Cookie Preferences
By clicking, you agree to store cookies on your device to enhance navigation, analyze usage, and support marketing. More Info
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.
X
February 4, 2021
The ENIGMA-ADHD Working Group published their second large study on the brains of people with ADHD in the American Journal of Psychiatry this month. In this second study, the focus was on the cerebral cortex, which is the outer layer of the brain.
ADHD symptoms include inattention and/or hyperactivity and acting impulsively. The disorder affects more than one in 20 (5.3%) children, and two-thirds of those diagnosed continue to experience symptoms as adults.
In this study, researchers found subtle differences in the brain’s outer layer - the cortex - when they combined brain imaging data on almost 4,000 participants from 37 research groups worldwide. The differences were only significant for children and did not hold for adolescents or adults. The childhood effects were most prominent and widespread for the surface area of the cortex. More focal changes were found in the thickness of the cortex. All differences were subtle and detected only at a group level, and thus these brain images cannot be used to diagnose ADHD or guide its treatment.
These subtle differences in the brain’s cortex were not limited to people with the clinical diagnosis of ADHD: they were also present - in a less marked form - in youth with some ADHD symptoms. This second finding results from a collaboration between the ENIGMA-ADHD Working Group and the Generation-R study from Rotterdam, which has brain images on 2700 children aged 9-11 years from the general population. The researchers found more symptoms of inattention to be associated with a decrease in cortical surface area. Furthermore, siblings of those with ADHD showed changes to their cortical surface area that resembled their affected sibling. This suggests that familial factors such as genetics or shared environment may play a role in brain cortical characteristics.
This is the largest study to date to look at the cortex of people with ADHD. It included 2246 people with a diagnosis of ADHD and 1713 people without, aged between four and 63 years old. This is the second study published by the ENIGMA-ADHD Working Group; the first examined structures that are deep in the brain. The ADHD Working Group is one of over 50 working groups of the ENIGMA Consortium, in which international researchers pull together to understand the brain alterations associated with different disorders and the role of genetic and environmental factors in those alterations.
The authors say the findings could help improve understanding of the disorder. ‘We identify cortical differences that are consistently associated with ADHD by combining data from many different research groups internationally. We find that the differences extend beyond narrowly-defined clinical diagnoses and are seen, in a less marked manner, in those with some ADHD symptoms and in unaffected siblings of people with ADHD. This finding supports the idea that the symptoms underlying ADHD may be a continuous trait in the population, which has already been reported by other behavioral and genetic studies.’. In the future, the ADHD Working Group hopes to look at additional key features in the brain- such as the structural connections between brain areas – and to increase the representation of adults affected by ADHD, in whom limited research has been performed to date.
See: https://ajp.psychiatryonline.org/doi/10.1176/appi.ajp.2019.18091033
Vitamins play important roles in metabolism, immune regulation, and neurodevelopment. Recent studies show that deficiencies in vitamins like D, B6, B12, and folate are common in people with ADHD and ASD (autism spectrum disorder), and are associated with behavioral, cognitive, and brain development issues.
The Study:
A study team based in China has just performed a systematic search of the peer-reviewed medical literature to perform meta-analyses of clinical trials exploring vitamin interventions in the treatment of ADHD and ASD.
ADHD trials included participants with an official diagnosis. The primary intervention was vitamin supplements, while other treatments, including medications, remained unchanged or were excluded during the study period. ADHD outcomes included measurable changes in ADHD symptoms using validated rating scales and executive function measures.
Eligible studies included standard or sham control groups, crossover, parallel, or other clinical trial designs. In crossover studies, only first-phase data were analyzed to prevent carryover effects.
Ten trials with 852 participants met the standards, but meta-analysis showed no significant results. The outcomes varied widely, suggesting a need to distinguish among vitamins.
Results:
Of the five trials involving 347 participants that specifically evaluated vitamin D supplementation, results indicated a large effect size improvement in ADHD symptoms and executive function measures. The other five studies did not show any observable improvement.
Key limitations include:
The team concluded, “This meta-analysis supports the use of vitamin supplementation as a promising adjunctive treatment for ASD and ADHD. Vitamin B showed greater benefits in improving symptoms of ASD, while vitamin D was more effective in managing ADHD-related behaviors. These findings suggest that specific vitamins may target disorder-specific symptoms. Despite limitations such as the lack of trials on other vitamins and limited understanding of underlying mechanisms, vitamin therapy remains a low-cost, accessible option.”
An important limitation of this work is that the positive results for vitamin D were due to two studies from Iran. So far, no positive study has emerged from a non-Iranian study.
Interpretation:
The vitamin D findings are intriguing and could be important if replicated outside of Iran. Since supplementation is already widely recommended to those with limited sunlight exposure, clinicians may want to consider monitoring their patients’ vitamin D intake, especially in the winter months. It should be noted, however, that due to the limitations of this study, the results are by no means conclusive, and vitamin D should not be taken as a stand-alone treatment for ADHD.
Claims-based real-world data can reveal population-level trends in health among people with neurodevelopmental disorders. This new study examined the prevalence, demographics, and chronic comorbidities of adults and of children and adolescents with ADHD in a large national health plan. It also compared healthcare use and costs between those with and without ADHD.
A research team in the United States conducted an observational cohort study using claims data from more than 1.9 million adults and nearly 500,000 children and adolescents, comparing individuals diagnosed with ADHD to those without the diagnosis.
ADHD was diagnosed in 4% of adults and in 5% of children and adolescents.
Comorbidities By The Numbers:
Disruptive childhood disorders are behavioral problems marked by ongoing defiance, uncooperativeness, and aggression that affect a child's daily life and relationships. The main types, oppositional defiant disorder (ODD) and conduct disorder (CD), involve persistent anger and argumentativeness in ODD, and more severe actions like aggression, cruelty, and criminal behavior in CD. Without treatment, these common childhood disorders can continue into adulthood and raise the risks of substance use, violence, incarceration, and early death.
Disruptive childhood disorders were twenty times more frequent among children and adolescents with ADHD than among those without ADHD diagnosis, and fifteen times more frequent among adults with ADHD.
Bipolar disorder was twelve times more common among children and adolescents with ADHD than those without ADHD, and seven times more common among adults with ADHD.
Schizophrenia was eleven times more prevalent among children and adolescents with ADHD than those without ADHD, and three-and-a-half times more common among adults with ADHD.
Anxiety was nine times more frequent among children and adolescents with ADHD than among those without ADHD diagnosis, and more than five times more frequent among adults with ADHD.
Depression was eight times more common among children and adolescents with ADHD than those without ADHD, and more than five times more common among adults with ADHD.
Suicidal ideation was eight times more prevalent, and suicide attempt seven times more prevalent, among children and adolescents with ADHD than those without ADHD. Both suicidal ideation and suicide attempt were five times more common among adults with ADHD.
Gender dysphoria was almost six times more frequent among children and adolescents with ADHD than among those without ADHD diagnosis, and five times more frequent among adults with ADHD.
Eating disorders were over four times more common among children and adolescents with ADHD than those without ADHD, and five times more common among adults with ADHD.
Substance-related disorders were over six times more prevalent, and alcohol use disorder was six times more prevalent among children and adolescents with ADHD than those without ADHD, and four and three times more prevalent among adults with ADHD.
Increased Costs of Medical Care:
These comorbidities and ADHD led to higher medical costs. Children and adolescents with ADHD spent $610 more annually on healthcare than those without, while adults with ADHD had $1,684 higher average yearly expenditures than non-ADHD adults.
The Take-Away:
This large claims-based analysis of a national commercial insurer found ADHD diagnoses in roughly 4% of adults and 5% of children. It documented substantially higher rates of co-occurring behavioral-health conditions and markedly greater healthcare utilization and expenditures among those with ADHD. The authors report increased odds for several co-occurring diagnoses, as well as higher per-member-per-month (PMPM) spending and per-thousand-per-month (PTPM) utilization, largely driven by greater use of behavioral health services.
Importantly, these results come from cross-sectional, claims data within a commercially insured population: they describe associations, not causal relationships, and may not generalize to uninsured, publicly insured, or otherwise different populations. These findings, therefore, warrant cautious interpretation and highlight the need for longitudinal and more representative studies to clarify drivers of the increased burden and to inform care and policy.
Background:
Since the first in vitro fertilization (IVF) in 1978, assisted reproductive technology (ART) has led to over 10 million births worldwide.
There are four types of embryo transfers, depending on whether they are fresh or frozen, and on their developmental stage.
Fresh cleavage stage embryos are transferred on day 2 or 3 following fertilization and typically contain four to eight relatively large, undifferentiated cells. Fresh blastocyst embryos are transferred on day 5 or 6 after fertilization. At this point, they have developed over a hundred cells and have differentiated into two types: the inner cell mass, which develops into the fetus, and the outer cell layer, which forms the placenta.
Globally, more children are now born through assisted reproductive technology using frozen-thawed embryo transfer than fresh embryo transfer.
Research suggests that ART-conceived offspring may face increased risks of cardiovascular, musculoskeletal, chromosomal, urogenital diseases, and cancers. Might they also be at increased risk for ADHD?
Study:
Taiwan’s single-payer health insurance covers over 99% of people and records all their healthcare activity. Since 1998, it has kept an ART database for all couples registered for IVF treatment.
A Taiwanese research team reviewed all records for the five-year period from 2013 through 2017, ultimately analyzing 3,125 live singleton births from fresh cleavage stages, 1,332 from fresh blastocysts, 1,465 from frozen cleavage stages, and 4,708 from frozen blastocysts, alongside 878,643 naturally conceived singleton births.
The team controlled for the following potential confounders: pregnancy-induced hypertension, chronic hypertension, diabetes mellitus, gestational diabetes mellitus, unhealthy lifestyle, placenta previa, placenta abruption, preterm premature rupture of membrane, and postpartum hemorrhage.
Results:
With these adjustments, cleavage stage embryo transfers, whether fresh or frozen, were associated with a seven-fold higher rate of ADHD diagnosis in offspring than natural conception.
Frozen blastocyst embryo transfers were likewise linked to a seven-fold increase in ADHD diagnoses in offspring compared to natural conception. Notably, fresh blastocyst transfers showed a 19-fold increase, likely due to the smaller number of cases in this category.
The team concluded, “Compared to natural conception, ART is associated with higher risks, particularly for preterm birth, ADHD, and developmental delay.”
Conclusion:
This large national cohort suggests that ART-conceived singletons face higher rates of several adverse outcomes, including preterm birth, ADHD, and developmental delay. Clinicians and prospective parents should therefore weigh these potential associations when counseling and planning care, prioritize optimized ART protocols and perinatal management, and ensure early developmental surveillance for ART-conceived children so concerns can be identified and addressed promptly.
It is important to note that the findings also point to the likely contribution of underlying parental infertility in these developmental outcomes. Future research should aim to disentangle parental- versus procedure-related risks to clarify absolute risk magnitudes. As always, associations of this time should not be interpreted as causal due to the inability of observational studies to rule out all possible confounding factors.
_logo%201.svg)
