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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ADHD and Health: How Sex Differences Impact Physical Health into Adulthood

Girls are diagnosed with ADHD at less than half the rate of boys, but this gap closes significantly by adulthood. ADHD also looks different in females than in males, with distinct patterns in symptoms, development, functional impairment, economic impact, and long-term outcomes. Despite this, sex differences in how ADHD relates to physical health have been poorly studied. 

Prior research has established that both children and adults with ADHD face elevated risk for a range of physical health conditions. But that work has been hampered by small samples, retrospective designs, and limited population coverage. 

The Study

Denmark's single-payer national health system makes it possible to conduct truly population-wide research. This study drew on Danish national registers to follow more than 825,000 individuals, born between 1984 and 1995, from birth through adolescence and into young adulthood, tracking them across 13 categories of physical disease. Only individuals free of a relevant physical diagnosis at birth were included, and ADHD diagnosis was treated as something that could be acquired over time rather than a fixed characteristic. 

The Results: 

Across both sexes, people diagnosed with ADHD consistently showed higher disease risk than the general population, with cancer being the one notable exception. The absence of a meaningful cancer signal is expected, given that cancer predominantly affects older age groups than those captured in this study. 

For most other disease categories (including infectious, endocrine, metabolic, respiratory, digestive, musculoskeletal, and genitourinary diseases), elevated risk emerged in early adolescence. For the remaining categories, elevated risk was present at all ages studied. 

The magnitude of these risks was often substantial: 

  • Infectious diseases: Males aged 14–23 with ADHD faced about 20% greater risk than peers without ADHD; females in the same age group faced roughly 80% greater risk. These differences converged to around 45% above baseline beyond that age. 
  • Eye diseases: Before age 11, males with ADHD had more than twice the risk of their non-ADHD peers; females had more than five times the risk. By age 22, both sexes converged at roughly 35% above baseline. 
  • Ear diseases: Risk was more than five times higher in children with ADHD under age 7. 
  • Nervous system diseases: Risk more than doubled across all ages studied. 
  • Endocrine, nutritional, and metabolic diseases: Risk more than doubled between ages 7 and 23. 
  • Skin conditions: Risk more than doubled through age 11. 

By early adulthood, individuals with ADHD showed at least 20% greater risk across every disease category except cancer, regardless of sex. 

Sex Differences Shift With Age 

One of the study's more nuanced findings concerns how sex interacts with ADHD diagnosis over time. In the general population, females tend to have higher physical disease risk from the teenage years onward, while males show higher risk in early childhood. ADHD diagnosis disrupted these patterns unevenly, amplifying risk in some groups and age windows more than others. 

Perhaps most notably, the transition into young adulthood appeared to reduce the ADHD-associated gap between the sexes for endocrine, nutritional, and metabolic diseases (from a ninefold female-to-male disparity down to roughly 4.5-fold). The authors suggest this may reflect ADHD's influence on sex hormone activity during this developmental period. 

Takeaway 

This large, population-representative study confirms that an ADHD diagnosis is associated with meaningfully elevated risk across nearly all categories of physical disease, and that this relationship is neither uniform across sexes nor static across the lifespan. The findings underscore the need for sex-sensitive, developmentally informed approaches to the physical healthcare of people with ADHD. 

Antidepressants in Pregnancy and ADHD Risk: What a Major New Analysis Found

Antidepressants are the primary drug treatment for depressive disorders, which affect 15–20% of pregnant women. They are among the most widely prescribed medications worldwide, and their use has increased in recent decades. Understanding their reproductive safety is critical to support informed, evidence-based prescribing during pregnancy. 

A new meta-analysis sheds important light on one of the most debated concerns: whether children born to mothers who took antidepressants during pregnancy face a higher risk of ADHD. 

The Study: 

Pooling 14 studies covering more than 14 million participants, the analysis found that prenatal antidepressant exposure was associated with a 35% higher rate of ADHD in offspring compared to no exposure. A separate look at SSRIs (the most widely prescribed class of antidepressants, including Prozac and Zoloft) across 11 studies and over four million pregnancies found an even higher apparent risk (44%)  after correcting for publication bias. On the surface, these are striking numbers. 

Both associations came with an important caveat: enormous variation between individual studies, a statistical red flag suggesting the results may not reflect a true underlying effect. More tellingly, the apparent risk evaporated entirely when researchers applied a more rigorous method — comparing siblings within the same family, where one child was exposed to antidepressants in the womb, and another was not. 

This sibling-comparison design is particularly powerful because it automatically controls for factors that run in families: shared genes, household environment, parenting, and socioeconomic conditions. When those influences are held constant, the link between antidepressant exposure and ADHD disappears. The same pattern held for SSRIs specifically. 

Two other antidepressant classes, SNRIs (serotonin norepinephrine reuptake inhibitors) and tricyclics, showed no significant association in any analysis. 

“Confounding by Indication”: 

The probable driver of the initial association is what researchers call confounding by indication. The very condition being treated (depression) is itself a risk factor for ADHD in offspring, independently of any medication. Mothers with more severe depression are also more likely to be prescribed antidepressants, meaning the drug and the underlying illness are difficult to disentangle in standard analyses. Sibling studies cut through this problem cleanly. 

The Take-Away: 

The authors concluded that the association between antidepressants and ADHD risk was non-significant across all analyses designed to account for these confounding factors. This doesn’t mean antidepressants are without any reproductive considerations, but it does suggest that ADHD risk, at least, is driven by heritable and family-level factors rather than medication exposure itself. 

For clinicians and patients weighing the risks of treating or not treating depression during pregnancy, this distinction matters considerably. 

Computerized Cognitive Remediation Therapy for ADHD: A Meta-analysis

Executive functions are the mental processes that allow us to plan, adapt, and follow through. This encompasses working memory, inhibitory control, cognitive flexibility, goal-directed planning, and problem-solving. In people with ADHD, weaknesses in these areas compound the disorder's core symptoms, making it substantially harder to manage complex, real-world demands. 

Background:

Medication remains the frontline clinical response. Stimulant medications can meaningfully reduce both executive function deficits and ADHD symptoms, and are often combined with behavioral or psychological therapies for better overall outcomes.  

Medication, however, is not entirely without risk of side effects. These risks have spurred interest in new, non-pharmacological alternatives that target the same neural pathways. One of these new therapies is Computerized Cognitive Remediation Therapy (CCRT). This therapy uses digital programs delivered via computer, tablet, or smartphone that train attention, memory, and inhibitory control through structured cognitive exercises. A key feature of many CCRT platforms is adaptive difficulty: tasks adjust in real time to match the child’s current ability, keeping training both challenging and engaging. 

The Study: 

Despite this promise, the evidence base in younger populations has been limited. This meta-analysis pooled results from randomized controlled trials enrolling participants under 18 who either carried an ADHD diagnosis or scored above the threshold on a validated rating scale. Comparators included no treatment (waitlist), placebo (pharmacological or psychological), or treatment as usual. The primary outcomes (overall executive function and clinical symptom severity) were assessed via questionnaires and neuropsychological testing. Studies including participants with comorbid autism, tic disorders, epilepsy, or other psychiatric conditions were excluded. 

The findings were informative, but overall results were mixed. CCRT produced a small but statistically meaningful reduction in inattention symptoms across 13 studies (885 participants), with consistent results across individual trials and no evidence of publication bias. However, it had no detectable effect on hyperactivity and impulsivity (12 studies, 833 participants) or on total ADHD symptom burden (10 studies, 731 participants). 

The picture was more encouraging for executive function. Nine studies (500 participants) showed small overall improvements, with specific gains in working memory (454 participants), inhibitory control (428 participants), and planning (6 studies, 335 participants). Emotional control showed no significant change (5 studies, 265 participants), nor did cognitive flexibility (4 studies, 189 participants). 

The Take-Away: 

Taken together, these results are modest rather than transformative, but context matters. CCRT is low-cost, digitally scalable, and carries negligible side effects. For a population where medication often comes with a significant burden of adverse reactions, even small, reliable improvements in executive function represent a meaningful clinical option. 

The evidence positions CCRT not as a replacement for established treatments, but as a practical and well-tolerated addition to the therapeutic toolkit for children and adolescents with ADHD. 

August 5, 2026