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Most previous studies of suicide and self-harm risk among persons with ADHD have focused on adolescents and adults. They’ve also tended to be cross-sectional, analyzing data from a population at a specific point in time. 

An Australian study team took a different approach, conducting a before-and-after study through the birth cohort of the Longitudinal Study of Australian Children (LSAC), comprising 5,107 children who have been followed up every two years since birth. 

The diagnosis of ADHD was based on parents reporting that their child had received a diagnosis of ADHD at or before age ten.  

Suicide and self-harm were defined as children’s self-report at age 14 of any thought or attempt of suicide and self-harm respectively over the past year. 

The team adjusted for the following confounders: socioeconomic status, birth weight, ADHD medication history, maternal education level, maternal age at birth, experience in bullying victimization at age 12, and depression score based on Short Mood and Feelings Questionnaire (SMFQ). 

Of the 5,107 participants, 3,696 had all the valid data required for analysis and were included in the final cohort. Of these, 3.6% were diagnosed with ADHD by age 10. 

With diagnosis of ADHD at age 10 and all other factors held constant: 

• The odds of suicidal thought, plan, or attempt at age 14 increased elevenfold. This was twice as pronounced among boys as among girls. 

• The odds of self-harm at age 14 increased 25-fold. This was more than three times as pronounced among boys as among girls. 

Both depression and exposure to bullying were statistically significant mediators for the relationship. Nevertheless, depression and exposure to bullying each accounted for well under 10% of the overall effect. 

Neither socioeconomic status nor maternal factors had any significant mediating effect on outcomes. 

Conclusion:

The authors concluded, “This study provides compelling evidence that children diagnosed with ADHD at the age of 10 years face significantly elevated risks of experiencing suicidal thoughts, planning, or attempts, as well as self-harm, by the age of 14 years, which underscores the critical importance of recognizing and addressing these heightened risks in children with ADHD.” 

While factors like depression and bullying contribute, ADHD itself remains a key risk factor. Early intervention and strong mental health support are crucial to protecting these children’s well-being.

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Noting that “Recent research has demonstrated that some gut bacteria can affect the nervous system,” and speculating that “dysregulation in the gut microbiota may increase the incidence of ADHD by overproducing reactive oxygen and nitrogen species, thereby causing neuroinflammation and oxidative stress”, a Taiwanese study team decided to explore whether early-life use of antibiotics – in the first two years – is associated with increased risk of subsequent diagnosis of ADHD. 

Because Taiwan has a single-payer national health insurance system that covers 99.8% of the island’s population, they were able to use the system’s National Health Insurance Research Database (NHIRD) and Maternal and Child Health Database (TMCHD) to include all 1.6 million children born between 2004 and 2012. 

Of these, a little over 1.1 million were given antibiotics before turning two years old, and just over 460,000 were not given antibiotics in the same time frame. 

The mean follow-up period for records of subsequent ADHD diagnoses was seven years. 

The team adjusted for confounding variables: sex, gestational age at birth (weeks), and birth weight (grams) of the children, and age at birth (years), insurance amount (New Taiwan Dollar (TWD)), insurance location, method of delivery, comorbidities, and medication used during pregnancy. 

With these adjustments, early-life antibiotics use was associated with a 12% increase in likelihood of being subsequently diagnosed with ADHD. 

However, looking at the effects of antibiotics as an undifferentiated grouping turned out to be misleading, because the association was limited to only some classes of antibiotics.  

Penicillins were associated with a 22% increase in risk of subsequent ADHD diagnosis, cephalosporins with a 10% increase.  

On the other hand, there was absolutely no such association for tetracyclines, macrolides, and quinolones. 

The Take-Away: 

This study found that children in Taiwan who took certain types of antibiotics before age 2 had a slightly higher risk of developing ADHD later in life.  More work is needed to determine if this finding is due to unmeasured confounding before a causal link can be concluded.

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Background: 

Noting that “the results of previous investigations into the therapeutic benefits of probiotics in the treatment of ADHD symptoms remain inconsistent,” a Taiwanese study team conducted a systematic search of the peer-reviewed medical literature to perform a meta-analysis. 

The Study:

The team identified seven randomized controlled trials (RCTs) that met criteria for inclusion: focusing on children and adolescents under 18, with ADHD diagnoses, comparing probiotic interventions with placebo, and using standardized behavioral rating scales to assess ADHD symptoms. 

Meta-analysis of these seven RCTs with a combined total of 342 participants found no significant improvement in ADHD symptoms. In fact, six of the seven RCTs clustered tightly around zero effect, while the seventh – a small sample (38) outlier – reported a very large effect size improvement.  

Meta-analysis of the three RCTs with a combined 154 individuals that used probiotics with single strains of microorganisms showed absolutely no improvement in ADHD symptoms with no between-study variation (heterogeneity). 

Meta-analysis of the four RCTs with a total of 188 participants that used multiple strains pointed to a medium – but statistically nonsignificant – effect size improvement, with high heterogeneity. Removing the previously mentioned outlier RCT collapsed the effect size to zero. 

Two of the RCTs (with 72 total individuals), including the outlier, offered probiotics in conjunction with methylphenidate treatment. Meta-analysis of the other five RCTs with 270 persons that were structured around pure supplementation yielded absolutely no improvement in ADHD symptoms with no heterogeneity. 

Meta-analyses of the four RCTs with a combined total of 238 participants that examined ADHD subtypes reported no effect on either inattention symptoms or hyperactivity/impulsivity symptoms. 

Trivially, given the lack of efficacy, probiotic regimens were tolerated as well as placebo. 

The Take-Away: 

Ultimately, this meta-analysis found no evidence that probiotics improve ADHD symptoms in children and adolescents. Across seven randomized controlled trials, results consistently showed no significant benefit compared to a placebo. While probiotics were well-tolerated, they did not meaningfully impact inattention, hyperactivity, or impulsivity. These findings suggest that probiotics, whether single or multi-strain, are not an effective treatment for ADHD.

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Background: 

Noting that “Previous research has demonstrated that attention significantly influences various domains such as language, literacy, and mathematics, making it a crucial determinant of academic achievement,” an international study team performed a comprehensive search of the peer-reviewed medical literature for studies evaluating effects of physical activity on attention. 

The Study:

The team’s meta-analysis of ten studies with a combined total of 474 participants found moderate reductions in attention problems following physical activity. They found no significant evidence of publication bias, but there was considerable variation in outcomes between studies (heterogeneity). 

To tease out the reasons for this variability, the team looked at specific attributes of the physical activity regimens used in the studies. 

The seven studies with 168 participants that involved mentally engaging physical activity reported large reductions in attention problems, whereas the three studies with 306 persons that used aerobic exercise found no reduction whatsoever. Heterogeneity in the former was reduced, in the latter all but disappearing. 

Comparing studies with other interventions as control groups (6 studies, 393 participants) with those with no intervention as control (4 studies, 81 participants), the former reported only small improvements in attention problems, while the latter reported large improvements. 

Duration of physical activity made little difference. The four studies with physical activity of an hour or more reported better outcomes than the six with less than an hour, but the difference was not significant. 

Greater frequency did make a difference, but in a counterintuitive way. The seven studies with one or two physical activity interventions per week (162 participants) reported large reductions in attention problems, whereas the three studies with three or more interventions per week (312 participants) showed no improvement. 

Conclusion:

The authors concluded, “Our study suggests that cognitively engaging exercise is more effective in improving attention problems in school-aged children with ADHD.” Moreover, “the benefits of improved attention in school-age children with ADHD are not necessarily positively correlated with higher frequency and longer duration of physical activity.”  Also keep in mind that exercise, while important for all children, should not replace medical and psychological treatments for the disorder.

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The National Health Interview Survey (NHIS) is conducted annually by the National Center for Health Statistics at the Centers for Disease Control and Prevention. The NHIS is done primarily through face-to-face computer-assisted interviews in the homes of respondents. But telephone interviews are substituted on request, or where travel distances make in-home visits impractical.  

For each interviewed family, only one sample child is randomly selected by a computer program.  

The total number of households with a child or adolescent aged 3-17 for the years 2018 through 2021 was 26,422. 

Based on responses from family members, 9.5% of the children and adolescents randomly surveyed throughout the United States had ADHD.  

This proportion varied significantly based on age, rising from 1.5% for ages 3-5 to 9.6% for ages 6-11 and to 13.4% for ages 12-17. 

There was an almost two-to-one gap between the 12.4% prevalence among males and the 6.6% prevalence among females. 

There was significant variation by race/ethnicity. While rates among non-Hispanic whites (11.1%) and non-Hispanic blacks (10.5%) did not differ significantly, these two groups differed significantly from Hispanics (7.2%) and Others (6.6%). 

There were no significant variations in ADHD prevalence based on highest education level of family members. 

But family income had a significant relationship with ADHD prevalence, especially at lower incomes. For family incomes under the poverty line, the prevalence was 12.7%. That dropped to 10.3% for family incomes above the poverty level but less than twice that level. For all others it dropped further to about 8.5%. Although that might seem like poverty causes ADHD, we cannot draw that conclusion.  Other data indicate that adults with ADHD have lower incomes.  That would lead to more ADHD in kids from lower income families.

There was also significant geographic variation in reported prevalence rates. It was highest in the South, at 11.3%, then the Midwest at 10%, the Northeast at 9.1%, with a jump down to 6.9% in the West. 

Overall ADHD prevalence did not vary significantly by year over the four years covered by this study. 

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Study Conclusion:

This study highlights a consistently high prevalence of developmental disabilities among U.S. children and adolescents, with notable increases in other developmental delays and co-occurring learning and intellectual disabilities from 2018 to 2021. While the overall prevalence remained stable, these findings emphasize the need for continued research into potential risk factors and targeted interventions to address developmental challenges in youth.

It is also important to note that this study assessed the prevalence of ADHD being diagnosed by healthcare professionals.  Due to variations in healthcare accessibility across the country, the true prevalence of ADHD may differ still.

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Background:

An international research team used the nationally representative 2020–2021 U.S. Survey of Children’s Health to explore associations between ADHD, weeknight sleep insufficiency, and bedtime irregularity. 

"Sleep sufficiency" refers to the recommended amount of sleep for an individual. Sleep recommendations vary by age and other factors, such as health and lifestyle. For example, 7-9 hours is typically considered sufficient sleep for most adults, but an active teen may require closer to 10 hours of sleep per day.

Previous studies have shown that issues with both falling and staying asleep are common in individuals with ADHD.

The Study:

The team matched 7,671 children and adolescents with ADHD aged 3-17 to 51,572 controls.  

Noting that “The few available population-based studies examining sleep in children with ADHD have focused on circumscribed age ranges, limiting generalizability across childhood, and have seldom included controls,” and “bedtime irregularity has received limited empirical attention in children with ADHD,” this study focused on these aspects of sleep impairment. 

The study group excluded children and adolescents with ADHD with Down syndrome, current or lifetime cerebral palsy, and current or lifetime intellectual disability. In the control group, it excluded individuals with Down syndrome, cerebral palsy, intellectual disability, speech and language disorder, autism spectrum disorder, ADHD, anxiety, depression, behavioral or conduct problems, Tourette syndrome, and use of mental health services in the preceding 12 months. These groups were excluded to limit potential confounding factors.

After adjustment for covariates, parents of children and adolescents with ADHD reported weekday sleep insufficiency 65% more frequently than parents of controls.  

However, when comparing matched controls with children and adolescents with ADHD who were being treated with ADHD medication, there was no significant difference. 

Similarly, there was a small but significant effect size increase in bedtime irregularity among children and adolescents with ADHD relative to their matched controls. 

Yet there was also a small but significant effect size decrease in bedtime irregularity among those taking medication for ADHD relative to those who were unmedicated. 

The team noted, “Interestingly, here, ADHD medication use was linked to less bedtime irregularity across full and age-stratified samples, and not related to sleep insufficiency. However, research indicates the association between stimulant use and sleep problems is attenuated with longer duration of use, and also suggests the potential for stimulants to produce positive effects on sleep through reduced bedtime resistance. Further, ADHD medication type, not specified, may have influenced outcomes.” 

The Take-Away:

The study concluded that ADHD in children was linked to insufficient sleep and irregular bedtimes in a nationally representative sample, reinforcing and expanding previous research. The findings emphasize the influence of various factors on sleep insufficiency and bedtime irregularity, including race, screen time, poverty, ADHD severity, and depression.

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Background:

Noting that “the association between adult ADHD and dementia risk remains a topic of interest because of inconsistent results,” an Israeli study team tracked 109,218 members of a nonprofit Israeli health maintenance organization born between 1933 and 1952 who entered the cohort on January 1, 2003, without an ADHD or dementia diagnosis and were followed up to February 28, 2020. 

Israeli law forbids nonprofit HMOs from turning anyone away based on demographic factors,  health conditions, or medication needs, thereby limiting sample selection bias.  

The estimated prevalence of dementia in this HMO, as diagnosed by geriatricians, neurologists, or psychiatrists, is 6.6%. This closely matches estimates in Western Europe (6.9%) and the United States (6.5%). 

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Method:

The team considered, and adjusted for, numerous covariates: age, sex, socioeconomic status, smoking, depression, obesity, chronic obstructive pulmonary disease, hypertension, atrial fibrillation, heart failure, ischemic heart disease, cerebrovascular disease, diabetes, Parkinson’s disease, traumatic brain injury, migraine, mild cognitive impairment, psychostimulants. 

With these adjustments, individuals diagnosed with ADHD were almost three times as likely to be subsequently diagnosed with dementia as those without ADHD. Men with ADHD were two and a half times more likely to be diagnosed with dementia, whereas women with ADHD were over three times more likely, than non-ADHD peers. 

More concerning still, persons with ADHD were 5.5 times more likely to be subsequently diagnosed with early onset dementia, as opposed to 2.4 times more likely to be diagnosed with late onset dementia. 

On the other hand, the team found no significant difference in rates of dementia between individuals with ADHD who were being treated with stimulant medications and individuals without ADHD. Those with untreated ADHD had three times the rate of dementia. The team nevertheless cautioned, “Due to the underdiagnosis of dementia as well as bidirectional misdiagnosis, this association requires further study before causal inference is plausible.” 

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Conclusions and Relevance:

This study reinforces existing evidence that adult ADHD is associated with an increased risk of dementia. Notably, the increased risk was not observed in individuals receiving psychostimulant medication, however the mechanism behind this association is not clear.

These findings underscore the importance of reliable ADHD assessment and management in adulthood. They also highlight the need for further study into the link between stimulant medications and the decreased risk of dementia.

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Given the persistence of ADHD and its adverse effects on children and adolescents, one might expect caregivers to face greater parenting challenges, with potential effects on their own mental health. 

To what extent do parenting stress, depression, and – at the extreme – even suicidal ideation manifest themselves among caregivers of ADHD patients as opposed to caregivers of children and adolescents without ADHD? 

A pair of Korean researchers made use of their country’s single-payer health insurance system, which maintains records on virtually the entire population, to perform a nationwide population study. They used data from the Korean National Health and Nutrition Examination Surveys (KNHANES) covering the decade from 2011 to 2020. KNHANES is an annual survey using a sophisticated sampling design conducted by the Korean Ministry of Health and Welfare to represent the entire population of South Korea. 

The analysis included 14,428 individuals who had children younger than 19 at the time of participation. All were asked whether their child had ever been diagnosed with ADHD by a physician. The mental health problems of the parents were assessed in terms of perceived stress, depressive symptoms, and suicidality. 

Of the 14,428 participants, 8,298 (57.5 %) were mothers and 6,130 (42.5 %) were fathers. Of the mothers, 116 (1.4 %) had a child with ADHD, and of the fathers, 86 (1.4 %) had a child with ADHD. 

The researchers adjusted for the following confounders: age of caregiver, education level, household income, area of residence, employment status, alcohol consumption, smoking status, cohabitation status, number of children, and child’s age. 

After adjustment, mothers of ADHD patients fared significantly worse than mothers of typically developing children on all three categories of mental health problems. They were 67% more likely to report higher stress, three times as likely to report symptoms of depression, and 2.5 times more likely to report suicidal ideation.  

Yet that pattern did not carry over to fathers, where there was no significant difference in mental health indicators between fathers of children with ADHD and fathers of children without ADHD. 

The authors concluded, “Parents of children with ADHD, especially mothers, need community support and public health attention to help alleviate their mental health problems.” 

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Background: 

ADHD is commonly accompanied by psychiatric comorbidities that complicate its diagnosis and treatment. Roughly two out of three affected children and adolescents have one or more comorbid psychiatric disorder. 

Because the peak age of ADHD onset is typically a decade or more earlier than those for schizophrenia, depressive disorder, or bipolar disorder, it is essential to explore these comorbidities over an extended period. Populations studies help researchers identify broader patterns and trends within an entire population and includes adults as well as children. This type of study provides unique insights into the population at large, rather than a sample group.

In earlier studies the maximum follow-up period was twelve years, insufficient in view of the roughly ten years between onset of ADHD and onset of major psychiatric disorders. Also, previous nationwide population studies have included less than 150,000 participants. 

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The Study:

This study, relying on data from South Korea’s universal single-payer health insurance system, included over one and a half million individuals. Persons previously diagnosed with depression, bipolar disorder, tic disorder, or schizophrenia were excluded. 

382,434 individuals had been diagnosed with ADHD, while 1,169,279 were without an ADHD diagnosis.  

Propensity score matching ensured that potential confounders, both sociodemographic and clinical, were equalized for the ADHD and control groups. After matching, there were 353,898 individuals in each group. 

After these adjustments, individuals in the ADHD group were at least an order of magnitude more likely to subsequently be diagnosed with  psychiatric disorders than their peers without an ADHD diagnosis: 

• Almost eleven times more likely to be diagnosed with depressive disorder. 

• More than twelve times as likely to be diagnosed with bipolar disorder. 

• Over thirteen times more likely to be diagnosed with schizophrenia. 

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Conclusion:

The Korean study team concluded, “Overall, our findings suggest that upon prolonged examination, the risk of subsequent diagnoses of other psychiatric disorders in individuals with ADHD appears to be higher than that reported previously. … Therefore, patients with ADHD should be carefully screened for the presence of other psychiatric symptoms on a regular basis from an earlier age … It is advisable to have a follow-up period extending beyond 10 years to sufficiently identify the occurrence of comorbid disorders in patients with ADHD.” 

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Children with ADHD often face challenges in social interactions, leading to long-term consequences if not properly addressed. While various interventions exist, many fail to consider the broader social context in which these children interact. A recent study conducted in Bergen, Norway, explored how primary school teachers perceive their role in supporting children with ADHD who struggle socially and the strategies they use to assist them.

Investigating Teacher Perspectives

Researchers conducted semi-structured interviews with five focus groups of primary school teachers. Using reflexive thematic analysis, they identified two major themes:

1. Understanding Individual Needs in Context – Teachers emphasized that every child is unique, and ADHD should not define a student's social struggles. They highlighted the importance of considering the child’s specific social challenges within their broader environment.
2. Adapting Strategies Through Continuous Assessment – Teachers described their work as a dynamic and flexible process, adjusting their approaches based on the child's evolving needs. This included providing subtle background support as well as direct guidance in social interactions.

A Personalized Approach to Social Support

Rather than relying on standardized interventions, teachers tailored their strategies to foster an inclusive and supportive social environment. Their methods included both active participation in social situations and behind-the-scenes efforts to encourage peer inclusion and understanding.

Rethinking ADHD and Social Development

This study underscores the need to move beyond labels and recognize children with ADHD as individuals with distinct social needs. Teachers play a crucial role in shaping these children’s experiences, using flexible and personalized approaches to promote positive social interactions. By integrating social context and individualized support, educators can help children with ADHD build meaningful connections and navigate their social world more effectively.

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