March 27, 2022
Israel has a military draft that applies to males and females alike, except orthodox women and orthodox male seminary(yeshiva) students, who are exempt. Upon turning 17 every Israeli undergoes a medical review, including both a physical and psychiatric assessment, in preparation for the draft. The Draft Board Registry maintains comprehensive health information on all unselected Israelis until they turn 21. The registry also tracks all family members of draft registrants, including full siblings.
An Israeli study team used registry records from 1998 through2014 to obtain data for a total of over a million individuals (1,085,388). Because of the exemption for orthodox women, 59% were male.
The team identified 903,690 full siblings in the study population (58% males), including 166,359 male-male sibling pairs, 104,494 female-female sibling pairs, and 197,571 opposite-sex sibling pairs.
Next, the team identified all cases in the study population with a diagnosis of a psychiatric disorder, low IQ (≥2 standard deviations below the population mean), Type-1 diabetes, hernia, or hematological malignancies. It matched each case with ten age- and sex-matched controls selected at random from the study population. Then, for each case and case-matched controls, it identified all siblings.
There were 3,272 cases receiving treatment for ADHD, 2,128 with autistic spectrum disorder, 9,572 with severe/profound intellectual disability, 7,902 with psychotic disorders, 9,704 with mood disorders, 10,606with anxiety disorders, 24,815 with personality disorders, 791 with substance abuse disorders, 31,186 with low IQ, 2,770 with Type-1 diabetes, 30,199 with a hernia, and 931 with hematological malignancies.
Draftees with ADHD were five and a half times more likely to have a sibling with ADHD than controls.
There were no significant associations between ADHD and any of the somatic disorders - Type-1 diabetes, hernia, or hematological malignancies - nor between ADHD and low IQ.
There were also no significant associations between ADHD and autism spectrum disorder, severe/profound intellectual disability, mood disorders, and substance use disorders.
On the other hand, draftees with ADHD were more than 40% more likely to have siblings with anxiety or personality disorders than controls.
Surprisingly, draftees with ADHD were less than half as likely to have siblings with psychotic disorders than controls.
There were some limitations. The psychiatric classification system used by the Israeli military did not permit assessing the risk of bipolar disorder and depression separately. That meant having to use a broader category of mood disorders, including both disorders. In addition, the military diagnostic system does not allow diagnosis of comorbid psychiatric disorders in the same individual, instead of assigning only the most severe diagnosis.
Mark Weiser, Or Frenkel, Daphna Fenchel, DoritTzur, SvenSandin, Magdalena Janecka, Linda Levi, Michael Davidson, Lucian Laor, EyalFruchter, and Abraham Reichenberg: "Familial clustering of psychiatric disorders and low IQ, Psychological Medicine (2021), published online, https://doi.org/10.1017/S0033291721004852.
What are we to make of adults who exhibit the diagnostic criteria for ADHD, but are nevertheless high-functioning and successful? A trio of British investigators has just published six case studies that explore this question. It would have been better for them to have conducted a much larger, controlled research study but, in the absence of such data in the area, these case studies are intriguing and may help guide more informative research.
The authors recruited six successful men between the ages of 30 and 65 from a National Health Service tertiary service in London. Four were in long-term relationships, with children. All had good jobs.
In open-ended taped interviews of up to an hour in length, each was asked three questions:
1. What do you think are the advantages and disadvantages of having ADHD?
2. Please describe a time when you felt that your ADHD helped you to achieve something?
3. What aspects of your ADHD would you miss if it went away?
Hyper-focus in ADHD is generally considered a deficit, inset-shifting, and task-switching. But the authors report that participants associated it with productivity. One said, “I think the energy that the ADHD brain seems to have....it’s unfocused, quite scattered, chaotic and a bit random...but give that brain something that you can tune into, and it’s your interest, then all that random stuff just goes boom... I get this incredible intense concentration and that’s great for work.”
Participants also saw advantages in divergent thinking, with one stating, “I’m an artist.... a creative type... a Bohemian.... you are most likely to be a creative person if you are a divergent thinker....and not convergent... I am very creative and that’s through and through... I’m a fine art graduate, a musician, a published poet, an entrepreneur, a performer.”
All the participants reported being seen as nonconformists. Depending on a viewpoint, that can be seen as either detrimental or advantageous.
Impulsivity is a core symptom of ADHD. Participants however related it to bravery, and more specifically adventurousness, spontaneity, and thrill-seeking. One said, “thrill-seeking is an ADHD thing... I can list in my life have done white water rafting, bungee jumping, hand-glider pilot … I have done a lot in my life and achieved a lot and experienced a lot... Furthermore, I would see a lot of that as being quite positive, and a lot of that is ADHD drive.”
Another common theme was high energy and “spirit.” One participant said, “I’ve got all this energy.... a lot of energy... whatever it's to do with... nature/nurture/spiritual stuff.”
These testimonials are useful as a check on the usual narrative of impairment. ADHD does not predestine all it afflicts to an unfulfilling life. Many, often assisted by medication, still lead exciting, successful, rewarding lives. Yet, we must be cautious in concluding that these individuals were successful because of their ADHD. It is possible, even likely, that they had other strengths such as high intelligence that compensated for their ADHD symptoms. We can not know from this report if their lives had been even more fulfilling or successful in the absence of ADHD. See, for example, my blog about highly intelligent people with ADHD: https://www.linkedin.com/pulse/20141126141502-65669938-smart-people-can-have-adhd-too/.
While the authors concede that “generalizing the findings of this study is not easy to do,” they inexplicably “also argue that the positive aspects we found are relevant to other adults with ADHD regardless of sample size, age, gender or ethnicity.” It is not possible to draw such a definitive conclusion without a much larger sample.
On a hopeful note, they conclude, “This is a study that reaches out to people with lived experience of ADHD: service users, patients, family members, carers, partners, to say that not all symptoms of ADHD are maleficent. Recovery, high functionality, and flourishing with ADHD are possible. Too often people with lived experience hear about ADHD deficits, functional impairments, and associations with substance misuse, criminality, or other disadvantages on almost every level of life (school, work, relationships). … This study affirms the positive human qualities, assets, and attributes in ADHD that can promote and sustain high functioning and flourishing.” I fully endorse the idea that those with ADHD can have wonderful lives, especially if they receive appropriate treatment, both medical and psychological.
China is the outstanding economic growth story of the early twenty-first century. According to the World Bank, China has “experienced the fastest sustained expansion by a major economy in history – and has lifted more than 800 million people out of poverty.”
That expansion has been accompanied by major investments in medical research, and medical treatment capability, especially in the major urban centers that have spearheaded the boom. Life expectancy has risen from 71 in 2000 to 77 in 2019, nearing the U.S. level of 79.
Yet when it comes to pharmaceutical treatment of ADHD, China is an outlier, as revealed by a new study exploring the data in the two main medical insurance programs for its urban population.
The Urban Employee Basic Medical Insurance(UEBMI) covers both employers and employees in public and private workplaces, while the Urban Residents Basic Medical Insurance (BMI) covers the unemployed. As of 2014, these programs cover over 97% of urban residents. The China Health Insurance Research Association (CHIRA) database is a random sampling database from the UEBMI and UBMI databases.
The study population consisted of residents of the 63 cities in the CHIRA database from 2013 through 2017. Prescription prevalence was calculated by dividing the total number of patients prescribed ADHD medications in the CH IRA database by the urban population of the included cities, which was two hundred million as of 2017.
Other studies have found the prevalence of ADHD among Chinese children and adolescents to be about 6.5%, comparable to North American and European countries. Yet, the prescription prevalence of ADHD medications was 0.036% among those aged 0–14 years in 2017 in China. In other words, only about one in every two hundred youths with ADHD were being prescribed pharmaceutical treatments.
For further context, among other economically prosperous countries in Asia, Australia, North America, and Europe, the lowest prescription prevalence of ADHD medications is 0.27% in France, which is still over seven times higher than the Chinese level.
Among Chinese urban dwellers from 15 through 64 years of age, ADHD prescription prevalence in 2017 dropped by a further order of magnitude (over tenfold) to 0.003%, and among those 65 and older, to a scant 0.001%.
The Chinese study team suggested several likely contributing factors:
Sleep disorders are one of the most commonly self-reported comorbidities of adults with ADHD, affecting 50 to 70 percent of them. A team of British researchers set out to see whether this association could be further confirmed with objective sleep measures, using cognitive function tests and electroencephalography (EEG).
Measured as theta/beta ratio, EEG slowing is a widely used indicator in ADHD research. While it occurs normally in non-ADHD adults at the conclusion of a day, during the day it signals excessive sleepiness, whether from obstructive sleep apnea or neurodegenerative and neurodevelopmental disorders. Coffee reverses EEG slowing, as do ADHD stimulant medications.
Study participants were either on stable treatment with ADHD medication (stimulant or non-stimulant medication) or on no medication. Participants had to refrain from taking any stimulant medications for at least 48 hours prior to taking the tests. Persons with IQ below 80 or with recurrent depression or undergoing a depressive episode were excluded.
The team administered a cognitive function test, The Sustained Attention to Response Task (SART). Observers rated on-task sleepiness using videos from the cognitive testing sessions. They wired participants for EEG monitoring.
Observer-rated sleepiness was found to be moderately higher in the ADHD group than in controls. Although sleep quality was slightly lower in the sleepy group than in the ADHD group, and symptom severity slightly greater in the ADHD group than the sleepy group, neither difference was statistically significant, indicating extensive overlap.
Omission errors in the SART were strongly correlated with sleepiness level, and the strength of this correlation was independent of ADHD symptom severity. EEG slowing in all regions of the brain was more than 50 percent higher in the ADHD group than in the control group and was highest in the frontal cortex.
Treating the sleepy group as a third group, EEG slowing was highest for the ADHD group, followed closely by the sleepy group, and more distantly by the neurotypical group. The gaps between the ADHD and sleepy groups on the one hand, and the neurotypical group on the other, were both large and statistically significant, whereas the gap between the ADHD and sleepy groups was not. EEG slowing was both a significant predictor of ADHD and of ADHD symptom severity.
The authors concluded, “These findings indicate that the cognitive performance deficits routinely attributed to ADHD … are largely due to on-task sleepiness and not exclusively due to ADHD symptom severity. … we would like to propose a simple working hypothesis that daytime sleepiness plays a major role in cognitive functioning of adults with ADHD. … As adults with ADHD are more severely sleep deprived compared to neurotypical control subjects and are more vulnerable to sleep deprivation, in various neurocognitive tasks they should manifest larger sleepiness-related reductions in cognitive performance. … One clear testable prediction of the working hypothesis would be that carefully controlling for sleepiness, time of day, and/or individual circadian rhythms would result in a substantial reduction in the neurocognitive deficits in replications of classic ADHD studies.”
