Migration modulates the prevalence of ASD and ADHD: a systematic review and meta-analysis

Abstract

Background Migration has been implicated as a risk factor for autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD), but evidence is still limited and inconsistent. We aim to investigate the relationship between migration status and risk of ASD and ADHD. Methods Electronic databases including PubMed, EMBASE, Web of Science, and PsychINFO were searched to identify observational studies on this topic, from inception to February 2021. Random-effects meta-analysis models were used to pool the summary odds ratio (OR) and 95% confidence interval (95% CI), and subgroup analyses were conducted to detect possible discrepancies in associations. Certainty of evidence was assessed as per the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) guidelines. Results A total of 13 studies (6,532,546 participants) for ASD, five studies (2,875,070 participants) for ADHD, and six studies (31,158 participants) for hyperactivity were included. Overall, the pooled results indicated that migration was associated with increased risk of ASD (pooled OR: 1.32; 95% CI: 1.07–1.63; P for Z test = 0.010), but no association was found between migration and ADHD (pooled OR: 0.84; 95% CI: 0.53–1.32; P for Z test = 0.452) or hyperactivity (pooled standardized mean difference: -0.073; 95% CIs: − 0.383–0.236; P for Z test = 0.642). Subgroup analyses further demonstrated that maternal migration was ASD risk factor (pooled OR: 1.49; 95% CI: 1.19–1.87), and migrant children were more likely to develop ASD with comorbid intellectual disability (ID) (pooled OR: 1.21, P for interaction = 0.006) than ASD without ID. After standardized the origin of migrants, European migrant children from Americas were at higher risk of ASD and ADHD (pooled OR were 4.13 and 1.26), and increased ASD risk was also observed in African children (pooled OR: 2.72). The GRADE of evidence was very low. Conclusions Maternal migration is a risk factor for ASD, and migrant ASD children are more likely comorbid ID. The role of migration on ADHD remains controversial, more studies are needed to assess the association between migration status and ADHD. Health care practitioners should consider screening and providing extra resources for migrant children.

Who Is Attending? The Role of Child Ethnicity and Maternal Demographics in Research Engagement and Early Identification of Autism

“…This was also found in a population-based Australian study that investigated the prevalence of developmental disabilities, finding that the impact of maternal migration acted in two ways—it increased the likelihood factor of diagnosis with autism with ID for children of non-Australian-born women from low- and middle-income countries, but was also as a protective factor for children of non-Australian-born mothers for diagnosis of developmental disabilities overall [ 19 ]. This was further evident in a 2022 systematic review on migration and autism prevalence, which found maternal migration increased the likelihood of an autism diagnosis, with migrant autistic children more likely to also be diagnosed with co-occurring ID [ 20 ].…”

Heavy migration of flood affectees in Pakistan and increased risk of autism spectrum disorder in children: a call to action

“…According to current estimates, ASD affects up to 1 in 36 children worldwide, and 75% of those children also have one or more co-occurring mental health conditions, such as attention-deficit hyperactivity disorder, bipolar disorder, depression, or anxiety 3 . It has been observed that several hereditary variables, such as parental age, maternal stress, smoking, exposure to certain drugs, and improper brain development during pregnancy may raise the chance of ASD in developing children 4 . Moreover, low birth weight, metal exposure, and a sibling with autism also account for a high risk of developing ASD 5 .…”

“…Research has suggested that migrant parents are more prone to having ASD in their children than non-migrants 4 . A study by Mughal et al 6 , concluded that children of immigrants exhibit unpleasant behavior when exposed to geographic differences because they have weaker or less adaptive abilities.…”

“…A study by Mughal et al 6 , concluded that children of immigrants exhibit unpleasant behavior when exposed to geographic differences because they have weaker or less adaptive abilities. Maternal migration during pregnancy increases the risk of ASD in kids 4 , 7 . Migration is a challenging and diverse process that involves a variety of elements.…”

Overview of Services for Autism Spectrum Disorders (ASD) in Low- and Middle-Income Countries (LMICs) and among Immigrants and Minority Groups in High-Income Countries (HICs)

“…There is a documented dearth of ASD studies among immigrants and minority groups in HICs [ 27 ]. Hence, the evidence supports ethnic and racial variances in ASD prevalence and access to services, even among the HICs and developed societies.…”