The influence of Executive Function on Mental Health in vulnerable adolescents: a multi-site low and middle income country approach

Executive function (EF) regulates emotions, thoughts and behaviours, and difficulties in EF have been strongly implicated in mental health problems in high income countries (HICs). EF includes a set of cognitive skills such as working memory, cognitive flexibility, selective attention and inhibition which form the building blocks for higher order cognitive functions such as reasoning, planning every day activities and problem solving. EF is therefore critical in emotional, behavioural, cognitive, and social functioning and interpersonal relationships. Poor EF has wide ranging implications in a number of important areas; in particular, it is associated with increased rates of mental health disorders such as depression, anxiety and attention deficit hyperactivity disorder. There are two periods during which development of EF is rapid; childhood and adolescence. These are critical time points to intervene and prevent impairments in EF.

Poor EF can result from biomedical factors, such as poor nutrition or exposure to HIV and malaria or from exposure to poverty, particularly when this occurs during periods of rapid EF development. These risk factors will affect both individuals' performance on EF tasks as well as the neural substrates of EF. The high level of socioeconomic adversity and the presence of multiple risk factors will have a strong influence on adolescents' achieving their potential and will impact their contributions to society through employment, social functioning, mental and physical health.

Investigators across multiple Departments at the University of Oxford have over a number of years concentrated on the relationship between EF, mental health and risk taking behaviours such as (unprotected sex, alcohol or drug use). Research in this area is being carried out in collaboration with investigators in multiple Low and Middle Income Countries (LMIC): by Abubakar and Newton in Kenya; Kahn, Scerif, Demeyere and Stein in South Africa; Favara, Sanchez and Pankhurst in Ethiopia and Peru.

This proposal will create a platform for UK and LMIC researchers working on EF and mental health, the harmonisation of EF tools currently used across sites and it will enable the piloting of a new EF measure to allow for the comparison of EF and its association with mental health data across sites. A number of studies have shown that EF can be improved in children and adolescents either through direct stimulation (e.g. EF-specific training tasks) or through enhancing their psychosocial environment, but not all these interventions may be financially viable or culturally acceptable in LMICs. A necessary step before intervening is to ensure we have accurate tools which reliably measure EF across settings and cultures, and that the cultural acceptability of relevant interventions is assessed.

As part of this proposal, we will refine our measurement tools and investigate contextually appropriate interventions to improve EF, during one of the critical periods of EF development i.e. adolescence. Improving EF in adolescence will ensure they will be able to take advantage of school education and it will allow for informed relational and occupational choices, as well as reduce the risk of high-risk sexual and substance use behaviours and promote physical and mental health.

Executive function (EF) is complex set of skills which have three core functions: inhibition and interference control, working memory and cognitive flexibility. These functions are used for reasoning, problem solving, and planning everyday activities. EF is critical for children's development, influencing cognitive, academic and social functioning. Impairment is associated with mental illness such as anxiety, attention deficit hyperactivity disorder and depression. It has two periods of rapid development i.e. early childhood and adolescence.
Biomedical factors, such as a poor nutritional status and HIV, adversely affect both the neural substrates of EF and performance on EF tasks. In addition, chronic poverty affects EF through exposure to multiple psychosocial stressors. These factors are common in Low and Middle Income Countries (LMIC) and are likely to be major determinants of adolescents achieving their potential, being able to contribute to society through employment and social functioning, and achieving mental health.
The role of EF in risky behaviour and mental health is a strong focus of investigators across multiple Departments at the University of Oxford. Research in this area is already being carried out in collaboration with investigators in LMIC by Abubakar and Newton in Kenya; Kahn and Scerif, Demeyere and Stein in South Africa; Favara and Sanchez in Ethiopia and Peru.
The pump priming grant allows these different groups to develop a common assessment platform and develop strategies to improve EF to enhance mental health and decrease risk behaviours. A key component of the work will be the harmonisation of instruments to measure EF in LMIC. Numerous studies have shown that EF can be improved; either through direct cognitive stimulation or indirectly through enhancing the psychosocial environment, and we plan to identify contextually appropriate interventions to improve EF in adolescence.

This research will harmonise the tools to measure executive function (EF) and mental health in adolescents in four low and middle income countries (LMIC). Representatives and collaborators at each site already engage in exchanges with the local communities with whom they work, as well as reporting findings to policy makers and educators.

The study will directly benefit families of adolescents in these countries, by raising issues around decision making and mental health. Those that are identified with mental illnesses will be referred to appropriate services, thus improving health and well-being. Local reports / stakeholder meetings will summarise the study findings to participants and their communities.

It will provide tools to measure EF and mental health in vulnerable adolescents across diverse cultures and settings. These tools will be made available to the scientific community to be tested and adapted according to local conditions. In addition the sites will directly benefit from the development and harmonisation of these tools, in that the tools can be used in the established cohorts to provide insights in the behaviour and mental health of the adolescents.

This project will provide an opportunity for a post-doctoral student to develop research proposals examining the role of executive function in mental illness amongst vulnerable adolescents living in LMIC. In particular this project forms the basis of identifying tools to improve EF, so as enhance appropriate decisions made by the adolescents that will affect their well-being, mental health, economic potential through career choices. This will reduce their vulnerability to the adverse environment in which many of them grow up. Impact will be maximised by making future collaborations by LMIC-based projects and researchers aiming to use this new tool to investigate EF.

The University of Oxford will benefit from these studies by its members gaining experience in conducting studies in LMIC. This meets its vision to benefit society on a national and a global scale (https://www.ox.ac.uk/about/organisation/strategic-plan?wssl=1) and addresses both of its priorities for the strategic plan of 2013-18 i.e. to promote global reach by developing a global forum for intellectual engagement; and to build on Oxford's multiple disciplinary strengths to enable collaborations in new and developing areas.

The analysed data will be publicised in peer-reviewed scientific publications, as we have done in previous projects, maximising impact with researchers working in LMICs.