September 8, 2025

Registry-based Cohort Study Finds No Association Between Maternal Diabetes and Offspring ADHD

Background:

A previous meta-analysis found that children born to mothers with diabetes had a 34% higher risk of developing ADHD compared to those born to non-diabetic mothers.  

However, previous studies suffered methodological limitations, such as small sample sizes, case-control or cross-sectional designs, and insufficient adjustment for key confounders such as maternal socio-economic status, mental health conditions, obesity, and substance use disorders.  

Moreover, many studies relied on self-reported maternal diabetes, and on non-clinical ADHD assessments, such as parental reports or screening tools, which are prone to bias and inaccuracies.  

Furthermore, the role of maternal antidiabetic medication use in relation to ADHD risk has rarely been examined. Antidiabetic medications are effective in controlling high blood sugar during pregnancy, but many can cross the placenta and the blood-brain barrier, raising concerns about potential effects on fetal brain development.  

Study:

To address these gaps, an Australian study team used a large cohort of linked health administrative data from New South Wales to investigate both the association between maternal diabetes and the risk of ADHD and the independent effect of prenatal exposure to antidiabetic medications. 

The study encompassed all mother-child pairs born from 2003 through 2005, with follow-up conducted through 2018 to monitor hospital admissions related to ADHD. That yielded a final cohort of almost 230,000 mother-child pairs. 

The team adjusted for potential confounders including maternal age, socioeconomic status, previous children, pregnancy-related hypertension, caesarean delivery, birth order and plurality, maternal anxiety, depression, schizophrenia, bipolar disorder, substance use (alcohol, tobacco, stimulants, opioids, cannabis), and child factors such as Apgar score, sex, prematurity, and low birth weight. 

Results:

For maternal diabetes overall, there was no significant association with offspring ADHD. That was also true when broken down into pre-existing maternal diabetes and gestational (pregnancy-induced) diabetes.  

In a subset of 11,668 mother-child pairs, including 3,210 involving exposure to antidiabetic medications, there was likewise no significant association with offspring ADHD

Conclusion:

The team concluded, “Our findings did not support the hypothesis that maternal diabetes increases the risk of ADHD in children. Additionally, maternal use of antidiabetic medication was not associated with ADHD.” 

This study highlights the importance of high-quality research. A previous meta-analysis linking ADHD and maternal diabetes did not appropriately adjust for confounders and cited many small studies that may have included biased self-report scales. This large, registry-based cohort study of nearly 230,000 mother–child pairs found no evidence that maternal diabetes—whether pre-existing or gestational—or prenatal exposure to antidiabetic medications was associated with subsequent offspring ADHD as measured by hospital-recorded ADHD outcomes. The study’s strengths include its population scale, prolonged follow-up, and extensive adjustment for maternal and perinatal confounders (including maternal mental health and substance-use disorders), which address many limitations of earlier, smaller studies that reported elevated risks.  

Yitayish Damtie, Kim Betts, Berihun Assefa Dachew, Getinet Ayanoa, and Rosa Alati, “The association between maternal diabetes, antidiabetic medication use, and severe ADHD requiring inpatient care: A registry-based cohort study,” Journal of Psychosomatic Research (2025), 195:112167, https://doi.org/10.1016/j.jpsychores.2025.112167

Related posts

CDC: ADHD Diagnosis, Treatment, and Telehealth Use in Adults

The report "Attention-Deficit/Hyperactivity Disorder Diagnosis, Treatment, and Telehealth Use in Adults" published in the CDC's Morbidity and Mortality Weekly Report provides a detailed examination of the prevalence and treatment of ADHD among U.S. adults based on data collected by the National Center for Health Statistics Rapid Surveys System during October–November 2023. This data is crucial as it offers updated estimates on the prevalence of ADHD in adults, a condition often regarded as primarily affecting children, and highlights the ongoing challenges in accessing ADHD-related treatments, including telehealth services and medication availability.

Methods:

The methods used in this study involved the National Center for Health Statistics (NCHS) Rapid Surveys System (RSS), which gathers data to approximate the national representation of U.S. adults through two commercial survey panels: the AmeriSpeak Panel from NORC at the University of Chicago and Ipsos’s KnowledgePanel. The data were collected via online and telephone interviews from 7,046 adults. The responses were weighted to reflect the total U.S. adult population, ensuring that the results approximate national estimates. In identifying adults with current ADHD, respondents were asked if they had ever been diagnosed with ADHD and, if so, whether they currently had the condition. The study also collected data on treatment types (including stimulant and nonstimulant medications), telehealth use, and demographic variables such as age, education, race, and household income.

Results:

The results showed that approximately 6.0% of U.S. adults, or an estimated 15.5 million people, had a current ADHD diagnosis. Notably, more than half of the adults with ADHD reported receiving their diagnosis during adulthood (age ≥18 years), indicating that diagnosis can occur well beyond childhood. Analysis of demographics showed significant differences between adults with ADHD and those without; adults with ADHD were more likely to be younger, with 84.5% under the age of 50. Adults with ADHD were also less likely to have completed a bachelor's degree and more likely to have a household income below the federal poverty level compared to those without ADHD. Regarding treatment, the report found that approximately one-third of adults with ADHD were untreated, and around one-third received both medication and behavioral treatment. Among those receiving pharmacological treatment, 33.4% used stimulant medications, and 71.5% of these individuals reported difficulties in getting their prescriptions filled due to medication unavailability, reflecting recent stimulant shortages in the United States. Additionally, nearly half of adults with ADHD had used telehealth services for ADHD-related care, including obtaining prescriptions and receiving counseling or therapy.

The discussion emphasizes the public health implications of these findings. ADHD is often diagnosed late, with many individuals not receiving a diagnosis until adulthood, which underscores the need for improved awareness and early identification of ADHD symptoms across the life course. Moreover, the high prevalence of untreated ADHD and the barriers to accessing stimulant medications reveal significant gaps in the healthcare system's ability to support adults with ADHD. These gaps can contribute to poorer outcomes, such as increased risk of injury, substance use, and social impairment. The report also highlights the role of telehealth, which became more prominent during the COVID-19 pandemic. Telehealth appears to provide a viable solution for expanding access to ADHD diagnosis and treatment, though challenges remain regarding the quality of care and potential for misuse. The authors suggest that improved clinical care guidelines for adults with ADHD could help reduce delays in diagnosis and treatment access, thus improving long-term outcomes for affected individuals.

Conclusion:

In conclusion, the study provides a comprehensive view of the prevalence, treatment, and telehealth use for ADHD among adults in the U.S.  These data are crucial for guiding clinical care and shaping policies related to medication access and telehealth services. The findings underscore the importance of ensuring an adequate supply of stimulant medications and reducing barriers to ADHD care, ultimately enhancing the quality of life for adults with this condition.   The good news is that many adults with ADHD are being diagnosed and treated.  It is, however, concerning that many are not treated and that many of those treated with stimulants were impacted by the stimulant shortage.

For more details, see:   https://www.cdc.gov/mmwr/volumes/73/wr/mm7340a1.htm

October 14, 2024

Combined meta-analysis and nationwide population study indicates ADHD by itself has negligible effect on risk of type 2 diabetes

Study Indicates ADHD By Itself Has Negligible Effect on Risk of Type 2 Diabetes

Noting that “evidence on the association between ADHD and a physical condition associated with obesity, namely type 2 diabetes mellitus (T2D), is sparse and has not been meta-analysed yet,” a European study team performed a systematic search of the peer-reviewed medical literature followed by a meta-analysis, and then a nationwide population study.

Unlike type 1 diabetes, which is an auto-immune disease, type 2 diabetes is believed to be primarily related to lifestyle, associated with insufficient exercise, overconsumption of highly processed foods, and especially with large amounts of refined sugar. This leads to insulin resistance and excessively high blood glucose levels that damage the body and greatly lower life expectancy.

Because difficulty with impulse control is a symptom of ADHD, one might hypothesize that individuals with ADHD would be more likely to develop type-2 diabetes. 

The meta-analysis of four cohort studies encompassing more than 5.7 million persons of all ages spread over three continents (in the U.S., Taiwan, and Sweden) seemed to point in that direction. It found that individuals with ADHD had more than twice the odds of developing type 2 diabetes than normally developing peers. There was no sign of publication bias, but between-study variability (heterogeneity) was moderately high.

The nationwide population study of over 4.2 million Swedish adults came up with the same result when adjusting only for sex and birth year. 

Within the Swedish cohort there were 1.3 million families with at least two full siblings. Comparisons among siblings with and without ADHD again showed those with ADHD having more than twice the odds of developing type 2 diabetes. That indicated there was little in the way of familial confounding.

However, further adjusting for education, psychiatric comorbidity, and antipsychotic drugs dropped those higher odds among those with ADHD in the overall population to negligible (13% higher) and barely significant levels. 

The drops were particularly pronounced for psychiatric comorbidities, especially anxiety, depression, and substance use disorders, all of which had equal impacts.

The authors concluded, “This study revealed a significant association between ADHD and T2D [type 2 diabetes] that was largely due to psychiatric comorbidities, in particular SUD [substance use disorders], depression, and anxiety. Our findings suggest that clinicians need to be aware of the increased risk of developing T2D in individuals with ADHD and that psychiatric comorbidities may be the main driver of this association. Appropriate identification and treatment of these psychiatric comorbidities may reduce the risk for developing T2D in ADHD, together with efforts to intervene on other modifiable T2D risk factors (e.g., unhealthy lifestyle habits and use of antipsychotics, which are common in ADHD), and to devise individual programs to increase physical activity. Considering the significant economic burden of ADHD and T2D, a better understanding of this relationship is essential for targeted interventions or prevention programs with the potential for a positive impact on both public health and the lives of persons living with ADHD.”

Undiagnosed ADHD May Be Undermining Diabetes Control in Adults with Type 1 Diabetes

Our recent study, published in the Journal of Clinical Medicine, aims to shed light on an under-recognized challenge faced by many adults with Type 1 diabetes (T1D): attention-deficit/hyperactivity disorder (ADHD) symptoms.

We surveyed over 2,000 adults with T1D using the Adult Self-Report Scale (ASRS) for ADHD and analyzed their medical records. Of those who responded, nearly one-third met the criteria for ADHD symptoms—far higher than the general population average. Notably, only about 15% had a formal diagnosis or were receiving treatment.

The findings are striking: individuals with higher ADHD symptom scores had significantly worse blood sugar control, as indicated by higher HbA1c levels. Those flagged as "ASRS positive" were more than twice as likely to have poor glycemic control (HbA1c ≥ 8.0%). They also reported higher levels of depressive symptoms.

As expected, ADHD symptoms decreased with age but remained more common than in the general public. No strong links were found between ADHD symptoms and other cardiometabolic issues.

This study highlights a previously overlooked yet highly significant factor in diabetes management. ADHD-related difficulties—such as forgetfulness, inattention, or impulsivity—can make managing a complex condition like T1D more difficult. The researchers call for more screening and awareness of ADHD in adults with diabetes, which could lead to better mental health and improved blood sugar outcomes.

Takeaway: If you or a loved one with T1D struggles with focus, organization, or consistent self-care, it may be worth exploring whether ADHD could be part of the picture. Early identification and support are crucial to managing this common comorbidity. 

July 10, 2025

Taiwan Nationwide Population Study Concludes Dopaminergic ADHD Medications Reduce Risk of Myopia

The Background:

Myopia is a growing global health concern linked to conditions like macular degeneration, glaucoma, and retinal detachment. Its prevalence has surged in recent decades; by 2050, an estimated 5 billion people will have myopia. The increase is especially marked in Asia – a survey in Taiwan reports that 84% of students aged 15 to 18 are myopic, with 24% severely affected. 

Dopamine is an important neurotransmitter in the retina, involved in eye development, visual signaling, and refractive changes. The dopamine hypothesis, suggesting that retinal dopamine release helps prevent myopia, has emerged as a leading theory of myopia control. 

Most studies show ADHD is highly heritable, often involving dopamine system genes. ADHD is strongly associated with dopaminergic abnormalities, especially in dopamine transporter function and release dynamics. 

Medications for ADHD, like methylphenidate, atomoxetine, and clonidine, help regulate dopamine to reduce symptoms.  

The Study:

Given dopamine’s critical involvement in both ADHD and myopia, a Taiwanese research team hypothesized that medications for ADHD that influence dopaminergic pathways may have a significant effect on myopia risk.  

To evaluate this hypothesis, the team conducted a nationwide cohort study using data from Taiwan’s National Health Insurance (NHI) program, which covers 99% of the nation’s 23 million residents and provides access to comprehensive eye care and screenings. Taiwan requires visual acuity screenings beginning at age four, with annual examinations for school-aged children to promote the early detection of visual anomalies such as myopia.  

Furthermore, ADHD medication and diagnosis are tracked through compulsory diagnostic codes. This permits an accurate assessment of the effects of dopaminergic medications on myopia risk. 

Propensity score allocation using a multivariable logistic regression model was applied to reduce bias from confounding influences, pairing cohorts based on similar scores. 

The Results: 

Comparing 133,945 individuals with ADHD with an equal number without ADHD, untreated ADHD was associated with a 22% greater risk of myopia.  

However, after adjusting for covariates (gender, age, insured premium, comorbidities, location, and urbanization level), the ADHD cohort receiving medication treatment showed a 39% decreased risk of myopia relative to the untreated ADHD cohort. 

Narrowing this further to the ADHD cohort receiving dopaminergic medications reduced the risk of myopia by more than half (52%) relative to the untreated ADHD cohort.  

Treatment with two dopaminergic medications reduced the risk by well over two-thirds (72%) relative to the untreated ADHD cohort. 

There were no significant differences between methylphenidate, atomoxetine, and clonidine. Each reduced risk by about 50%. 

The team did not directly compare the ADHD cohort receiving dopaminergic medications with the non-ADHD cohort. But if there were 122 cases of myopia in the ADHD cohort for every 100 cases in the non-ADHD cohort, and dopaminergic medications halved the cases in the ADHD cohort to about 60, that would represent a roughly 40% reduction in myopia risk relative to the non-ADHD cohort. 

The team concluded, “our research indicates that pharmacologically treated ADHD children have a reduced risk of myopia. Conversely, untreated ADHD children are at a heightened risk relative to those without ADHD. Moreover, the cumulative effects of ADHD medications were found to notably decrease myopia incidence, emphasizing the protective influence of dopaminergic modulation in these interventions.” 

The Take-Away:

Children with untreated ADHD are more likely to develop myopia, but those receiving dopaminergic medications had a substantially lower risk. The findings suggest that ADHD medications may help protect against myopia by boosting dopamine signaling. More research is needed before firmly drawing this conclusion, but this research could open the door to new approaches for preventing myopia in at-risk children.

December 8, 2025

Two New Meta-analyses Point to Benefits of Transcranial Direct Current Stimulation

Background: 

ADHD treatment includes medication, behavioral therapy, dietary changes, and special education. Stimulants are usually the first choice but may cause side effects like appetite loss and stomach discomfort, leading some to stop using them. Cognitive behavioral therapy (CBT) is effective but not always sufficient on its own. Research is increasingly exploring non-drug options, such as transcranial direct current stimulation (tDCS), which may boost medication effectiveness and improve results. 

What is tDCS?

tDCS delivers a weak electric current (1.0–2.0 mA) via scalp electrodes to modulate brain activity, with current flowing from anode to cathode. Anodal stimulation increases neuronal activity, while cathodal stimulation generally inhibits it, though effects vary by region and neural circuitry. The impact of tDCS depends on factors such as current intensity, duration, and electrode shape. It targets cortical areas, often stimulating the dorsolateral prefrontal cortex for ADHD due to its role in cognitive control. Stimulation of the inferior frontal gyrus has also been shown to improve response inhibition, making it another target for ADHD therapy. 

There is an ongoing debate about how effective tDCS is for individuals with ADHD. One study found that applying tDCS to the left dorsolateral prefrontal cortex can help reduce impulsivity symptoms in ADHD, whereas another study reported that several sessions of anodic tDCS did not lead to improvements in ADHD symptoms or cognitive abilities.  

New Research:

Two recent meta-analyses have searched for a resolution to these conflicting findings. Both included only randomized controlled trials (RCTs) using either sham stimulation or a waitlist for controls. 

Each team included seven studies in their respective meta-analyses, three of which appeared in both. 

Both Wang et al. (three RCTs totaling 97 participants) and Wen et al. (three RCTs combining 121 participants) reported very large effect size reductions in inattention symptoms from tDCS versus controls. There was only one RCT overlap between them. Wang et al. had moderate to high  variation (heterogeneity) in individual study outcomes, whereas Wen et al. had virtually none. There was no indication of publication bias. 

Whereas Wen et al.’s same three RCTs found no significant reduction in hyperactivity/impulsivity symptoms, Wang et al. combined five RCTs with 221 total participants and reported a medium effect size reduction in impulsivity symptoms. This time, there was an overlap of two RCTs between the studies. Wen et al. had no heterogeneity, while Wang et al. had moderate heterogeneity. Neither showed signs of publication bias.  

Turning to performance-based tasks, Wang et al. reported a medium effect size improvement in attentional performance from tDCS over controls (three RCTs totaling 136 participants), but no improvement in inhibitory control (five RCTs combining 234 persons). 

Wang et al. found no significant difference in adverse events (four RCTs combining 161 participants) between tDCS and controls, with no heterogeneity. Wen et al. found no significant difference in dropout rates (4 RCTs totaling 143 individuals), again with no heterogeneity.  

Wang et al. concluded, “tDCS may improve impulsive symptoms and inattentive symptoms among ADHD patients without increasing adverse effects, which is critical for clinical practice, especially when considering noninvasive brain stimulation, where patient safety is a key concern.” 

Wen et al. further concluded, “Our study supported the use of tDCS for improving the self-reported symptoms of inattention and objective attentional performance in adults diagnosed with ADHD. However, the limited number of available trials hindered a robust investigation into the parameters required for establishing a standard protocol, such as the optimal location of electrode placement and treatment frequency in this setting. Further large-scale double-blind sham-controlled clinical trials that include assessments of self-reported symptoms and performance-based tasks both immediately after interventions and during follow-up periods, as well as comparisons of the efficacy of tDCS targeting different brain locations, are warranted to address these issues.” 

The Take-Away: 

Previous studies have shown mixed results on the benefits of this therapy on ADHD. These new findings suggest that tDCS may hold some real promise for adults with ADHD. While the technique didn’t meaningfully shift hyperactivity or impulsivity, it was well-tolerated and showed benefit, especially in self-reported symptoms. However, with only a handful of trials to draw from, it would be a mistake to suggest tDCS as a standard treatment protocol. Larger, well-designed studies are the next essential step to clarify where, how, and how often tDCS works best.

Meta-analysis Reports Executive Function Gains from Exercise Interventions for ADHD

Background:

The development of ADHD is strongly associated with functional impairments in the prefrontal cortex, particularly the dorsolateral prefrontal cortex, which plays a key role in maintaining attention and controlling impulses. Moreover, imbalances in neurotransmitters like dopamine and norepinephrine are widely regarded as major neurobiological factors contributing to ADHD. 

Executive functions are a group of higher-order cognitive skills that guide thoughts and actions toward goals. “Executive function” refers to three main components: inhibitory control, working memory, and cognitive flexibility. Inhibitory control helps curb impulsive actions to stay on track. Working memory allows temporary storage and manipulation of information for complex tasks. Cognitive flexibility enables switching attention and strategies in varied or demanding situations. 

Research shows that about 89% of children with ADHD have specific executive function impairments. These difficulties in attention, self-control, and working memory often result in academic and social issues. Without timely intervention, these issues can lead to emotional disorders like depression, anxiety, and irritability, further affecting both physical health and social development. 

Currently, primary treatments for executive function deficits in school-aged children with ADHD include medication and behavioral or psychological therapies, such as Cognitive Behavioral Therapy (CBT). While stimulant medications do improve executive function, not all patients are able to tolerate these medications. Behavioral interventions like neurofeedback provide customized care but show variable effectiveness and require specialized resources, making them hard to sustain. Safer, more practical, and long-lasting treatment options are urgently needed. 

Exercise interventions are increasingly recognized as a safe, effective way to improve executive function in children with ADHD. However, systematic studies on school-aged children remain limited.  

Moreover, there are two main scoring methods for assessing executive function: positive scoring (higher values mean better performance, such as accuracy) and reverse scoring (lower values mean better performance, such as reaction time). These different methods can affect how results are interpreted and compared across studies. This meta-analysis explored how different measurement and scoring methods might influence results, addressing important gaps in the research. 

The Study:

Only randomized controlled trials (RCTs) involving school-aged children (6–13 years old) diagnosed with ADHD by DSM-IV, DSM-5, ICD-10, ICD-11, or the SNAP-IV scale were included. Studies were excluded if the experimental group received non-exercise interventions or exercise combined with other interventions. 

Cognitive Flexibility 

Using positive scoring, exercise interventions were associated with a narrowly non-significant small effect size improvement relative to controls (eight RCTs, 268 children). Using reverse scoring, however, they were associated with a medium effect size improvement (eleven RCTs, 452 children). Variation (heterogeneity) in individual RCT outcomes was moderate, with no sign of publication bias in both instances. 

Inhibitory Control 

Using positive scoring, exercise interventions were associated with a medium effect size improvement relative to controls (ten RCTs, 421 children). Using reverse scoring, there was an association with a medium effect size improvement (eight RCTs, 265 children). Heterogeneity was moderate with no sign of publication bias in either case. 

Working Memory 

Using positive scoring, exercise interventions were associated with a medium effect size improvement relative to controls (six RCTs, 321 children). Using reverse scoring, the exercise was associated with a medium effect size improvement (five RCTs, 143 children). Heterogeneity was low with no indication of publication bias in both instances. 

Conclusion:

The team concluded, “Exercise interventions can effectively improve inhibitory control and working memory in school-aged children with ADHD, regardless of whether positive or reverse scoring methods are applied. However, the effects of exercise on cognitive flexibility appear to be limited, with significant improvements observed only under reverse scoring. Moreover, the effects of exercise interventions on inhibitory control, working memory, and cognitive flexibility vary across different measurement paradigms and scoring methods, indicating the importance of considering these methodological differences when interpreting results.” 

Although this work is intriguing, it does not show that exercise significantly improves the symptoms of ADHD in children. This means that exercise, although beneficial for many reasons, should not be viewed as a replacement for evidence-based treatments for the disorder.

December 3, 2025