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.”

Miguel Garcia-Argibay, Lin Li, Ebba Du Rietz, Le Zhang, Honghui Yao, Johan Jendle, Josep A. Ramos-Quiroga, Marta Ribasés, Zheng Chang, Isabell Brikell, Samuele Cortese, Henrik Larsson, “In utero exposure to ADHD medication and long-term offspring outcomes,” Neuroscience and Biobehavioral Reviews (2023), 147:105076, https://doi.org/10.1016/j.neubiorev.2023.105076.

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Nationwide population study finds cancer survivors have much higher risk of ADHD

Nationwide Population Study Finds Cancer Survivors Have Much Higher Risk of ADHD

Thanks to improvements in cancer treatment, there is a growing population of childhood and adolescent cancer survivors (CACSs). CACSs are at an increased risk of chronic physical, psychological, and social problems because of their cancer experiences and intensive cancer treatments. These include depression, anxiety, suicidal ideation, and post-traumatic stress disorder (PTSD). 

To what extent, if at all, does this also apply to ADHD? Noting that “previous studies … have reported inconsistent findings,” a local research team took advantage of Taiwan’s mandatory single-payer National Health Insurance that covers over 99% of the island’s population. More specifically, the National Health Insurance Research Database (NHIRD) maintains data on the insured population available on formal request for study purposes.

Linking the catastrophic illness database, mental disorders database, and longitudinal health insurance database, they tracked children age younger than 10 years and adolescents aged 11-17 years who were diagnosed with any malignancy (cancer) between 2002 and 2011 with no history of major psychiatric disorders (including ADHD). Parental history of major psychiatric disorders was likewise controlled as a potential confounder.

The team identified 5,121 CACSs, which they matched one to ten with 51,210 age-, sex-, income-, and residence-matched cancer-free controls.

ADHD diagnoses were made by board-certified psychiatrists during the study follow-up period (from enrollment through 2011) based on a comprehensive clinical interview and clinical judgment. 

Cancer survivors were diagnosed with ADHD at more than six times the rate of matched controls. Survival duration made no significant difference in this outcome. 

Cancers of bone, connective tissue, skin, and breast were associated with a more than threefold increase in risk of an ADHD diagnosis. For cancers of the circulatory system, there was a more than sixfold increased risk of ADHD, and for those of the genitourinary organs, more than sevenfold increased risk. 

For brain cancer survivors, the increased risk of ADHD was more than twelvefold. That may be at least in part because the brain itself was targeted for treatment in these instances, which plausibly could cause damage resulting in psychiatric disorders.

The team concluded, “we observed a comparatively higher risk of MPDs [major psychiatric disorders] among CACSs than among controls and likewise found that such risks varied across different cancer types. Survivors of both CNS [central nervous system] and non-CNS cancers have increased risks of MPD diagnoses. Among the enrolled CACSs, ASD [autism spectrum disorder] and ADHD were associated with most types/categories of cancers. Long-term care of this vulnerable population must include psychosocial interventions for patients and their families. Physicians need to be aware of early signs of mental health problems in this high-risk subpopulation and arrange early interventions accordingly.”

February 9, 2024

Meta-analysis Finds People with ADHD Twice as Likely to Self-harm

Background: 

Non-suicidal self-injury (NSSI) means intentionally hurting yourself without trying to end your life. Common examples include cutting, scratching, or burning yourself. This behavior is most common in teenagers, affecting 13-20% of adolescents. It’s also called self-harm or deliberate self-injury. 

Young people who struggle with managing emotions, act impulsively, or have mental health conditions like depression are more likely to self-harm. 

Because ADHD involves impulsivity and often occurs alongside emotional difficulties, researchers have suspected a link between ADHD and self-injury. However, previous studies have tended to be small, unrepresentative, and inconsistent, making it hard to draw clear conclusions. 

The Study: 

Researchers combined results from 14 different studies involving nearly 30,000 people to get a clearer picture. They looked at children, teenagers, and adults with ADHD from various settings—including hospitals, community programs, and general population studies. 

To be included, studies had to confirm ADHD diagnosis through professional evaluation or validated testing methods. 

Key findings 

  • About 1 in 4 people with ADHD (27%) have engaged in self-injury. This rate was similar for adults (25%) and teenagers (28%).
  • People with ADHD had more than twice the odds (2.25 times higher) of self-injury compared to people without ADHD 
  • Girls and women with ADHD were at highest risk—they had four times higher rates of self-injury than boys and men with ADHD 

Conclusion: 

The researchers concluded that roughly one in four people with ADHD have engaged in non-suicidal self-harm. The findings suggest that ADHD and self-harm share overlapping vulnerabilities. 

Overall, this meta-analysis strengthens evidence that people with ADHD face a significantly elevated risk of non-suicidal self-injury, likely reflecting overlapping challenges with impulsivity, emotional regulation, and co-occurring mental health conditions. Importantly, this does not mean self-harm is inevitable in ADHD. It does, however, highlight the need for early screening, supportive environments, and targeted mental-health care to help reduce risk and support healthier coping strategies.

March 5, 2026

Meta-analysis Identifies Resilience Factors Associated with Improved Outcomes in Children and Adolescents with ADHD

Background:

While ADHD is generally linked to negative childhood outcomes, individual variability exists. Researchers have found that factors like cognition, emotion, parenting, and social interactions can help some adversity-exposed children develop better than expected. This variability has driven extensive resilience research, which now views resilience not as a single trait, but as a combination of biological, psychological, social, and ecological processes supporting adaptation. 

The Study:

This meta-analysis sought to address several key research gaps. First, while many potential resilience factors have been identified, no previous meta-analysis has quantitatively synthesized evidence focused specifically on children with ADHD. Second, relatively little research has clarified how particular resilience factors relate to specific developmental outcomes. Third, there is currently no integrated conceptual model of resilience processes tailored to children and adolescents with ADHD. 

To keep the analysis focused and clinically relevant, the authors examined psychosocial and ecological resilience factors only. Biological factors (such as genetics or cardiovascular health) and non-modifiable demographic characteristics (such as age and sex) were excluded, as they do not readily inform interventions. The analysis also focused strictly on outcomes for children and adolescents with ADHD, excluding adult outcomes and those reported for parents or teachers. Only studies based on clinical ADHD diagnoses were included. 

In total, 28 studies involving more than 11,600 participants met the inclusion criteria. Fifteen studies were rated as high quality and 13 as fair quality; none were rated low quality. However, the evidence base was relatively thin for many analyses. Of the 50 components examined, only one included five studies, six included four studies, ten included three studies, and most (33) were based on just two studies. While some components involved large samples, most did not, meaning the findings should be viewed as suggestive rather than definitive. 

Results:

Unsurprisingly, academic skills and cognitive functioning – specifically including working memory and intelligence – were strongly associated with better educational outcomes for children and adolescents with ADHD. In contrast, social skills and proactive attitudes or behaviors showed no significant link to educational attainment

Well-being outcomes showed a different pattern. Proactive attitudes and behaviors, cognitive functioning, and parental resources were associated with small-to-moderate improvements in well-being. Emotional regulation and positive parenting or attachment, however, were not significantly related to well-being in this analysis. 

For relationship outcomes, peer relationships – especially close friendships – stood out as particularly important, showing strong associations with better relational functioning. Social skills and positive parenting or attachment were linked to moderate improvements, although positive parenting alone had no significant effect. This suggests that the observed benefit likely stemmed from parental warmth and secure parent–child attachment rather than parenting practices in isolation. Parental resources (such as parental social support) and school-based support (including student–teacher relationships) showed no significant association with relationship outcomes. 

The study also examined behavioral symptoms. Externalizing symptoms refer to outward-directed behaviors that affect others or the environment, such as aggression, defiance, impulsivity, hyperactivity, and rule-breaking. Peer relationships were linked to a modest reduction in these behaviors, while positive relationships with adults were associated with a strong reduction. In contrast, disciplinary parenting – particularly harsh punishment – was strongly associated with increased externalizing symptoms. 

Internalizing symptoms involve inward-directed distress, such as anxiety, depression, withdrawal, excessive worry, and unexplained physical complaints. Here again, positive relationships with adults were important, showing a moderate association with fewer internalizing symptoms. Emotional regulation was also linked to small-to-moderate improvements. 

Conclusion: 

Overall, the findings highlight that resilience factors tend to be closely tied to specific outcomes rather than broadly protective across domains. For example, emotional regulation was associated with lower levels of both internalizing and externalizing symptoms but showed no significant link to well-being, educational achievement, or relationship quality. This suggests that emotional regulation may play a particularly important role in protecting mental health in children with ADHD, rather than driving broader developmental gains – consistent with evidence that emotional dysregulation is a core difficulty in ADHD. 

Similarly, academic skills, social competence, and prosocial behaviors were linked mainly to their most closely related outcomes. Cognitive functioning was associated with both educational and well-being outcomes, but its impact was much stronger in education and more modest for well-being. Together, these context-specific patterns underscore the importance of designing interventions that target particular resilience factors with strategies tailored to specific developmental goals, rather than assuming that any single factor will promote resilience across all areas of life. 

Key takeaway: resilience is individual and resilience isn’t one trait; different types of support help different individuals, in different areas.

Higher Relative Fat Mass (RFM) Associated with Lower ADHD Risk in Boys but Higher ADHD Risk in Girls

Background: 

Traditional measures of obesity, like body mass index (BMI) and waist circumference, have been linked to ADHD risk — but they aren’t great at capturing where fat is actually stored in the body. A newer index called relative fat mass (RFM), which combines height and waist circumference, does a better job of estimating overall body fat and predicting metabolic risks like heart disease and metabolic syndrome. Because those conditions share some underlying biological mechanisms with ADHD, researchers wondered whether RFM might also help explain the relationship between obesity and ADHD — particularly in children. 

That question is complicated by the fact that ADHD doesn't look the same in boys and girls. Boys tend to display more hyperactive and impulsive behavior, making their ADHD easier to spot. Girls more often show inattention, which is quieter and frequently goes undiagnosed. 


The Study: 

A new study set out to test whether RFM is associated with ADHD in children, and whether that association differs between sexes. Using data from the National Health and Nutrition Examination Survey (NHANES) collected between 1999 and 2004, the researchers narrowed a large initial pool of over 31,000 participants down to 5,089 children and adolescents aged 6 to 14 who had complete data on height, waist circumference, ADHD screening, and other relevant variables. 

After adjusting for age, race/ethnicity, Poverty-Income Ratio, maternal age at delivery, maternal smoking during pregnancy, health insurance coverage, and birth weight, the results revealed a striking split along sex lines.  

In boys, higher RFM was associated with lower odds of ADHD. Compared to boys in the lowest fat-mass quartile, those in the second quartile had about 10% lower odds of ADHD, rising to over 30% lower in the third quartile and nearly 40% lower in the highest. In girls, the pattern reversed entirely. While girls in the second quartile showed similar odds to those with the lowest RFM, girls in the third and fourth quartiles had 60% to 70% greater odds of ADHD. 

Conclusion & Why This Matters:  

In recent years, the relationship between obesity and ADHD has become an increasingly important focus in pediatric neurodevelopmental research. Studies have reported higher rates of ADHD symptoms among children and adolescents with obesity compared with their non-obese peers, and difficulties with peer relationships have also been linked to increased obesity risk (Sönmez et al., 2019). From a neurobiological standpoint, both conditions may involve shared underlying mechanisms, particularly dysfunction in dopaminergic pathways.

The authors concluded that higher body fat levels appear to lower ADHD risk in boys while raising it in girls. This finding highlights why sex-specific analysis matters in ADHD research. The underlying biological reasons for this divergence, however, remain an open question and open the door for future research.