What would you like to find today?

Methylphenidate(MPH) is one of the most widely-prescribed medications for children. Given that ADHD frequently persists over a large part of an individual’s lifespan, any side effects of medication initiated during childhood may well be compounded over time. With funding from the European Union, a recently released review of the evidence looked for possible adverse neurological and psychiatric outcomes.

From the outset, the international team recognized a challenge: “ADHD severity may be an important potential confounder, as it may be associated with both the need for long-term MPH therapy and high levels of underlying neuropsychiatric comorbidity.” Their search found a higy heterogeneous evidence base, which made meta-analysis inadvisable. For example, only 25 of 39 groups studies reported the presence or absence of comorbid psychiatric conditions, and even among those, only one excluded participants with comorbidities. Moreover, in only 24 of 67 studies was the type of MPH used (immediate or extended-release)specified. The team, therefore, focused on laying out an “evidence map” to help determine priorities for further research.

The team found the following breakdown for specific types of adverse events:

·      Low mood/depression. All three non-comparative studies found MPH safe. Two large cohort studies, one with over 2,300 participants, and the other with 142,000, favored MPH over the non-stimulant atomoxetine . But many other studies, including a randomized controlled trial(RCT), had unclear results. Conclusion: “the evidence base regarding mood outcomes from long-term MPH treatment is relatively strong, includes two well-powered comparative studies, and tends to favor MPH.”

·      Anxiety. Here again, all three non-comparative studies found MPH safe. But only two of seven comparative studies favored MPH, with the other five having unclear results. Conclusion: “while the evidence about anxiety as an outcome of long-term MPH treatment tends to favor MPH, the evidence base is relatively weak.”

·      Irritability/emotional reactivity. A large cohort study with over 2,300 participants favored MPH over atomoxetine . Conclusion: “the evidence base … is limited, although it includes one well-powered study that found in favor of MPH over atomoxetine.”

·      Suicidal behavior/ideation. There were no non-comparative studies, but all five comparative studies favored MPH. That included three large cohort studies, with a combined total of over a hundred thousand participants, that favored MPH over atomoxetine. Conclusion: “the evidence base … is relatively strong, and tends to favor MPH.”

·      Bipolar disorder. A very large cohort study, with well over a quarter-million participants, favored MPH over atomoxetine. A much smaller cohort study comparing MPH with atomoxetine , with less than a tenth the number of participants, pointed toward caution. Conclusion: “the evidence base … is limited and unclear, although it includes two well-powered studies.”

·      Psychosis/psychotic-like symptoms. By far the largest study, with over 145,000 participants, compared MPH with no treatment, and pointed toward caution. A cohort study with over 2,300participants favored MPH over atomoxetine. Conclusion: “These findings indicate that more research is needed into the relationship between ADHD and psychosis, and into whether MPH moderates that risk, as well as research into individual risk factors for MPH-related psychosis in young people with ADHD.”

·      Substance use disorders. A cohort study with over 20,000 participants favored MPH over anti-depressants, anti-psychotics, and no medication. Other studies looking at dosages and durations of treatment, age at treatment initiation, or comparing with no treatment or “alternative” treatment, all favored MPH except a single study with unclear results. Conclusion: “the evidence base … is relatively strong, includes one well-powered study that compared MPH with antipsychotic and antidepressant treatment, and tends to favor MPH.”

·      Tics and other dyskinesias. Of four noncomparative studies, three favored MPH, the other, with the smallest sample size, urged caution. In studies comparing with dexamphetamine, pemoline, Adderall, or no active treatment, three had unclear results and two pointed towards caution. Conclusion: “more research is needed regarding the safety and management of long-term MPH in those with comorbid tics or a tic disorder.”

·      Seizures or EEG abnormalities. With one exception, the studies had small sample sizes. The largest, with over 2,300 participants, compared MPH with atomoxetine, with inconclusive results. Two small studies found MPH safe, one had unclear results, and two others pointed towards caution. Conclusion: “While the evidence is limited and unclear, the studies do not indicate evidence for seizures as an AE of MPH treatment in children with no prior history … more research is needed into the safety of long-term MPH in children and young people at risk of seizures.”

·      Sleep Disorders. All three noncomparative studies found MPH safe, but the largest cohort study, with over 2,300 participants, clearly favored atomoxetine. Conclusion: “more research is needed into the relationship between ADHD, sleep, and long-term MPH treatment.”

·      Other notable psychiatric outcomes. Two noncomparative studies, with 118 and 289 participants, found MPH safe. A cohort study with over 700 participants compared with atomoxetine, with inconclusive results. Conclusion: “there is limited evidence regarding long-term MPH treatment and other neuropsychiatric outcomes, and that further research may be needed into the relationship between long-term MPH treatment and aggression/hostility.”

Although this landmark review points to several gaps in the evidence base, it mainly supports prior conclusions of the US Food and Drug Administration (FDA) and other regulatory agencies (based on short-term randomized controlled trials) that MPH is safe for the treatment of ADHD in children and adults. Given that MPH has been used for ADHD for over fifty years and that the FDA monitors the emergence of rare adverse events, patients, parents and prescribers can feel confident that the medication is safe when used as prescribed.

A Canadian team has published a systematic review examining the effectiveness of Mindfulness-Based Interventions (MBIs)for treating adults with ADHD. MBIs usually involves three forms of meditation –body scan, sitting meditation, and mindful yoga – that are intended to cultivate non-judgmental awareness of the present-moment experience. The team reviewed thirteen studies.

Three were single-group studies with no control group. One used dialectical behavior therapy (DBT). It reported mild to moderate improvements in ADHD symptoms, and substantial improvements in neurocognitive function (with standardized mean difference effect sizes from.99 to 2.22). A second enrolled both adults and adolescents in a mindful awareness program (MAP) which included a psychoeducational component. It found improvements in self-reported ADHD symptoms, with standardized mean difference(SMD) effect sizes running from .50 to.93. Following training, it also reported improvement in attentional conflict (.93) set-shifting (.43). The third study also used DBT, focused on acceptance, mindfulness, functional behavioral analysis, and psychoeducation. ADHD symptoms showed mild improvement (.22), and functional impairment was slightly reduced (.15) and remained stable at a 3-month follow-up.

The other ten studies used control groups. One used MAP and carefully stratified participants based on their ADHD medication status, then randomly assigned them to mindfulness treatment or waitlist. It reported large effect sizes in the improvement of self-reported and clinician ratings of ADHD symptoms (1.35 to 3.14), executive functioning (1.45 to 2.67), and self-reported emotion regulation (1.27 to 1.63). In another study, non randomly assigned adults to either mindfulness-based training (MBT) or skills training. Effect sizes were small to medium (.06 to .49), with 31% of MBT participants showing some improvement, versus only 11% of skills training participants.

Another study involved a controlled trial of college students with ADHD, randomized to receive either MBT or skills treatments. Treatment response rates were higher for MBT (59-65%, vs. 19-25%). At follow-up, the effect size for MBT on ADHD symptoms was large (.84), and similarly large on executive functioning (.81).

Another study tried a year’s worth of mindfulness training on poor responders to medication. Participants who received the treatment were compared to others who were waitlisted. The study reported a medium effect size (.63) in reducing the severity of ADHD.

Another looked at the impact of MAP on affective problems and impaired attention. It compared adults with ADHD and healthy controls who participated in MAP sessions with similar patients and controls who did not. The authors reported that MAP improved sustained attention and mood, with medium to large effect sizes (.50 to .80).

A recent study explored the impact of MAP on neurocognitive performance with a randomized controlled trial. Following an8-week mindfulness training, researchers “found a significant decrease in ADHD symptoms and significant improvement in task performance in both the MAP and the psychoeducation comparison group post - versus pre-intervention but did not find evidence for a significant main effect of treatment or a significant interaction effect on any ADHD symptoms (self-and observer-rated) nor on task performance (WM).”

Another study randomly assigned adults with ADHD either to a waitlist or to mindfulness-based cognitive therapy (MBCT). It found that MBCT led to a medium-to-large reduction in self-reported ADHD symptoms (.64) and a large reduction in investigator-reported symptoms (.78). It also found large (.93) improvements in executive functioning.

An 11th study looked at the effects of MBCT on neuropsychological correlates (event-related potentials(ERPs)) of performance monitoring in adults with ADHD. Half the patients were randomly assigned to MBCT, the other half to waitlist. MBCT produced reduced inattention, hyperactivity/impulsivity, and global ADHD index symptoms with medium to large effect sizes (.49 to .93).

A 12th study randomly assigned college students to MBCT or waitlist. At follow-up, participants who had received MBCT exhibited large (1.26) reductions in ADHD symptoms as well as greater treatment response rates (57%-71% vs. 23%-31%) versus waitlist. They also registered greater improvement on most neuropsychological performance and attentional scores.

Finally, another study compared the efficacy of MBCT plus treatment as usual (TAU) versus TAU only in reducing core symptoms in adults with ADHD. Participants were randomly assigned to an 8-weekly group therapy including meditation exercises, psycho education, and group discussions, or to TAU only, including pharmacotherapy and/or psycho education. At 6-month follow-up, MBCT+TAU patients reported large (SMD = .79) improvements in ADHD symptoms relative to TAU patients.

Overall, these are promising results for mindfulness-based interventions, and all the more so for those who do not respond well to drug therapy. Nevertheless, they must be seen as tentative. The sum total of participants over all thirten studies was just 753, or an average of only 58 per study. There was too much variation in the studies to perform a meta-analysis. Only one of the studies included a healthy (non-ADHD) control group. And only one study received a perfect sce by Cochrane Collaboration standards.  Most studies did not use a suitable control group, i.e., on in which there was an expectation of benefit from participating.  As the authors noted, “Attrition bias was found to have high or unclear risk in more than a half of the studies. The reason for dropout of participants was not always clearly specified in those studies, so it is difficult to decide if it might be related to adverse effects or to some discomfort with treatment or instead to some incidental reasons.”

Mindfulness has been defined as “intentionally directing attention to present moment experiences with an attitude of curiosity and acceptance.” Mindfulness-based interventions (MBIs) aim to improve mindfulness skills.

A newly-published meta-analysis of randomized controlled trials (RCTs) by a team of British neurologists and psychiatrists explores the effectiveness of MBIs in treating a variety of mental health conditions in children and adolescents. Among those conditions is the attention deficit component of ADHD.

A comprehensive literature search identified studies that met the following criteria:

1)    The effects of mindfulness were compared against a control condition – either no contact, waitlist, active, or attention placebo. The waitlist means the control group receives the same treatment after the study concludes. Active control means that a known, effective treatment (as opposed to a placebo) is compared to an experimental treatment. Attention placebo means that controls receive a treatment that mimics the time and attention received by the treatment group but is believed not to have a specific effect on the subjects. Participants were randomly assigned to the control condition.

2)    The MBI was delivered in more than one session by a trained mindfulness teacher, involved sustained meditation practice, and it was not mixed in with another activity such as yoga.

Eight studies evaluating attention deficit symptoms, with a combined total of 1,158 participants, met inclusion criteria. The standardized mean difference (SMD) was 0.19, with a 95% confidence range of 0.04 to 0.34 (p = .02). That indicates a small effect size for MBIs in reducing attention deficit symptoms. Heterogeneity was low (I2 = 35, p =.15), and the Egger test showed little sign of publication bias (p = 0.42).

When looking only at studies with active controls, five studies with a total of 787 participants yielded an SMD of 0.13, with a 95% confidence interval of -0.01 to 0.28 (p = .06), indicating a tiny effect size that failed to reach significance. Active controls most commonly received health education, with a few receiving social responsibility training or  Hatha yoga.

Overall, this meta-analysis suggests limited effectiveness, especially when compared with active controls.  If MBIs are effective for ADHD, their effect on symptoms is very small.  Thus, such treatments should not be used in place of the many well-validated, evidenced-based therapies available. Whether longer periods of MBI (training times varied between 2 and 18 hours spread out over 2 to 24 weeks) might result in greater effect sizes remains unexplored

Behavioral disinhibition is a trait associated with both ADHD and several genes that affect dopamine signaling. Anew study by three American medical researchers set out to examine how threaded risk genes – DRD4 (dopamine 4 receptor density), DAT1 (dopamine 1transporter), and DBH (dopamine beta-hydroxylase) – affect estimated life expectancy in young adulthood.

The method used was a longitudinal study of 131 hyperactive children and 71 matched controls through early adulthood. The original evaluations were done in 1979-1980, when both groups were children in the 4 to 12 age range. They were reevaluated in1987-1988 as adolescents aged 12 to 20. The next follow-up was in 1992-1996 in early adulthood, aged 19 to 25. The final follow-up was in 1998-2004, as adults aged 24 to 32. All agreed to physical examinations that formed the basis for calculating estimated life expectancy using actuarial tables that factor in the effects of smoking, body mass index, alcohol, and other risk factors on expected longevity. Participants also provided blood samples that enabled gene typing.

For the DAT1gene, participants who had the homozygous nine-repeat allele (9/9) had an a five-year reduction in estimated life expectancy relative to those with the ten-repeat allele (10/10). Those with the intermediate (9/10) configuration had a three-year reduction in estimated life expectancy.

For the DBHTaq1 gene, those with a heterozygous (A1/A2) combination had almost a three-year reduction in estimated life expectancy relative to those with homozygous (A1/A1 or A2/A2) configurations.

For DRD4, on the other hand, no significant differences were found for estimated life expectancy.

In a related study, several background traits were found to be significantly predictive of variance in estimated life expectancy. The largest of these was behavioral disinhibition, followed by verbal IQ, self-rated hostility, and a nonverbal fluency test. But no significant differences were found between any of the gene polymorphisms on any of these four measures, indicating that the present gene associations were independent of the background traits.

The researchers next sought to determine which variables used in the estimated life expectancy calculations were associated with the two significant genes. For DBH, one variable stood out. Those with the A1/A2 heterozygous pairings had almost twice the alcohol consumption of those with homozygous pairings (p = 0.023).

For DAT1, two variables stood out. Overall, the 9/9 pairings smoked two and a half times as much as the 10/10 pairings, with the 9/10 pairings midway between the extremes(p = 0.036). They were also 73 percent more likely to be smokers relative to the 10/10 pairings, and 61 percent more likely relative to the 9/10 pairings. They also had significantly less education than the 10/10 pairings, with the 9/10pairings again being intermediate (p = 0.027).

An obvious limitation of the study was its small sample size. The authors cautioned, “our findings should be considered quite preliminary and in need of much greater research before being given much weight in the literature or in public policy.”

“With these limitations in mind,” they concluded, “the present study demonstrated that two ADHD risk genes (DBH and DAT1) independently contributed to a reduction in ELE [estimated life expectancy] beyond the second order variables of behavioral disinhibition, IQ, hostility, and nonverbal fluency that contributed in the related study to variation in ELE. The gene polymorphisms seemed to be influencing ELE through their affiliation with first-order or more proximal factors related to ELE such as education, smoking, alcohol use, and possibly exercise.”

A Dutch and German team compared the performance of 45 adults with ADHD and 51 normally developing controls on a battery of standardized tests and questionnaires designed to assess competence in financial decision-making (FDM). These were supplemented with neuropsychological tests, as well as evaluations of each participant’s personal financial situation.

The two groups had roughly comparable demographic characteristics. There were no significant differences in age, gender balance, years of education, or work status. Students were excluded from both groups because they tend to be financially dependent and to have little or no income.

The ADHD group scored more than three times higher on self-report questionnaires for both the retrospective assessment of childhood symptoms ( Wender Utah Rating Scale—Childhood) and for evaluating current symptoms of ADHD (ADHD self-report scale). Researchers did not perform clinical evaluations of ADHD.

To determine their personal financial situation, participants were asked about their income range as well as, “Do you have debts other than mortgage or study loans?”;“Do you receive social security?”; “Do you have a savings account?”;“Do you save actively, that is, do you put money on your savings account on a regular basis?”; “Do you save for retirement?”; and “Do you own a house?” They were also asked how much they set aside in monthly savings, and, where applicable, how much they receive in social security.

On five out of nine criteria, significant differences emerged between the two groups. Whereas healthy controls had median incomes in the range of €35,000 to €45,000, for those with ADHD it was dramatically lower, between €15,000 and €25,000. Healthy controls also had twice as much disposable income. Whereas almost half of adults with ADHD reported debts other than mortgage or educational loans, only a third as many healthy adults had such debt. And whereas only slightly over half of those with ADHD reported having savings accounts, among healthy adults it was more than six out of seven. Finally, healthy controls were four times as likely to own a home.

Participants were then given standardized tests to evaluate financial competence, financial decision-making capacity, financial decision styles, the ability to make financial decisions using decision rules, the capacity to make decisions with implications for the future, impulsive buying tendencies, and a gambling task as a measure of emotional decision-making.

Adults with ADHD scored significantly lower than healthy adults on the financial competence test, and in particular, on financial abilities, financial judgment, financial management, and financial support resources. Similar outcomes emerged from the financial decision-making capacity test, especially when it came to identifying and understanding relevant information. Adults with ADHD were also significantly more likely to use avoidant and spontaneous decision styles. They also showed significantly more temporal discounting, meaning they tended to prefer immediate gratification over long-term financial security. That translated into significantly higher propensities to buy on impulse. In all cases these differences had large effect sizes.

Finally, participants were tested on nine cognitive functions: information processing speed, vigilance and selective attention, inhibition, interference, figural fluency, cognitive flexibility, task switching, verbal working memory, and numeracy.

Those with ADHD performed significantly worse, with medium effect sizes, on three cognitive measures: vigilance, interference, and numeracy. There were no significant differences on the other six measures.

The authors concluded, “The results show that the personal financial situation of adults with ADHD was less optimal than the financial situation of healthy controls. Furthermore, adults with ADHD showed significantly decreased performances compared with healthy controls in five out of seven tasks measuring FDM and on measures of vigilance, interference, and numeracy. However, mediation analyses indicated that differences in cognitive functioning cannot fully explain the differences with regard to FDM between adults with ADHD and healthy controls.”

They also pointed to limitations of the study. One is that 19 of the 45 adults with ADHD had comorbid disorders, of which three were substance dependencies. However, removing them had little effect on the outcome. Another limitation was that adults with ADHD were off medication during the testing, so it is unclear how stimulants would affect the test outcomes. The authors state, “The influence of treatment use should, therefore, be explored in future research on FDM and adults with ADHD.”

ADHD , especially when untreated impairs patients and creates difficulties in families. Although these are the proximal targets of treatment, ADHD also burdens society due, for example, to underemployment and use of health resources.   A recent study assessed economic burden using the Danish population registries, researchers, which link medical information with employment, education, crime, and social care registers while maintaining confidentiality. They identified 5,269 adults with adult ADHD who had not been diagnosed with ADHD in childhood and, we can assume, were probably not treated for the disorder. They excluded patients with other psychiatric diagnoses, and cases without a same sex sibling free of any diagnosed psychiatric diagnoses. That left 460 pairs of same-sex siblings, one with adult ADHD and the other with no psychiatric diagnosis. They selected the non-ADHD sibling closest in age to the ADHD sibling. Using siblings mitigated effects of genetics and upbringing between the ADHD group and normally developing controls.

Looking at personal income (combining work income and public transfers), adults with ADHD on average brought home about 12,000 Euros less – almost a third less – than their sibling counterparts. They also paid 40% less tax. Balancing that out, their after-tax income was roughly 7,500 Euros less than their siblings. With the additional personal cost of prescribed medication (prescriptions are relatively inexpensive in Denmark, and copayments even more so) the net personal cost to adults with ADHD was 7,700 Euros.

The net public costs were considerably greater. That was primarily due to the reduction in taxes paid (about 4,500 Euros) and increase in income replacement transfers (just over 5,500 Euros).The cost of additional crimes committed by adults with ADHD added another 1,000 Euros. Additional primary and secondary health care costs contributed another 1,000 Euros. Subsidies for prescribed medicines added 661 Euros, but that was partly counterbalanced by a reduction of 344 Euros in education costs. There were no significant differences in costs from traffic accidents or adult continuation of foster care. Overall, the net per capita public cost of adults with ADHD was just over 12,400 Euros each year.

Combining public and private costs, the per capita economic burden of adult ADHD was just over 20,000 Euros each year.

The study could not evaluate the extent to which ADHD treatment may reduce economic burden but given many studies that show treatment for ADHD reduces impairments, we would expect treatment to have a positive impact on economic burden. These results are extremely important for policy makers and for those who control the allocation of treatment in health care systems.  Although treating ADHD incurs costs, not treating in incurs even greater costs in the long run

Drivers with ADHD are far more likely to be involved in crashes, to be at fault in crashes,to be in severe crashes, and to be killed in crashes. The more severe the ADHD symptoms, the higher the risk. Moreover, ADHD is often accompanied by comorbid conditions such as oppositional-defiant disorder, depression, and anxiety that further increase the risk.

What can be done to reduce this risk? A group of experts has offered the following consensus recommendations:

·   Use stimulant medications. While there is no reliable evidence on whether non-stimulant medications are of any benefit for driving, there is solid evidence that stimulant medications are effective in reducing risk. But there is also a “rebound effect” in many individuals after the medication wears off, in which performance actually becomes worse than if had been prior to medication. It is therefore important to time the taking of medication so that its period of effectiveness corresponds with driving times. If one has to drive right after waking up, it makes sense to take a rapid acting form. The same holds for late night driving that may require a quick boost.

·   Use a stick shift vehicle wherever possible. Stick shifts make drivers pay closer attention than automatic transmissions. The benefits in alertness are most notable in city traffic. But using a stick shift is far less beneficial in highway driving, where shifting is less frequent.

·  Avoid cruise control. Highways can be monotonous, making drivers more prone to boredom and distraction. That is even more true for those with ADHD, so it is best to keep cruise control turned off.

·   Avoid alcohol. Drinking and driving is a bad idea for everyone, but, once again, it’s even worse for those with ADHD. Parents should consider a no-questions-asked policy of either picking up their teenager anytime and anywhere, or setting up an account with a ride-sharing service.

·   Place the smartphone out of reach and hearing. Cell phone use is as about as likely to impair as alcohol.Hands-free devices only reduce this risk moderately, because they continue to distract. Texting can be deadly. Sending a short text or emoticon can be the equivalent of driving 100 yards with one’s eyes closed. Either turn on DoNot Disturb mode, or, for even greater effectiveness, place the smart phone in the trunk.

·   Make use of automotive performance monitors. These can keep track of maximum speeds and sudden acceleration and braking, to verify that a teenager is not engaging in risky behaviors.

·   Take advantage of “graduated driver’s licensing laws” wherever available. These laws forbid the presence of peers in the vehicle for the first several (for example, six) months of driving.Parents can extend that period for teenagers with ADHD, or set it as a condition in states that lack such laws.

·  Encourage practicing after obtaining a learner’s permit. Teenagers with ADHD generally require more practice than those without. A “pre-drive checklist” can be a good place to start. For example:check the gas, check the mirrors, make sure the view through the windows is unobstructed, put cell phone in Do Not Disturb mode and place it out of reach,put on seat belt, scan for obstacles.

·   Consider outsourcing. Look for a driving school with a professional to teach good driving skills and habits.

Experts do not agree on whether to delay licensing for those with ADHD. On the one hand,teenagers with ADHD are 3-4 years behind in the development of brain areas responsible for executive functions that help control impulses and better guide behavior. Delaying licensing can reduce risk by about 20 percent. On the other hand, teens with ADHD are more likely to drive without a license, and no one wants to encourage that, however inadvertently. Moreover, graduated driver’s licensing laws only have legal effect on teens who get their licenses at the customary age.

‍

Many college students truly have ADHD and deserve to be treated but some attempt to fake ADHD symptoms with the goal of getting stimulant medications for non-medical uses such as studying and getting high.  Some students who fake ADHD also seek to gain accommodations that would give them additional time to complete exams. To address this issue, two psychologists examined data from 514 university students being assessed for ADHD to evaluate the ability of assessment tools to detect students who fake ADHD symptoms.

All participants had asked to be assessed to determine whether they could qualify for disability services. This was therefore by no means a random sample of university students, and could be expected to include some non-ADHD individuals seeking the benefits of an ADHD diagnosis.; however, this offered a good opportunity to explore which combination of tools would yield the best accuracy, and be best at excluding malingerers.

That was achieved by using both multiple informants and multiple assessment tools, and comparing results. Self-assessment was supplemented by assessment by other informants (e.g. parent, partner, friend, or other relative). These were supplemented with symptom validity tests to check for telltale highly inconsistent symptom reporting, or symptom exaggeration, which could signal false positives.

On the other hand, some individuals with ADHD have executive functioning problems that may make it difficult for them to reliably appraise their own symptoms on self-assessment tests, which can lead to false negatives. Performance validity tests were therefore also administered, in order to detect poor effort during evaluation, which could lead to false negatives.

Observer reporting was found to be more reliable than self-reporting, with significantly lower inconsistency scores (p< .001), and significantly higher exaggeration scores (p < .001). More than twice as many self-reports showed evidence of symptom exaggeration as did observer reports. This probably understates the problem when one considers that the observer reports were performed not by clinicians but by parents and partners who may themselves have had reasons to game the tests in favor of an ADHD diagnosis.

Even so, the authors noted, “External incentives such as procurement of a desired controlled substance or eligibility for a desired disability accommodation are likely to be of more perceived value to those who directly obtain them.” They suggested compensating for this by making ADHD diagnoses only on the basis of positive observer tests in addition to self-reports: “Applying an ‘and’ rule—one where both self- and observer reports were required to meet the diagnostic threshold— generally cut the proportions meeting various thresholds at least in half and washed out the differences between the adequate and inadequate symptom validity groups.”

They also recommended including formal tests of response validity, using both symptom validity tests and performance validity tests. Overall, they found that just over half the subsample of 410 students administered performance validity tests demonstrated either inadequate symptom or performance validity.

Finally, they recommended “that clinicians give considerable weight to direct, objective evidence of functional impairment when making decisions about the presence of ADHD in adults. The degree to which symptoms cause significant difficulty functioning in day-to-day life is a core element of the ADHD diagnostic criteria (American Psychiatric Association,2013), and it cannot be assumed that significant symptoms cause such difficulty, as symptoms are only moderately associated with functional impairment. … we urge clinicians to procure objective records (e.g., grade transcripts, work performance evaluations, disciplinary and legal records) to aid in determining functional impairment in adults assessed for ADHD.”