November 10, 2023

How do psychiatric comorbidities affect risk of premature death among children and adults with ADHD?

The Nordic countries maintain detailed registers of their inhabitants. This enables researchers to examine patterns over entire nations. An international research team used the Swedish national registers for a prospective cohort study of 2,675,615 persons in the Medical Birth Register born in Sweden over a 27-year period from January 1, 1983, through December 31, 2009. Follow-up was completed in December 2013, with the oldest cohort member aged 31. The mean age at study entry was 6, and the mean at follow-up was 11.

Using personal identification numbers, researchers were able to cross-reference with the National Patient Register and the National Drug Register. From this, they determined that 86,670 members of the cohort (3.2 percent) had ADHD, based either on records of clinical diagnosis or of prescription of ADHD drugs. Psychiatric comorbidities were likewise identified in the National Patient Register.

These comorbidities were significantly more prevalent in the ADHD population than in the rest of the cohort. For example, whereas only 2.2% of the non-ADHD group was diagnosed with substance use disorder (SUD), 13.3% of the ADHD group also had SUD, a six-fold difference. For depression, it was a seven-fold difference, for schizophrenia a nine-fold difference.

The ADHD group had a significantly higher risk of premature death from all causes than the non-ADHD group, with an adjusted hazard ratio (HR) of 3.94 (95% CI 3.51-4.43). Unintentional injury(36%) and suicide (31%) were the leading causes of death in the ADHD group. Those with ADHD were more than eight times more likely to die by suicide than non-ADHD individuals, and roughly four times more likely to die from unintentional injury.

The vast majority of the increased risk appears to be associated with comorbid psychiatric conditions. Those with ADHD but no diagnosed comorbidities had an adjusted HR of 1.41 (95% CI 1.01-1.97). With a single comorbidity, the HR more than doubled to 3.71 (95% CI 2.88-4.78). With four or more comorbidities, it rose to a staggering 25.22 (95% CI 19.6-32.46).

The comorbid condition with the greatest impact was SUD, which increased the risk eight-fold by comparison with those with only ADHD (HR = 8.01, 95% CI 6.16-10.41). Anxiety disorder, schizophrenia, and personality disorder increased the risk about fourfold. Bipolar disorder, depression, and eating disorder increased risk by roughly two and a half times.

Co variate analysis helped tease out what portion of the risk was associated with ADHD alone versus comorbid conditions. Adjusting for the year of birth, sex, birth weight, maternal age at birth, parental educational level, and parental employment status, those with ADHD (including comorbid conditions) were 2.7 times more likely to prematurely die of natural causes than those without. Adjusting for comorbid psychiatric conditions completely eliminated the risk from ADHD alone (HR = 1.01, 95% CI .72-1.42).

Likewise, those with ADHD (including comorbid conditions) were six times as likely to die of unnatural causes. Adjusting for early-onset comorbid disorders(such as conduct disorders, autism spectrum disorder, and intellectual disability) only modestly reduced the HR to 5.3, but further adjusting for later-onset comorbid disorders (including substance use disorder, depressive disorder, bipolar disorder, anxiety disorder, schizophrenia, personality disorder, and eating disorders) reduced the HR to 1.57 (95% CI 1.35-1.83), and reduced it to insignificance in the case of suicide (HR = 1.13, 95% CI.88-1.45).

Summing up, the lion’s share of the greater risk of premature death in persons with ADHD is attributable to psychiatric comorbidities. Nevertheless, those with ADHD alone still face a 40 percent greater risk than those without ADHD.

The study did not examine effects of ADHD medication, which the authors state “should be analyzed because of documented potential benefits on ADHD symptoms and comorbid disorders.”

The authors concluded, “Among adults, early-onset psychiatric comorbidity contributed substantially to the premature mortality risks due to natural causes. On the other hand, later-onset psychiatric comorbidity, especially SUD, explained a substantial part of the risk for unnatural deaths, including all the risk of suicide deaths and most of the deaths due to unintentional injuries. These results suggest that overall health conditions and risk of psychiatric comorbidity should be evaluated clinically to identify high-risk groups among individuals with ADHD.”

Shihua Sun, MD; Ralf Kuja-Halkola, Ph.D.; Stephen V. Faraone, Ph.D.; Brian M. D’Onofrio, Ph.D.; Søren Dalsgaard, Ph.D.; ZhengChang, Ph.D.; Henrik Larsson, Ph.D., “Association of Psychiatric Comorbidity With the Risk of Premature Death Among Children and Adults With Attention-Deficit/Hyperactivity Disorder,” JAMA Psychiatry doi:10.1001/jamapsychiatry.2019.1944Published online August 7, 2019.

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Saudi Study Illustrates Pitfalls of Network Meta-analysis When Evidence Base is Thin

Treatment guidelines for childhood ADHD recommend medications as the first-line treatment for most youth with ADHD. Still, concerns about side effects and long-term outcomes have increased interest in non-pharmacological approaches. Researchers at Saudi Arabian Armed Forces hospitals recently conducted a network meta-analysis comparing several interventions, including mindfulness-based therapy, cognitive behavioral therapy, behavioral parent training, neurofeedback, yoga, virtual reality programs, and digital working memory training. 

Although the authors aimed to “provide a rigorous methodological approach to combine evidence from multiple treatment comparisons,” the study illustrates several pitfalls that arise when network meta-analysis is applied to a thin and heterogeneous evidence base. 

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What Network Meta-analysis Can and Cannot Do:

Network meta-analysis extends conventional meta-analysis by combining: 

  • Direct comparisons (treatment A vs. treatment B tested in clinical trials), and 
  • Indirect comparisons (A vs. B inferred through a common comparator such as placebo or usual care). 

When the evidence network is large and well-connected, this approach can provide useful estimates of comparative effectiveness among many treatments. 

This method is not always best, however, as many networks are sparse. This is especially true in areas such as complementary or behavioral therapies. In sparse networks, estimates rely heavily on indirect comparisons, and single studies can exert disproportionate influence over the results. 

Conventional meta-analysis focuses on heterogeneity, meaning differences in results across studies within the same comparison. 

Network meta-analysis must additionally evaluate consistency, whether the direct and indirect evidence agree. 

However, when comparisons are supported by only one or two studies and the network is weakly connected, statistical tests for heterogeneity and consistency have very little power. In practice, this means the analysis often cannot detect problems even if they are present. 

Sparse networks also make publication bias difficult to evaluate. This concern is particularly relevant in fields dominated by small trials and emerging therapies. 

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Why Such Treatment Rankings Are Appealing, but Potentially Problematic:

Many network meta-analyses summarize results using SUCRA, which estimates the probability that each treatment ranks best. 

SUCRA, or Surface Under the Cumulative Ranking, is a key statistical metric in network meta-analyses. It is used to rank treatments by efficacy or safety. This is achieved by summarizing the probabilities of a treatment's rank into a single percentage, where a higher SUCRA value indicates a superior treatment. Ultimately, SUCRA helps pinpoint the most effective intervention among the ones compared. 

Again, in well-supported networks, SUCRA can provide a useful summary of comparative effectiveness. But in sparse networks, rankings can create an illusion of precision, because treatments supported by a single small study may appear highly ranked simply due to random variation. 

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What Did this New Network Meta-analysis Study?

The study includes 16 trials with a total of 806 participants. But the structure of the evidence network is far weaker than this headline number suggests. 

Based on the underlying studies: 

  • Six interventions are supported by a single trial each (digital cognitive mindfulness training, BrainFit, neurofeedback, online mindfulness-based program, cognitive behavioral therapy, and working-memory training) 
  • Three interventions are supported by two trials each 
  • Only one intervention is supported by three trials (family mindfulness-based therapy) 

This produces a very thin network, in which several interventions rely entirely on single studies. 

Another challenge is that the included trials measure different outcomes. Some evaluate ADHD symptom severity, while others measure parental stress. 

When studies use different outcome scales, meta-analysis typically relies on standardized measures such as the standardized mean difference to allow comparisons across studies. However, the analysis reports only mean-average differences, making it difficult to interpret the relative effect sizes. 

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Study Issues (including Limited Evidence and Risk of Bias): 

The intervention supported by the largest number of studies (family mindfulness-based therapy) was one of the two approaches reported as producing statistically significant results. The other was BrainFit, which is supported by only a single previous trial. 

Despite this limited evidence base, the study ranks interventions using SUCRA: 

  • Family MBT: 92% probability of being best 
  • Behavioral parent training (BPT): 65% 
  • Online mindfulness program: 49% 
  • Cognitive behavioral therapy: 48% 
  • Yoga: 39% 

Notably, none of the runner-up interventions demonstrated statistically significant efficacy. 

The authors acknowledge methodological limitations in the included studies: 

“Blinding of participants and personnel (performance bias) exhibited notable concerns, as blinding for active treatment was not applicable in most studies.” 

Such limitations are common in behavioral intervention trials, but they further increase uncertainty in already small evidence networks. 

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Conclusions:

The study ultimately concludes: 

“This network meta-analysis supports MBT and BPT as effective non-pharmacological treatments for ADHD.” 

However, the evidence underlying these claims is limited. Some analyses rely on very small numbers of studies and participants, and the network structure depends heavily on indirect comparisons. 

Network meta-analysis can be a powerful tool when applied to a large, consistent, and well-connected body of evidence. When the evidence base is sparse, however, the resulting rankings and comparisons may appear statistically sophisticated while resting on a fragile evidentiary foundation.

April 17, 2026

Finding Order in the Complexity of ADHD: A Brain Imaging Study Identifies Three Neurobiological Subtypes

ADHD is one of the most common neurodevelopmental disorders in children, yet anyone familiar with this disorder, from clinicians and researchers to parents and patients, knows how differently it can manifest from one individual to the next. One person diagnosed with ADHD may primarily struggle with focus and staying on-task; another may find it nearly impossible to regulate their impulses or even start tasks; a third may frequently find themselves frozen with overwhelm and subject to emotional reactivity…

These are not just variations in severity; they may reflect genuinely different patterns of brain organization.

Our current diagnostic system groups all of these presentations under a single label (ADHD), with three behavioral subtypes (Hyperactive, Inattentive, and Combined) defined by symptom checklists. This framework has real clinical value of course, but it was built from behavioral observation rather than neurobiology, and may leave room for substantial heterogeneity to remain unexplained. In a new study, published in JAMA Psychiatry, researchers asked whether it’s possible to identify distinct neurobiologically subgroups within ADHD by analyzing patterns of brain structure, and whether those subgroups would map onto meaningful clinical differences.

How the Brain Was Analyzed

Researchers analyzed structural MRI scans from 446 children with ADHD and 708 typically-developing children across multiple research sites. From each scan, they constructed a morphometric similarity network; that is, a map of how different brain regions resemble one another in their structural properties. These networks reflect underlying biological organization, including shared patterns of cellular architecture and gene expression across brain regions.

From each individual's network, the research team calculated three properties that capture how each brain region functions within the broader network: how many connections it has, how efficiently it communicates with other regions, and how well it bridges different functional communities in the brain. Regions that score highly on these measures are sometimes called "hubs" and they play particularly influential roles in how information is integrated across the brain.

Rather than comparing the ADHD group to controls as a whole and looking for average differences, they used a normative modeling approach. This works similarly to a growth chart in pediatric medicine: instead of asking whether a child is above or below the group average, it asks how much a given child deviates from the expected range for their age and sex. This allows for individual variation across the ADHD group rather than flattening it into a single average profile.

The team then applied a data-driven clustering algorithm to these individual deviation profiles, allowing the data to reveal whether subgroups of children with ADHD shared similar patterns of brain network atypicality, without using any clinical symptom information to guide the clustering.

The Results:

Three stable, reproducible subtypes emerged from this analysis.

The first subtype was characterized by the most widespread differences from the normative range, particularly in regions connecting the medial prefrontal cortex to the pallidum (a deep brain structure involved in motivation and emotional regulation). Children in this group had the highest levels of both inattention and hyperactivity/impulsivity, and over a four-year follow-up period showed more persistent difficulties with emotional self-regulation than the other groups. They also had a higher rate of mood disorder comorbidity during follow-up, though this difference did not reach statistical significance given the sample size. The brain deviation patterns of this subtype showed correspondence with the spatial distributions of several neurotransmitter systems, including serotonin, dopamine, and acetylcholine, all of which have been previously implicated in ADHD pathophysiology.

The second subtype showed alterations concentrated in the anterior cingulate cortex and pallidum, a circuit involved in action control and response selection. This subtype had a predominantly hyperactive/impulsive profile, and its brain deviation patterns were associated with glutamate and cannabinoid receptor distributions.

The third subtype showed more focal differences in the superior frontal gyrus, a region involved in sustained attention. This subtype had a predominantly inattentive profile, with brain patterns linked to a specific serotonin receptor subtype.

A particularly important observation was that these brain-derived groupings aligned with clinically meaningful symptom differences, even though no symptom information was used in the clustering process. The fact that an analysis of brain structure alone arrived at groupings that correspond to recognizable clinical patterns is meaningful evidence that these subtypes reflect genuine neurobiological differences rather than statistical noise.

Replication in an Independent Sample

Scientific findings are only as trustworthy as their ability to replicate. The research team tested this clustering model in an entirely independent cohort of 554 children with ADHD from the Healthy Brain Network, a large, publicly available dataset collected under different conditions. The three subtypes were successfully identified in this new sample, with strong correlations between the brain deviation patterns observed in the original and validation cohorts. Differences in hyperactivity/impulsivity across subtypes were consistent with the discovery cohort, providing meaningful external validation of the approach.

What This Does and Doesn't Mean

It is important to be clear about what these findings do and do not imply. This study does not establish that these three subtypes are categorically distinct biological entities with sharp boundaries. They probably represent distinguishable regions along an underlying continuum of neurobiological variation. The neurochemical associations reported are exploratory and spatial in nature; they describe correspondences between brain deviation maps and neurotransmitter receptor density maps derived from separate imaging studies, and do not directly establish that any particular neurotransmitter system is altered in each subtype, nor do they currently inform treatment decisions.

The samples were not entirely medication-naive, and the strict comorbidity exclusion criteria may limit how well these findings generalize to typical clinical populations where comorbidities are the rule rather than the exception. All data came from research sites in the United States and China, and broader generalizability remains to be established.

What the study does demonstrate is that structured neurobiological heterogeneity exists within the ADHD diagnosis, that it can be reliably detected using brain imaging and data-driven methods, and that it aligns with meaningful clinical differences. The subtype defined by the most extensive brain network differences and the most severe, persistent clinical profile may be of particular importance, representing a group that could benefit most from early identification and targeted support.

The longer-term goal of this line of research is to move toward a more biologically grounded understanding of ADHD that complements existing diagnostic approaches and that may ultimately help guide more individualized treatment decisions. That goal, for now, remains a research ambition rather than a clinical reality, but this study takes a meaningful step in that direction.    

March 31, 2026

ADHD and Blood Pressure Medication: Why Staying on Treatment Is Harder, and What Might Help

Managing high blood pressure requires more than just getting a prescription; it means taking medication consistently, day after day, often for years. For people with ADHD, that kind of routine can be genuinely difficult. In our new study, published in BMC Medicine, we set out to understand just how much ADHD affects whether people stick with their blood pressure medication, and whether ADHD treatment itself might make a difference.

Why This Question Matters

Hypertension affects nearly a third of adults worldwide and is one of the leading drivers of heart disease and stroke. At the same time, ADHD, long thought of as a childhood disorder, affects around 2.5% of adults and is increasingly recognized as a risk factor for cardiovascular problems, including high blood pressure. Yet no large-scale study had ever examined whether having ADHD affects how well people follow through with their blood pressure treatment. We wanted to fill that gap.

What We Did

We analyzed health records from over 12 million adults across seven countries, Australia, Denmark, the Netherlands, Norway, Sweden, the UK, and the US, who had started antihypertensive (blood pressure-lowering) medication between 2010 and 2020. About 320,000 of them had ADHD. We tracked two things: whether they stopped their blood pressure medication entirely within five years, and whether they were taking it consistently enough (covering at least 80% of days) over one, two, and five years of follow-up.

What We Found

Across nearly all countries, adults with ADHD were more likely to stop their blood pressure medication and less likely to take it consistently. Overall, those with ADHD had about a 14% higher rate of discontinuing treatment within five years, and were 45% more likely to have poor adherence in the first year, a gap that widened to 64% by the five-year mark. These patterns were most pronounced in middle-aged and older adults.

Interestingly, young adults with ADHD were actually slightly less likely to discontinue treatment than their peers without ADHD, a finding we think may reflect the fact that younger people with ADHD are often more actively engaged with healthcare systems, especially given the cardiovascular monitoring that comes with ADHD medication use.

Perhaps the most encouraging finding was this: among people with ADHD who were also taking ADHD medication, adherence to blood pressure treatment was substantially better. Those on ADHD medication were about 38% less likely to have poor adherence at one year, and nearly 50% less likely at five years. While we can't establish causation from this type of study, one plausible explanation is that treating ADHD, reducing inattention and impulsivity, makes it easier to maintain the routines that consistent medication use requires. It's also possible that people on ADHD medication simply have more regular contact with healthcare providers, which keeps other health problems better monitored and managed.

What This Means in Practice

The core ADHD symptoms of inattention and poor organization are precisely the traits that make long-term medication adherence difficult. Add in the complexity of managing multiple disorders and medications, and it's easy to see why people with ADHD face extra challenges. Our findings suggest that clinicians treating adults with ADHD for cardiovascular disorders should be aware of these challenges and consider tailored support strategies, things like regular follow-up appointments, patient education, and tools that help with routine and organization.

There's also a broader message here about the potential ripple effects of treating ADHD well. Supporting someone in managing their ADHD may not just improve their attention and daily functioning; it may also help them take better care of their physical health, including disorders as serious as hypertension.

Future research should explore which specific support strategies are most effective, and whether these findings hold in lower- and middle-income countries where the data don't yet exist.