November 1, 2021

Two nationwide population studies on opposite sides of the world confirm links between autoimmune diseases and ADHD, suggest they are from genetic co-aggregation

Both Taiwan and Sweden have universal single-payer health insurance systems that in effect track their entire national populations. With detailed health and other records on millions of individuals, with no significant exclusions, one can essentially eliminate sampling error, and also explore how associations vary by degree of familial/genetic relationship.

A Taiwanese research team used the Taiwan National Health Insurance Research Database to follow 708,517 family triads (father-mother-child) from 2001 through 2011. That's a total of over 2.1 million persons. The database covers over 99% of Taiwan's population.

Noting that previous studies had found links between maternal autoimmune diseases and ADHD in their offspring and that research on associations with paternal autoimmune diseases had been inconclusive, they were particularly interested in exploring the latter.

Children born from 2001 through 2008 were enrolled in the study. The investigators then noted the presence or absence of any autoimmune disease in their parents from 1996 through childbirth.

In Taiwan, expert panels review diagnostic information of severe systemic autoimmune diseases to confirm the diagnosis. Once confirmed, patient co-payments are waived. ADHD diagnoses are by board-certified psychiatrists.

To reduce the effect of confounding variables, adjustments were made for family demographic data (income level and residence), parental ages, parental mental disorders, and sex of children.

The presence of any maternal autoimmune diseases was associated with a 60% greater risk of ADHD in offspring. The risk was especially elevated for inflammatory bowel diseases (2.4 times the risk) and ankylosing spondylitis (twice the risk).

The presence of any paternal autoimmune diseases was also associated with an elevated risk of ADHD in offspring, although only about half as much as for maternal autoimmune diseases, with a 33% greater risk overall. The association was especially pronounced for psoriasis and ankylosing spondylitis, both doubling the risk of ADHD in offspring.

Meanwhile, half a world away, a joint Swedish, Norwegian, and U.S. team used the Swedish national registries to dig further into these associations. They did this by examining data not only from mothers and fathers, but from full siblings, aunts, uncles, and cousins as well, to probe genetic links.

The team used the Swedish registers to identify 5,178,225 individuals born in Sweden between 1960 and 2010 for whom the identity of the biological mother was known, excluding all who died or emigrated before age 10. They then used the registers to identify the aforementioned relatives.

The researchers only included autoimmune diseases with at least two thousand diagnosed individuals in the cohort, to avoid small sample effects.

They adjusted for sex and year of birth, but not "for another covariate that is often adjusted for (e.g. maternal education, family income, parental psychiatric disorder, parental AD [autoimmune disease] as these are likely not true confounders of the association between ADHD and ADD, but may rather represent either mediator between ADHD and AD's, or proxies of ADHD and/or AD risk or alternatively proxies for the associations we aim to measure."

The team found statistically significant associations between ADHD and autoimmune diseases in all categories of relatives. Mothers of children with ADHD were 29% more likely to have an autoimmune disease than those of typically developing children; fathers were 14% more likely to have an autoimmune disease; full siblings 19% more likely; aunts 12% more likely; uncles 7% more likely; and cousins 4% more likely.

Quantitative genetic modeling produced a significant genetic correlation, but no significant environmental correlation. Genetic correlation explained most, if not all, the covariance between ADHD and any autoimmune disease.

The authors concluded, "ADHD was to some degree more strongly associated with maternal than paternal AD's, but by using aunts and uncles in a genetically informative study design, we demonstrate that this difference cannot be readily explained by AD-mediated maternal effects. Quantitative genetic modeling further indicates that the familial co-aggregation of ADHD and ADs is partly due to shared genetic factors. In addition, biological aunts, uncles, and cousins must be assumed to share the little environment with the index individuals, in further support of shared genetic factors underlying the familial co-aggregation. Moreover, both epidemiological and molecular genetics studies have demonstrated positive genetic correlations between ADHD and ADs, in agreement with our findings."

The authors emphasize that these results do not warrant screening for autoimmune diseases among asymptomatic individuals with ADHD.

Tor-Arne Hegvik, Qi Chen, Ralf Kuja-Halkola, Kari Klungsøyr, Agnieszka Butwicka, Paul Lichtenstein, Catarina Almqvist, Stephen V Faraone, Jan Haavik, Henrik Larsson. "Familial co-aggregation of attention-deficit/hyperactivity disorder and autoimmune diseases: a cohort study based on Swedish population-wide registers," International Journal of epidemiology (2021), published online, https://doi.org/10.1093/ije/dyab151.

Hsuan Lee, Ju-Wei Hsu, Shih-Jen Tsai, Kai-Lin Huang, Ya-MeiBai, Tung-Png Su, Tzeng-Ji Chen, Mu-Hong Chen, "Risk of attention deficit hyperactivity and autism spectrum disorders among the children of parents with autoimmune diseases: a nationwide birth cohort study," European Child &Adolescent Psychiatry (2021), published online, https://doi.org/10.1007/s00787-021-01860-0.

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New Study Examines ADHD Stimulant Use and Substance Use Risks Among Adolescents

U.S. Study Finds No Increased Non-Medical Use Among Those Prescribed Stimulants as Adolescents, but Finds Other Links

A recent U.S. study challenges assumptions about the link between prescription stimulant use for ADHD and later substance abuse. Adolescents who used prescription stimulants under a physician’s supervision did not exhibit increased rates of non-medical stimulant use or cocaine use as they transitioned into young adulthood. However, other factors, like binge drinking and cannabis use, showed significant associations with later substance misuse, suggesting that the landscape of risk is more complex than previously understood.

Stimulants and ADHD: Understanding the Risks

Prescription stimulants are considered one of the most effective treatments for ADHD. While these medications can significantly improve focus and behavior, concerns have persisted that using stimulants during adolescence might predispose individuals to substance use disorder (SUD). Some theories suggest that early exposure to stimulants could increase the likelihood of cocaine use, as both substances affect the brain's dopamine pathways similarly.

Yet, previous research often lacked large, longitudinal studies focusing on adolescents with ADHD who had never been treated with stimulants. To fill this gap, a research team followed a nationally representative cohort of 11,905 high school seniors (12th graders, mostly aged 18) for six years, tracking their substance use behaviors.

Study Design: Following the Participants

At the start of the study, participants completed surveys regarding their ADHD treatment history—whether they had used stimulant therapy, non-stimulant therapy, or no medication at all. This formed three groups:

  • Adolescents treated with stimulant therapy for ADHD
  • Adolescents treated with non-stimulant therapy for ADHD (ADHD controls)
  • Adolescents with no history of ADHD treatment (non-ADHD controls)

Participants then completed follow-up surveys every two years, reporting on their use of substances like prescription stimulants and cocaine, as well as their engagement in behaviors like binge drinking and cannabis use.

Key Findings: No Direct Link to Non-medical Stimulant or Cocaine Use

The study found no significant differences in the rates of non-medical stimulant use or cocaine use among the three groups. Adolescents who had been prescribed stimulant medications were not more likely to misuse prescription stimulants or cocaine as young adults than those who had not received such medications.

However, other behaviors at age 18 showed strong associations with later substance use:

  • Binge drinking during late adolescence was linked to an 80% increase in the likelihood of subsequent nonmedical prescription stimulant use and cocaine use.
  • Nonmedical use of prescription opioids at age 18 increased the odds of later nonmedical stimulant use by 50% and of cocaine use by two-thirds.
  • Cannabis use by age 18 more than tripled the likelihood of later non-medical stimulant use and increased the odds of subsequent cocaine use sixfold.

Clinical Implications

The study’s findings have important implications for both clinicians and families managing ADHD. Although ADHD is associated with an increased risk of SUD, the researchers observed no higher risk of nonmedical stimulant use among adolescents who had taken stimulant therapy compared to those who hadn’t. Additionally, there was no evidence that stimulant medications posed a greater risk than non-stimulant medications for subsequent misuse.

The findings also highlight the need for more robust screening for alcohol and other drug use among adolescents. As the study notes, current guidelines do not recommend routine screening for substance misuse in adolescents due to limited evidence. However, given the associations found between binge drinking, cannabis use, and later substance misuse, such preventive measures could play a key role in reducing risks during this vulnerable period of development.

Ultimately, the study sheds light on the multifaceted nature of substance use risks in adolescents and young adults, suggesting that while prescription stimulant use for ADHD under medical supervision may not directly contribute to substance abuse, the broader context of an adolescent’s behaviors and environment is crucial in shaping future outcomes.

October 17, 2024

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

News Tuesday Study! Understanding ADHD in Older Adults: An Overlooked Concern

60% to 90% of youth with ADHD continue to have symptoms as adults. In older adults, about 2.5% are believed to have ADHD, but it often goes unnoticed because research is limited and current diagnosis methods are based mostly on studies of young people.

Our commentary discusses key points about ADHD in older adults.  Although 2 to 3 percent of older adults have ADHD when using proper diagnostic tools, only 0.23% are diagnosed in medical records. This shows that ADHD is greatly underdiagnosed in older adults. Even worse, less than 40% of those who are diagnosed receive any treatment, which highlights the need for doctors to be better educated about ADHD in this age group. Current ways of diagnosing ADHD need to be improved for people over 50. Also, there isn’t much research on ADHD medications for people over 60, with most studies excluding them, which raises concerns about how safe and effective these treatments are for older adults, especially since stimulant medications can affect the heart.

There are also biases among doctors that make it harder to diagnose and treat ADHD in older adults. Many doctors aren’t trained to recognize ADHD in this age group and still see it as a condition that only affects young people. Some think that if a person hasn’t been treated for ADHD by this stage in life, they don’t need treatment now. But this ignores the fact that untreated ADHD can cause lifelong struggles and reduce the person’s quality of life. Some doctors are also worried about the risks of ADHD medications for older patients, even though research shows that these medications are usually safe when properly monitored.

Diagnosing ADHD in older adults can be tricky because its symptoms can look similar to other conditions, like mild cognitive impairment or dementia. This makes it important for doctors to do a thorough assessment that looks at medical, psychiatric, and psychological factors. Since older adults often have other health issues, it’s crucial for doctors to tell the difference between ADHD symptoms and those caused by other conditions.

In the end, we need more awareness, training, and research on ADHD in older adults. Doctors need to push past biases and consider the benefits of treating ADHD in this age group, carefully weighing the risks and rewards. As the population of older adults grows, so does the need for studies and guidelines to provide better care for older people with ADHD. Filling these gaps will ensure that older adults with ADHD get the attention and treatment they need.

October 8, 2024