Child Mental Health Research in Low- and Middle-Income Countries: A Twin-Family Feasibility Study in Nigeria.

Globally, most children and adolescents live in low- and middle-income (LAMI) countries. Despite the high and under-recognized mental health burden in these settings, there is little systematic research to inform cost-effective mental health interventions. Identifying causal risk and protective mechanisms is important to inform such interventions. Longitudinal genetically informative designs can help identify potentially causal environmental mechanisms in the etiology of childhood psychopathology but few have been carried out in LAMI settings. We tested the feasibility of a twin-family study in a semi-urban setting in South-Western Nigeria. We recruited 320 family units, each comprising at least one parent and both twins aged 2.5-5.9 (x̄ = 4.0 ± 0.92) years from two towns using five strategies: direct and indirect contacts, radio adverts, cluster sampling (based on local administrative units) and snowball sampling. Participants were asked about their willingness to participate in future research including providing biological samples. These were supplemented with participant engagement activities before and after data collection. Snowball sampling was the most effective strategy while cluster sampling was the least effective (recruiting 46.3% and 8.3% of participants, respectively). Direct contacts and cluster sampling appeared prone to excluding under-represented participants. A large proportion of the participants (98-99%) were willing to participate in future studies. Challenges included grant administration (finance and ethical priorities) and desirability bias. Twin research is feasible in LAMI sub-Saharan Africa, with snowball sampling being an efficient means of recruiting a diverse sample. Participant involvement and engagement is useful to inform the execution of genetically-informative research in a LAMI context.