Researchers Have Found the First Risk Genes for ADHD

Stephen V. Faraone, PhD on October 25, 2018

Our genes are very important for the development of mental disorders – including ADHD, where genetic factors capture up to 75% of the risk. Until now, the search for these genes had yet to deliver clear results. In the 1990s, many of us were searching for genes that increased the risk for ADHD because we know from twin studies that ADHD had a robust genetic component. Because I realized that solving this problem required many DNA samples from people with and without ADHD, I created the ADHD Molecular Genetics Network, funded by the US NIMH. We later joined forces with the Psychiatric Genomics Consortium (PTC) and the Danish iPSYCH group, which had access to many samples.

The result is a study of over 20,000 people with ADHD and 35,000 who do not suffer from it – finding twelve locations (loci) where people with a particular genetic variant have an increased risk of ADHD compared to those who do not have the variant. The results of the study have just been published in the scientific journal Nature Genetics, https://www.nature.com/articles/s41588-018-0269-7.

These genetic discoveries provide new insights into the biology behind developing ADHD. For example, some of the genes have significance for how brain cells communicate with each other, while others are important for cognitive functions such as language and learning.

We study used genomewide association study (GWAS) methodology because it allowed us to discover genetic loci anywhere on the genome. The method assays DNA variants throughout the genome and determines which variants are more common among ADHD vs. control participants. It also allowed for the discovery of loci having very small effects. That feature was essential because prior work suggested that, except for very rare cases, ADHD risk loci would individually have small effects.

The main findings are:

  1. A) we found 12 loci on the genome that we can be certain harbor DNA risk variants for ADHD. None of these loci were traditional ‘candidate genes’ for ADHD, i.e., genes involved in regulating neurotransmission systems that are affected by ADHD medications. Instead, these genes seem to be involved in the development of brain circuits.
  2. B) we found a significant polygenic etiology in our data, which means that there must be many loci (perhaps thousands) having variants that increase risk for ADHD. We will need to collect a much larger sample to find out which specific loci are involved;

We also compared the new results with those from a genetic study of continuous measures of ADHD symptoms in the general population. We found that the same genetic variants that give rise to an ADHD diagnosis also affect inattention and impulsivity in the general population. This supports prior clinical research suggesting that, like hypertension and hypercholesteremia, ADHD is a continuous trait in the population. These genetic data now show that the genetic susceptibility to ADHD is also a quantitative trait comprised of many, perhaps thousands, of DNA variants

The study also examined the genetic overlap with other disorders and traits in analyses that ask the questions: Do genetic risk variants for ADHD increase or decrease the likelihood a person will express other traits and disorders.  These analyses found a strong negative genetic correlation between ADHD and education. This tell us that many of the genetic variants which increase the risk for ADHD also make it more likely that persons will perform poorly in educational settings. The study also found a positive correlation between ADHD and obesity, increased BMI and type-2 diabetes, which is to say that variants that increase the risk of ADHD also increase the risk of overweight and type-2 diabetes in the population.

This work has laid the foundation for future work that will clarify how genetic risks combine with environmental risks to cause ADHD. When the pieces of that puzzle come together, researchers will be able to improve the diagnosis and treatment of ADHD.

Is There A Relationship Between ADHD And Migraines?

Stephen V. Faraone, PhD on October 18, 2018

A Danish team recruited 29,489 participants from among voluntary blood donors between the ages of 17 and 67, ensuring a large sample size. Participants were asked to complete two simple questionnaires on digital tablets. One asked two questions: “Have you ever had migraine?” and “Have you ever had visual disturbances lasting 5-60 min followed by headache?” A yes to either was considered positive for migraine. The other used the ADHD Self-Report Scale, with 18 ADHD symptoms evaluated on a five-point scale.

Excluding those who did not answer all questions left 26,456 participants. The risk for migraines among those with ADHD was nearly twice the risk for others. The odds ratio (OR) was 1.8, with a 95 percent confidence interval from 1.53 to 2.12 (p < 0.001). The OR was higher among females (2.01) than males (1.64). For those with visual disturbances, the OR was higher (1.98) than for those without (1.52). The association disappeared in those over 60, with an OR essentially equal to one (0.98, 95% CI = 0.84 – 1.15, p = 0.8).

Although the authors concluded, “We demonstrate a significant comorbidity between migraine and ADHD in adults, and this is most prominent for participants with migraine with visual disturbances,” the significance to which they refer are of the p-values, and should not be misinterpreted as an indication of a strong association, as the odds ratios point variably to weak, and weak-to-moderate associations, depending on subpopulations. The work is, however, important as it points to another somatic comorbidity of ADHD. That list is growing and now includes obesity, eczema and asthma.

REFERENCES

Thomas Folkmann Hansen, Louise K. Hoeffding, Lisette Kogelman, Thilde Marie Haspang, Henrik Ullum, Erik Sørensen, Christian Erikstrup, Ole Birger Pedersen, Kaspar René Nielsen, Henrik Hjalgrim, Helene M. Paarup, Thomas Werge, and Kristoffer Burgdorf, “Comorbidity of migraine with ADHD in adults,” BMC Neurology (2018), 18:147

Is There A Relationship Between ADHD And Migraines?

Stephen V. Faraone, PhD on October 18, 2018

A Danish team recruited 29,489 participants from among voluntary blood donors between the ages of 17 and 67, ensuring a large sample size. Participants were asked to complete two simple questionnaires on digital tablets. One asked two questions: “Have you ever had migraine?” and “Have you ever had visual disturbances lasting 5-60 min followed by headache?” A yes to either was considered positive for migraine. The other used the ADHD Self-Report Scale, with 18 ADHD symptoms evaluated on a five-point scale.

Excluding those who did not answer all questions left 26,456 participants. The risk for migraines among those with ADHD was nearly twice the risk for others. The odds ratio (OR) was 1.8, with a 95 percent confidence interval from 1.53 to 2.12 (p < 0.001). The OR was higher among females (2.01) than males (1.64). For those with visual disturbances, the OR was higher (1.98) than for those without (1.52). The association disappeared in those over 60, with an OR essentially equal to one (0.98, 95% CI = 0.84 – 1.15, p = 0.8).

Although the authors concluded, “We demonstrate a significant comorbidity between migraine and ADHD in adults, and this is most prominent for participants with migraine with visual disturbances,” the significance to which they refer are of the p-values, and should not be misinterpreted as an indication of a strong association, as the odds ratios point variably to weak, and weak-to-moderate associations, depending on subpopulations. The work is, however, important as it points to another somatic comorbidity of ADHD. That list is growing and now includes obesity, eczema and asthma.

REFERENCES
Thomas Folkmann Hansen, Louise K. Hoeffding, Lisette Kogelman, Thilde Marie Haspang, Henrik Ullum, Erik Sørensen, Christian Erikstrup, Ole Birger Pedersen, Kaspar René Nielsen, Henrik Hjalgrim, Helene M. Paarup, Thomas Werge, and Kristoffer Burgdorf, “Comorbidity of migraine with ADHD in adults,” BMC Neurology (2018), 18:147.

Social and Self-stigmatization in Adults with ADHD

Stephen V. Faraone, PhD on October 11, 2018

A German team recruited 104 adults with ADHD at both inpatient and outpatient ADHD clinics, and from ADHD self-help groups. Just under two-thirds were being treated with ADHD drugs, most with methylphenidate.

Just under a quarter reported high internalized stigma. Two in five reported high levels of alienation, meaning a sense of “not being a fully functioning, valuable member of society.” Three in ten reported high levels of social withdrawal.

On the other hand, only two participants reported high levels of stereotype endorsement, meaning personal acceptance of stereotypes associated with mental illness. And more than two-thirds reported high stigma resistance, meaning they were internally resistant to stigmatization. Thus, while most were free of significant internalized stigma, a still substantial minority were not.

Most of the participants expected to be discriminated against and treated unfairly by employers, colleagues at work, neighbors, and teachers should they reveal that they have ADHD. Relatively few expected to be discriminated against by health professionals, family, and friends. Almost half expected discrimination if they confided to strangers they were dating.

Over two-thirds of participants reported they had encountered public stereotypes concerning ADHD. But, on balance, they rated these at low levels of intensity. Nevertheless, among those perceiving such stereotypes, eight out of nine sensed some degree of public doubt about the validity of ADHD as a genuine ailment (“ADHD does not exist in adults”), and three out of four had at some point encountered the argument that “ADHD is invented by drug companies.” More than four out of five had heard allegations that ADHD results from bad parenting, and almost three in four had heard the claim that it results from watching too much television or playing too many video games.

These data call for more education of the public about the nature and causes of ADHD. Information reduces stigmatization so the widespread dissemination of the facts about ADHD is warranted.

REFERENCES

Theresa Vera Masuch, Myriam Bea, Barbara Alm, Peter Deibler, Esther Sobanski, “Internalized stigma, anticipated discrimination and perceived public stigma in adults with ADHD,” ADHD Attention Deficit and Hyperactivity Disorders (2018), doi.org/10.1007/s12402-018-0274-9.

ADHD Is A Risk Factor For Type Two Diabetes And High Blood Pressure, As Well As Other Psychiatric Disorders

Stephen V. Faraone, PhD on October 4, 2018

All Swedish residents have their health records tracked through unique personal identity numbers. That makes it possible to identify psychiatric and medical disorders with great accuracy across an entire population, in this case encompassing more than five and a half million adults aged 18 to 64. A subgroup of more than 1.6 million persons between the ages of 50 and 64 enabled a separate examination of disorders in older adults.

Slightly over one percent of the entire population (about 61,000) were diagnosed with ADHD at some point as an adult. Individuals with ADHD were nine times as likely to suffer from depression as were adults not diagnosed with ADHD. They were also more than nine times as likely to suffer from anxiety or a substance use disorder, and twenty times as likely to be diagnosed with bipolar disorder. These findings are very consistent with reports from clinical samples in the USA and Europe.

Adults with ADHD also had elevated levels of metabolic disorders, being almost twice as likely to have high blood pressure, and more than twice as likely to have type 2 diabetes. Persons with ADHD but without psychiatric comorbidities were also almost twice as likely to have high blood pressure, and more than twice as likely to have type 2 diabetes.

Similar patterns were found in men and women with ADHD, although comorbid depression, bipolar disorder, and anxiety were moderately more prevalent in females than in males, whereas substance use disorder, type 2 diabetes, and hypertension were more prevalent in males than in females.

ADHD was less than a third as prevalent in the over-50 population as in the general adult population. Nevertheless, individuals in this older group with ADHD were twelve times as likely to suffer from depression, anxiety, or substance use disorders, and more than 23 times as likely to be diagnosed with bipolar disorder as their non-ADHD peers. They were also 63% more likely to have high blood pressure, and 72% more likely to have type 2 diabetes.

The authors noted, “Although the mechanisms underlying these associations are not well understood, we know from both epidemiologic and molecular genetic studies that a shared genetic predisposition might account for the co¬existence of two or more psychiatric conditions. In addition, individuals with ADHD may experience increased difficulties as the demands of life increase, which may contribute to the development of depression and anxiety.” As for associations with hypertension and type 2 diabetes, these “might reflect health ¬risk behaviors among adult patients with comorbid ADHD in addition to a shared biological substrate. As others have noted, inattention, disinhibition, and disorganization associated with ADHD could make it difficult for patients to adhere to treatment regimens for metabolic disorders.” They concluded that “Clinicians should remain vigilant for a wide range of psychiatric and metabolic problems in ADHD affected adults of all ages and both sexes.”

REFERENCES

Qi Chen, Catharina A. Hartman, Jan Haavik, Jaanus Harro, Kari Klungsøyr, Tor¬Arne Hegvik, Rob Wanders, Cæcilie Ottosen, Søren Dalsgaard, Stephen V. Faraone, Henrik Larsson, “Common psychiatric and metabolic comorbidity of adult attention-deficit/hyperactivity disorder: A population-based cross-sectional study,” PLoS ONE (2018), 13(9): e0204516. https://doi.org/10.1371/journal.pone.0204516.

What Do We Know About the Relationship Between Omega-3 PUFAs and ADHD?

Stephen V. Faraone, PhD on September 27, 2018

There has been much interest in omega-3 Polyunsaturated fatty acids (PUFAs) as treatments for ADHD. Humans are unable to synthesize omega-3 PUFA alpha-linolenic acid (ALA) and the omega-6 PUFA linoleic acid (LA), and must therefore obtain these through food, which is why they are known as essential fatty acids. Because cells in the brain need omega-3 PUFAs, they have been studied as a treatment for ADHD by many researchers. In fact, several meta-analyses are available.

A 2014 meta-analysis by Elizabeth Hawkey and Joel Nigg combined nine studies involving 586 participants. It found mean blood levels of omega-3 PUFAs in persons with ADHD to be lower than in controls. The standardized mean difference (SMD) effect size was medium (SMD = .42, 95% CI = .26-.59), with less than a one in one thousand probability of such a result being obtained by chance alone. Adjusting for publication bias reduced the effect size slightly to .36 with a 95% CI of .21-.51, in the small-to-medium range. The authors then examined whether omega-3 supplementation could help alleviate ADHD symptoms. Combining 16 studies with 1,408 participants, they found improvements, but this time with a small effect size (SMD = .26, 95% CI = .15-.37), again with less than a one in a thousand probability of such a result being observed by chance. Adjusting for publication bias reduced the effect size to .16 with a 95% CI of .03-.28. For comparison, the SMD for stimulants is about 0.9.

Another meta-analysis conducted in the same year by Basant Puri and Julian Martins combined 18 PUFA supplementation studies involving 1,640 participants. They also found a small effect size for reduced ADHD symptoms (SMD = .19, 95% CI = .09-.30, p<.001). Adjusting for publication bias further reduced the effect size to a paltry and statistically insignificant level (SMD = .12, 95% CI = -.01-.25). It should be noted that while 16 of the studies involved omega-3 supplementation, two involved only omega-6 supplementation. Yet the results for the latter did not differ noticeably from the former. When the authors limited the analysis to the 11 studies specifically including both the omega-6 GLA and the omega-3 EPA, the effect size for reducing inattention symptoms was a bit higher (SMD = .31, 95% CI = .16-.46, p<.0001). But the results were not significantly different than those for the studies without the GLA+ALA combination (.012; 95% CI: .161-.137; p=.875). Publication bias was not addressed, and the hunt for a highly specific subset with positive results may have produced a false positive finding. The authors conceded, “Weaknesses of this study include the following: although the pooled effect was statistically significant, only two studies showed a significant effect by themselves; the funnel plot showed evidence of publication bias; there was evidence of reporting bias; few studies were formally registered; study methodological quality was variable; and the placebo used across studies varied.”

A 2016 meta-analysis by Laura Lachance et al. tried looking for differences in the ratio of omega-6 to omega-3 PUFAs, and more specifically, AA to EPA, in the blood of persons with ADHD versus normally developing persons. Pooling five studies with 485 participants, it found the omega-6 to omega-3 ratio to be significantly higher in persons with ADHD, and pooling three studies with 279 participants, it likewise found the AA to EPA ratio significantly higher.

A 2017 meta-analysis by Jane Pei-Chen Chang et al. reexamined comparative levels of omega-3 PUFAs in ADHD patients versus normally developing controls. Combining six studies with 396 participants, ADHD patients had lower levels in blood and mouth tissue, with a medium effect size (SMD = .38) that was not statistically significant (p=.14). Omega-6 levels were indistinguishable (SMD = .03) in the two groups. AA (SMD = .18, p=.33) and EPA (SMD = .25, p=.17) levels were slightly lower, but once again statistically not significant. DHA levels were lower as well, this time with a medium effect size (SMD = .56), but at the outer margin of significance (p=.05). Only by dropping one study were the authors able to claim significance for EPA, AA, and omega-3 differences.

Chang et al. also performed a meta-analysis of supplementation studies. Combining seven studies with 534 participants, they found a small to medium reduction in ADHD symptoms with omega-3 supplementation (SMD = .38, 95% CI = .2-.56, p<.0001). Corrections for publication bias were not reported. The authors also reported large reductions in both omission errors (SMD = 1.09, 95% CI = .43-.1.75, p<.001) and commission errors (SMD = 2.14, 95% CI = 1.24-3.03, p<.00001) on a neuropsychological test of attention. But the former involved only 3 studies with 214 participants, and the latter only two studies with 85 participants.

Also in 2017, Pelsser et al. published a systematic review that identified only two meta-analyses of double-blind, placebo-controlled trials of PUFA supplementation. One of those, a 2012 meta-analysis by Gillies et al., found no statistically significant declines in either parent-rated ADHD symptoms (five trials, 413 participants, SMD = -.17, 95% CI = -.38-.03) or teacher-rated ADHD symptoms (four trials, 324 participants, SMD = .05, 95% CI = -.18-.27). The other, a 2013 meta-analysis by Sonuga-Barke et al., found only a slight and barely statistically significant reduction in symptoms (11 trials, 827 participants, SMD = .16, 95% CI = .01-.31). Pelsser et al. concluded, “Considering the small average ESs PUFA supplementation is unlikely to provide a tangible contribution to ADHD treatment.”

Putting all of this together, there are indications that individuals with ADHD may have lower levels of omega-3 PUFAs, and that omega-3 supplementation may slightly reduce symptoms of ADHD, but the evidence remains inconclusive, with at best small effect sizes. It is possible, but not yet demonstrated, that omega-3 PUFAs might produce good outcomes in a small subset of patients.

REFERENCES

Jane Pei-Chen Chang, Kuan-Pin Su, Valeria Mondelli, and Carmine M Pariante, “Omega-3 Polyunsaturated Fatty Acids in Youths with Attention Deficit Hyperactivity Disorder: a Systematic Review and Meta-Analysis of Clinical Trials and Biological Studies,” Neuropsychopharmacology (2017), 43(3): 534–545.

Donna Gillies, John KH Sinn, Sagar S Lad, Matthew J Leach, Melissa J Ross, “Polyunsaturated fatty acids (PUFA) for attention deficit hyperactivity disorder (ADHD) in children and adolescents,” Cochrane Database of Systematic Reviews (2012), DOI:10.1002/14651858.CD007986.pub2.

Elizabeth Hawkey and Joel T. Negg, “Omega−3 fatty acid and ADHD: Blood level analysis and meta-analytic extension of supplementation trials,” Clinical Psychology Review (2014), 34(6), 496-505.

Laura LaChance, Kwame McKenzie, Valerie H. Taylor, and Simone N. Vigod, “Omega-6 to Omega-3 Fatty Acid Ratio in Patients with ADHD: A Meta-Analysis,” Journal of the Canadian Academy of Child and Adolescent Psychiatry (2016), 25(2), 87-96.

 

Lidy M. Pelsser, Klaas Frankena, Jan Toorman, Rob Rodrigues Pereira, “Diet and ADHD, Reviewing the Evidence: A Systematic Review of Meta-Analyses of Double-Blind Placebo-Controlled Trials Evaluating the Efficacy of Diet Interventions on the Behavior of Children with ADHD,” PLOS ONE (January 25, 2017), 1-25.

 

Basant K. Puri and Julian G. Martins, “Which polyunsaturated fatty acids are active in children with attention-deficit hyperactivity disorder receiving PUFA supplementation? A fatty acid validated meta-regression analysis of randomized controlled trials,” Prostaglandins, Leukotrienes and Essential Fatty Acids (2014), 90, 179-189.

Edmund J.S. Sonuga-Barke et al., “Nonpharmacological Interventions for ADHD: Systematic Review and Meta-Analyses of Randomized Controlled Trials of Dietary and Psychological Treatments,” American Journal of Psychiatry (2013), 170:275-289.

Guidelines for Screening, Diagnosing, and Managing ADHD in Children with Epilepsy

Stephen V. Faraone, PhD on September 20, 2018

A working group of the International League Against Epilepsy (ILAE), consisting of twenty experts spanning the globe (U.S., U.K., France, Germany, Japan, India, South Africa, Kenya, Brazil), recently published a “consensus paper” summarizing and evaluating what is currently known about comorbid epilepsy with ADHD, and best practices.

ADHD is two to five times more prevalent among children with epilepsy. The authors suggest that ADHD is underdiagnosed in children with epilepsy because its symptoms are often attributed either to epilepsy itself, or to the effects of antiepileptic drugs (AEDs).

The working group did a systematic search of the English-language research literature. It then reached consensus on practice recommendations, graded on the strength of the evidence.

Three recommendations were graded A, indicating they are well-established by evidence:

  • Children with epilepsy with comorbid intellectual and developmental disabilities are at increased risk of ADHD.
  • There is no increased risk of ADHD in boys with epilepsy compared to girls with epilepsy.
  • The anticonvulsant valproate can exacerbate attentional issues in children with childhood absence epilepsy (absence seizures look like staring spells during which the child is not aware or responsive). Moreover, a single high-quality population-based study indicates that valproate use during pregnancy is associated with inattentiveness and hyperactivity in offspring.

Four more were graded B, meaning they are probably useful/predictive:

  • Poor seizure control is associated with increased risk of ADHD.
  • Data support the ability of the Strengths and Difficulties Questionnaire (SDQ) to predict ADHD diagnosis in children with epilepsy: “Borderline or abnormal SDQ total scores are highly correlated with the presence of a validated psychiatric diagnosis (93.6%), of which ADHD is the most common (31.7%).” The SDQ can therefore be useful as a screening tool.
  • Evidence supports the efficacy of methylphenidate in children with epilepsy and comorbid ADHD.
  • Methylphenidate is tolerated in children with epilepsy.

At the C level of being possibly useful, there is limited evidence that supports that atomoxetine is tolerated in children with ADHD and epilepsy, and that the combined use of drugs for ADHD and epilepsy (polytherapy) is more likely to be associated with behavioral problems than monotherapy. In the latter instance, “Studies are needed to elucidate whether the polytherapy itself has resulted in the behavioral problems, or the combination of polytherapy and the underlying brain problem reflects difficult‐to‐control epilepsy, which, in turn, has resulted in the prescription of polytherapy.”

All other recommendations were graded U (for Unproven), “Data inadequate or conflicting; treatment, test or predictor unproven.” These included three where the evidence is ambiguous or insufficient:

  • Evidence is conflicted for the impact of early seizure onset on the development of ADHD in children with epilepsy.
  • Tolerability for amphetamine in children with epilepsy is not defined.
  • Limited evidence exists for the efficacy of atomoxetine and amphetamines in children with epilepsy and ADHD.

There were also nine U-graded recommendations based solely on expert opinion. Most notable among these:

  • Screening children with epilepsy for ADHD beginning at age 6.
  • Reevaluation of attention function after any change in antiepileptic drug.
  • Screening should not be done within 48 hours following a seizure.
  • ADHD should be distinguished from childhood absence epilepsy based on history and an EEG with hyperventilation.
  • Multidisciplinary involvement in transition and adult ADHD clinics is essential as many patients experience challenges with housing, employment, relationships, and psychosocial well‐being.

REFERENCES

Stéphane Auvin et al., “Systematic review of the screening, diagnosis, and management of ADHD in children with epilepsy. Consensus paper of the Task Force on Comorbidities of the ILAE Pediatric Commission,” Epilepsia (2018), doi: 10.1111/epi.14549. .

How Can Women Best Manage ADHD During Pregnancy to Minimize Risk to their Babies?

Stephen V. Faraone, PhD on September 13, 2018

Roughly one in thirty adult women have ADHD. Research results indicate that psychostimulants (methylphenidate and amphetamines) offer the most effective course of treatment in most instances. But during pregnancy, such treatment also exposes the fetus to these drugs.

Several studies have set out to determine whether such exposure is harmful. The largest compared 5,571 infants exposed to amphetamines and 2,072 exposed to methylphenidate with unexposed infants. It found no increased risks for adverse outcomes due to amphetamine or methylphenidate exposures.

Another study studied 3,331 infants exposed to amphetamines, 1,515 exposed to methylphenidate, and 453 to atomoxetine. Comparing these infants to unexposed infants, it found a slightly increased risk of preeclampsia, with an adjusted risk ratio of 1.29 (95% CI 1.11-1.49), but no statistically significant effect for placental abruption, small gestational age, and preterm birth. When assessing the two stimulants, amphetamine and methylphenidate, together, it found a small increased risk of preterm birth, with an adjusted risk ratio of 1.3 (95% CI 1.10-1.55). There was no statistically significant effect for preeclampsia, placental abruption, or small gestational age. Atomoxetine use was free of any indication of increased risk.

Another study involving 1,591 infants exposed to ADHD medication (mostly methylphenidate) during pregnancy, reported increased risks associated with exposure. The adjusted odds ratio for admission to a neonatal intensive care unit was 1.5 (95% CI 1.3-1.7), and for central nervous system disorders was 1.9 (95% CI 1.1-3.1). There was no increased risk for congenital malformations or perinatal death.

Six studies focused on methylphenidate exposure. Two, with a combined total of 402 exposed infants, found no increased risk for malformations. Another, with 208 exposed infants, found a slightly greater risk of cardiovascular malformations, but it was not statistically significant. A fourth, with 186 exposed infants, found no increased risk of malformations, but did find a higher rate of miscarriage, with an adjusted hazard ratio of 1.98 (95% CI 1.23-3.20). A fifth, with 480 exposed infants, also found a higher rate of miscarriage, with an odds ratio of 2.07 (95% CI 1.51-2.84). But although the sixth, with 382 exposed infants, likewise found an increased risk of miscarriage (adjusted relative risk 1.55 with 95% CI 1.03-2.06), it also found an identical risk for women with ADHD who were not on medication during their pregnancies (adjusted relative risk 1.56 with 95% CI 1.11-2.20). That finding suggests that all women with ADHD have a higher risk of miscarriage, and that methylphenidate exposure is not the causal factor.

Summing up, while some studies have shown increased adverse effects among infants exposed to maternal ADHD medications, most have not. There are indications that higher rates of miscarriage are associated with maternal ADHD rather than fetal exposure to psychostimulant medications. One study did find a small increased risk of central nervous system disorders and admission to a neonatal intensive care unit. But, again, we do not know whether that was due to exposure to psychostimulant medication, or associated with maternal ADHD.

If there is a risk, it appears to be a small one. The question then becomes how to balance that as yet uncertain risk against the disadvantage of discontinuing effective psychostimulant medication. As the authors of this review conclude:

It is associated with significant psychiatric comorbidities for women, including depression, anxiety, substance use disorders, driving safety impairment, and occupational impairment. The gold standard treatment includes behavioral therapy and stimulant medication, namely methylphenidate and amphetamine derivatives. Psychostimulant use during pregnancy continues to increase and has been associated with a small increased relative risk of a range of obstetric concerns. However, the absolute increases in risks are small, and many of the best studies to date are confounded by other medication use and medical comorbidities. Thus, women with moderate-to-severe ADHD should not necessarily be counseled to suspend their ADHD treatment based on these findings.

They advise that when functional impairment from ADHD is moderate to severe, the benefits of stimulant medications may outweigh the small known and unknown risks of medication exposure, and that “If a decision is made to take ADHD medication, women should be informed of the known risks and benefits of the medication use in pregnancy, and take the lowest therapeutic dose possible.”

 

REFERENCES

Allison S. Baker, Marlene P. Freeman, “Management of Attention Deficit Hyperactivity Disorder During Pregnancy,” Obstetrics and Gynecology Clinics of North America, vol. 45, issue 3 (2018), 495-509.

Immediate and Longer-Term Effects of Exercise on ADHD Symptoms and Cognition

Stephen V. Faraone, PhD on September 6, 2018

A team of Spanish researchers has published a systematic review of 16 studies with a total of 728 participants exploring the effects of physical exercise on children and adolescents with ADHD. Fourteen studies were judged to be of high quality, and two of medium quality.

Seven studies looked at the acute effects of exercise on eight to twelve-year-old youths with ADHD. Acute means that the effects were measured immediately after periods of exercise lasting up to 30 minutes. Five studies used treadmills and two used stationary bicycles, for periods of five to 30 minutes. Three studies “showed a significant increase in the speed reaction and precision of response after an intervention of 20–30 min, but at moderate intensity (50–75%).” Another study, however, found no improvement in mathematical problem solving after 25 minutes using a stationary bicycle at low (40–50%) or moderate intensity (65–75%). The three others found improvements in executive functioning, planning, and organization in children after 20- to 30-minute exercise sessions.

Nine studies examined longer-term effects, following regular exercise over a period of many weeks. One reported that twenty consecutive weekly yoga sessions improved attention. Another found that moderate to vigorous physical activity (MVPA) led to improved behavior beginning in the third week, and improved motor, emotional and attentional control, by the end of five weeks. A third study reported that eight weeks of starting the school day with 30 minutes of physical activity led to improvement in Connors ADHD scores, oppositional scores, and response inhibition. Another study found that twelve weeks of aerobic activity led to declines in bad mood and inattention. Yet another reported that thrice-weekly 45-minute sessions of MVPA over a ten-week period improved not only muscle strength and motor skills, but also attention, response inhibition, and information processing.

Two seventy-minute table tennis per week over a twelve-week period improved executive functioning and planning in addition to locomotor and object-control skills.

Two studies found a significant increase in brain activity. One involved two hour-long sessions of rowing per week for eight weeks, the other three 90-minute land-based sessions per week for six weeks. Both studies measured higher activation of the right frontal and right temporal lobes in children, and lower theta/alpha ratios in male adolescents.

All 16 studies found positive effects on cognition. Five of the nine longer-term studies found positive effects on behavior. No study found any negative effects. The authors of the review concluded that physical activity “improves executive functions, increases attention, contributes to greater planning capacity and processing speed and working memory, improves the behavior of students with ADHD in the learning context, and consequently improves academic performance.” Although the data are limited by lack of appropriate controls, they suggest that, in addition to the well-known positive effects of physical activity, one may expect to see improvements in ADHD symptoms and associated features, especially for periods of sustained exercise.

REFERENCES

Sara Suarez-Manzano, Alberto Ruiz-Ariza, Manuel De La Torre-Cruz, Emilio J. Martínez-López, “Acute and chronic effect of physical activity on cognition and behaviour in young people with ADHD: A systematic review of intervention studies,” Research in Developmental Disabilities, vol. 77, 12-23 (2018).

How Reliable are Subjective Estimates of ADHD Medication Adherence?

Stephen V. Faraone, PhD on August 30, 2018

A study conducted at Auburn University in Alabama recruited 54 college students to address this question. All had previously been diagnosed with ADHD. All lived independently, and all were taking a prescribed ADHD medication. Students with severe comorbid psychiatric conditions were excluded. Three students dropped out, leaving a final sample size of 51.

Each student completed a total of four half-hour assessments, scheduled at monthly intervals. At each first assessment, researchers counted the participant’s ADHD medication pills and transferred them to an electronic monitoring bottle – a bottle with a microchip sensor in the cap that automatically tracks the date and time of every opening. This enabled them to compare students’ subjective estimates at subsequent assessments with the objective evidence from pill counts and from the data output from the electronic monitoring bottles.

Overall, students reported missing about one in four (25 percent) of their prescribed doses. But the objective measures showed they were in fact skipping closer to half their doses. According to pill counts they were missing 40 percent of their doses, and according to the electronic monitoring bottles, 43 percent. The odds of obtaining such a result due to chance with a sample of size were less than one in a hundred (p < 0.01).

In other words, college students with ADHD significantly overestimate their adherence rates to their medications. The authors concluded, “without additional strategies in place, expecting adolescents and young adults with ADHD to remember a daily task that requires no more than a few seconds to accomplish, such as medication taking, is unrealistic.” They suggest using smartphone reminder applications (“apps”) and text messaging services.

The authors caution that this was the first such study, and that it had a small sample size. Moreover, the study was not randomized. Students responded to advertisements posted on campus, and thus self-selected.

Pending the outcome of larger studies with randomization, the authors suggest that wherever possible, prescribing physicians adopt objective measures of medication adherence, as an aid to ensuring greater efficacy of treatment.

REFERENCES

Megan R. Schaefer, Scott T. Wagoner, Margaret E. Young, Alana Resmini Rawlinson, Jan Kavookjian, Steven K. Shapiro, Wendy N. Gray, “Subjective Versus Objective Measures of Medication Adherence in Adolescents/Young Adults with Attention-Deficit Hyperactivity Disorder,” Journal of Developmental & Behavioral Pediatrics, Published online July 11, 2018, DOI: 10.1097/DBP.0000000000000602.