2 research outputs found
The Intergenerational Transmission Effect of Depression: Causality, Resilience & Decomposition
No full textSince the 1990s, the burden of disease associated with poor mental health has continued to rise in South Africa. One third of South Africans will suffer from poor mental health in their lifetime if either parent also suffers from poor mental health, and this intergenerational transmission effect of depression is large and highly significant. Previous work has attempted to investigate whether it is nurture or nature effects which drive this large transmission effect. While this work has found that it is primarily environmental factors which account for this transmission of depression from mother to child, this does not properly identify the extent of each component, and in which contexts the one is more important than the other. Despite the prevalence of poor mental health, the intergenerational transmission of mental illness in South Africa is equally understudied. Investigating whether this intergenerational transmission of depression is a causal effect or merely a correlation poses a major challenge for inference. This thesis estimates causality in the intergenerational transmission effect of depression from parent to individual, and finds that parental depression is the the single largest determinant of individual depression. That is, individuals with depressed parents are more likely to suffer from depression themselves. This thesis also attempts to explore vulnerability and resilience to this transmission effect and finds that a mother's depression is the largest and most important determinant of transmission of depression from a father. The opposite is also true - a father's depression is the single and largest determinant of transmission of depression from a mother. Upon further investigation of the key determinants of resilience or vulnerability to transmission using the Least Absolute Shrinkage and Selection Operator (lasso) model, this paper finds that hardly any other genetic or environmental characteristics have been found to be significant determinants of transmission. Parental depression alone has the largest effect on whether an individual is resilient or vulnerable to transmission from another parent. This paper finds that the environment does not seem to have as large of an effect on resilience or vulnerability to transmission of depression as was previously thought in the literature - only parental depression seems to have an effect on transmission of depression
Nurture surpasses nature: The intergenerational transmission of depression from African mothers to their adolescent children
No full textMental health in South Africa has been neglected as a public health and policy issue, particularly
among adolescents. This is unfortunate, as nineteen percent of African adolescents in South Africa
suffered from depression in 2014, and these rates were even higher for adolescents with mothers
with poor mental health. Previous work has estimated the impact of parental depression on child
depression in South Africa, and found it to be substantial, particularly for adolescent children. A
teenager whose mother suffers from depression will have a risk of depression which is thirty
percentage points higher than teens whose mothers do not suffer from depression. In order to decide
on the best method of treatment to prevent transmission from occurring, it is necessary to disentangle
the effect into its environmental and genetic components. There is no similar literature on this
relationship in the South African context. This paper investigates the nature of depression
transmission to African adolescents in South Africa, and finds that it is primarily environmental factors
which account for the transmission of depression to children. Using a variety of techniques, we find
that once the “nurture” effect has been accounted for, the “nature” effect is negligible. This implies
that mitigating negative factors in a household, and in communities, as opposed to directly treating
adolescent mental health using conventional approaches, may be the best approach, particularly in a
country struggling with a lack of mental health professionals
