural events that cause participants to be exposed or not to a given treatment in a quasi-random manner. Significant advances in quasi-experimental methods, together with the emergence of extraordinarily rich and detailed databases, including in many cases genetic data, have paved the way for a new field of study that merges genetics and economics (e.g. , see this post blog Nothing is free).

The objective of this research is to evaluate the consequences of one of the most common mental health disorders between 3 and 17 years of age: Attention Deficit Hyperactivity Disorder (ADHD) (Bitsko et al., 2022). According to recent data from the USA, there is a growing trend in the prevalence of this disorder, which went from 6.1% (1997) to 10.5% (2022) (Li et al., 2023). This condition is frequently diagnosed during childhood or adolescence and largely persists into adulthood. The most common symptoms of ADHD, recognizable before the age of 6, include inattention and/or hyperactivity and excessive impulsivity and problems in social communication and academic performance. In some children this disorder is accompanied by other problems such as anxiety, oppositional defiant disorder, depression or autism spectrum disorder. In particular, this project aims to address the extent to which the diagnosis of ADHD in children and adolescents has repercussions or “spillover effects” that extend beyond the individual affected by this condition.

Thus, in a first study, recently published as work documentWe want to investigate the relationship between ADHD in children/adolescents and the marital stability of their parents. The medical literature has documented a positive association between having ADHD and marital problems or parental divorce (Kvist et al., 2013; Wymbs et al., 2008). However, these findings are mainly based on statistical associations, frequently do not take into account endogeneity issues, and are not conclusions as they often generate mixed results.

To carry out this research we have used the ELSA database (English Longitudinal Study of Aging) which is a representative panel of the population aged 50+ and their partners in England. An important characteristic of ELSA is that in wave 3 a specific interview was conducted with a subsample of participants «Life History Interview», collecting retrospective data on important events that occurred previously in their lives and that may have been momentous, such as the marital status of the parents before turning 16 and the age the interviewees were when their parents divorced. Although ELSA does not include information on the clinical diagnosis of ADHD or its symptoms, it provides extensive and abundant biological and genetic information, including genetic risk scores (or “polygenic Risk Scores” -PGS-) for ADHD, as well as various variables related to ADHD. the family socioeconomic situation and the health of the parents. PGS capture the genetic propensity to suffer from a given condition, and ADHD-related PGS have been shown to be robust predictors of the diagnosis and personality traits of individuals with this condition (Ronald et al., 2021). The great genetic inheritance of these neurodevelopmental disorders should not be ignored, estimated between 70-80% for ADHD (Faraone and Larsson, 2019).

An important advantage of PGS (determined at the time of the child’s conception) is that, consistent with Mendel’s Laws, they are similar to a randomized clinical trial, allowing the inference of a causal effect not confounded by environmental influences. Another advantage is that they are not subject to errors in the diagnosis of ADHD, which are quite common (see, for example, the study by Furzer et al., 2022). Furthermore, unlike diagnosis, PGS better captures the broad and complex spectrum of severity of symptoms related to this condition.

From estimating various “pooled OLS” and panel models with random effects based on a large group of individual, fixed controls and the problem of population stratification (Price et al., 2006), the first results suggest that an increase of one point in the typical reduction in the propensity to develop ADHD increases the probability of parental divorce by 1.4% (taking into account that the average number of divorces in the period considered is 5%, this represents approximately an increase of 25%). Although we have not found very significant differences based on gender, there are notable differences based on the severity of the condition and the age of the individual (see Figure 1), which support the hypothesis that the positive impact of ADHD on the Parental divorce tends to accumulate over time as the child grows as the literatureOur results highlight the importance of mental health interventions for individuals with ADHD that take into account not only the individual in question but the family as a whole.

Figure 1. Impact of ADHD propensity on parental divorce by quintiles of severity of the condition, gender (left panel) and age of the individual (right panel)

In a second phase we want to examine the effects that ADHD has on the mental health of parents. There is abundant evidence showing that parents of children with ADHD are at higher risk for poorer mental health (Peasgood et al., 2020). Isolating the effect of this condition in children on parents’ mental health is a difficult task given the complex interaction on mental well-being within families. For example, some recent studies show that parents of children with ADHD, who are themselves diagnosed with this condition, experience higher levels of mental disorders (van Steijn et al., 2014). Furthermore, recent economics literature has largely focused on studying the effects of a childhood health “shock” on parents’ work outcomes in terms of employment or earnings. This is why the consequences of health disorders that manifest at an early age such as ADHD in broader aspects related to the general well-being of parents is a less explored area of ​​study and that deserves greater attention in the literature. . .