Maternal Smoking During Pregnancy and ADHD: Results From a Systematic Review and Meta-Analysis of Prospective Cohort Studies

Yan He, Jian Chen, Li-Hua Zhu, Ling-Ling Hua, and Fang-Fang Ke

Journal of Attention Disorders 1 –11 , 2017 DOI: 10.1177/1087054717696766

This article describes a meta-analyses of studies which examined the potential effects of maternal smoking on the risk of childhood ADHD. A prior meta-analysis in 2005 (Langley, Rice, Van den Bree, & Thapar, 2005) found a strong association between maternal smoking and subsequent development of childhood ADHD in exposed offspring. Several recent individual studies also found an association be, tween maternal smoking and childhood ADHD, but one prospective study (Ball et al., 2010) did not find such an association. Therefore, given the length of time since the last meta-analysis and the one negative study noted above, highlighted the need for an updated meta-analysis. The authors employed fairly standard meta-analysis guidelines via the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement, which included a selection of studies, data extraction and assessment of study quality. The risk ratios (RRs) and 95% CIs reported in the individual studies were pooled across studies to examine the potential association of maternal smoking during pregnancy and childhood ADHD risk. The authors also examined for presence of publication bias and changing association over time. 265 studies were originally identified, with 12 meeting the stringent criteria to be included in the meta-analysis. The main finding of the analysis was the maternal smoking was modestly association with an increased risk of ADHD in children (pooled RR = 1.58, 95% CI = ) and this association seemed to increase over time (by examining publication year); no significant publication bias was seen. The authors that the association they observed was not as robust as the one seen by Langley et al. for several reasons: their including a larger number of trials, which were limited to those with prospective and not case-controlled desi This meta-analysis is important for clinicians as it highlights the importance of the need to caution their patients as to potential risks of offspring developing ADHD in mothers who smoke during pregnancy.

REFERENCES:
Ball, S. W., Gilman, S. E., Mick, E., Fitzmaurice, G., Ganz, M. L., Seidman, L. J., & Buka, S. L. (2010). Revisiting the association between maternal smoking during pregnancy and ADHD. Journal of Psychiatric Research, 44, 1058-10

Langley, K., Rice, F., Van den Bree, M. B., & Thapar, A. (2005). Maternal smoking during pregnancy as an environmental risk factor for attention deficit hyperactivity disorder behaviour. A review. Minerva Pediatrica, 57, 359-37

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

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.

Is Prenatal Antidepressant Exposure a Risk Factor for ADHD?

A systematic review of the literature found seven studies examining this question. Significantly, six were large cohort studies with a combined total of almost three million individuals. The other was a large case-control study with 7,874 participants.

The largest cohort study, with more than a million and a half children, found that prenatal antidepressant exposure increased the risk for ADHD. The adjusted odds ratio was 1.6 for any antidepressant and for selective serotonin reuptake inhibitors (SSRI). But in sibling comparison models, which better adjust for confounds shared by siblings (e.g., poverty, stress in the home), this study found no increased risk of ADHD.

The second largest cohort study, with over 875 thousand children, found a small adjusted risk of 1.2 for all antidepressants, with little variation by class of antidepressant. The fourth largest study, with over 140 thousand children, likewise found a small adjusted risk of 1.2, which barely achieved statistical significance (95% CI 1.0-1.4).

The third largest study, with over 190 thousand children, obtained an adjusted risk of 1.4 for all antidepressants. But it also pointed to a possible explanation for the small association found in this and other studies suggesting that the apparent association with antidepressant use was due to ADHD’s known genetic association with psychiatric conditions treated by antidepressants.

The fifth largest study, with more than 55 thousand children, similarly found an adjusted risk of 1.7 for SSRIs and an adjusted risk of 1.7 for unmedicated maternal psychiatric disorder. Again, the underlying psychiatric disorder appears to be confounding the effect of antidepressants.

The sixth largest study, with over 38 thousand children, found no evidence of any effect from SSRIs. Yet it found evidence of a large effect from bupropion, with an odds ratio of 3.6, and only one in 50 odds of obtaining such a result by chance (p = 0.02). However, it offered no comparison with untreated depression, and made no adjustments for potential confounders.

The case control study found an odds ratio of 2.3 for maternal use of any antidepressant, which dropped to a statistically nonsignificant 1.6 when adjusted for maternal psychiatric disorder (95% CI 0.66-3.71).

The review concludes, “The evidence available is inadequate to indicate any negative effects of a specific class of antidepressant on the risk of ADHD.”

REFERENCES
Faruk Uguz, “Maternal Antidepressant Use During Pregnancy and the Risk of Attention-Deficit/Hyperactivity Disorder in Children: A Systematic Review of the Current Literature,” Journal of Clinical Psychopharmacology, vol. 38, no. 3 (2018).

Is Prenatal Exposure to Bisphenol A (BPA) Associatd with Childhood ADHD?

A team of U.S. endocrinologists recently published the results of a meta-analysis examining a possible association between bisphenol A (BPA) and childhood ADHD. BPA is used in a variety of consumer products, including plastic bottles for food and drink, epoxy resins used to line cans of food, dental sealants, and the thermal receipts issued by stores.

A review of the literature found 29 rodent studies but only three with humans. The human studies were too different from each other to be suitable for meta-analysis. One found no association between prenatal exposure and ADHD. A second found prenatal BPA exposure to be associated with teacher-reported hyperactivity in 4-year-old boys, but not girls. The third found it to be associated with hyperactivity scores in 3-year-old girls.

As the authors note, “Often, there is little human data available, particularly in the environmental toxicology/health fields, due to the time and expense of conducting epidemiological studies and the ethical barriers for human controlled trials that involve human exposure to potentially hazardous chemicals. Thus, it is important to have methods for using animal data to inform human health hazard conclusions; indeed, animal models are traditionally used to study human health.”

Twelve of the mice and rat studies, with a total of 709 rodents, were suitable for meta-analysis.

Overall these pointed to a tiny SMD effect size of 0.09, but it was not significant, with the odds of such a result being obtained by chance being almost one in four (p = 0.237). But when results from the 356 males and 353 females were looked at separately, a significant sex difference emerged. There was essentially no effect on female rodents, with an effect size of -0.07 and a 95% confidence interval of -0.27 to 0.14, widely spanning the zero mark, rendering the result statistically nonsignificant. Among male rodents, however, there was a small but statistically significant effect size (0.24), with a 95% confidence interval from 0.04 to 0.45. The odds of obtaining this outcome by chance were only one in 50 (p = .02).

This result must be viewed with caution, as rodent physiology often differs substantially from that of humans. The authors therefore conclude, “early BPA exposure is associated with a presumed hazard of hyperactivity in humans. Our conclusion is based on ‘moderate’ levels of evidence for the human and ‘high’ levels of evidence for animal literature.”

REFERENCES
Johanna R. Rochester, Ashley L. Bolden, Carol F. Kwiatkowski, “Prenatal exposure to bisphenol A and hyperactivity in children: a systematic review and meta-analysis,” Environment International, vol. 114, p. 343-356 (2018).

ADHD and Acetaminophen Use During Pregnancy

A recent CNN report, http://tinyurl.com/yannlfd6, highlighted a paper published in Pediatrics, which reported that pregnant women who use acetaminophen during pregnancy put their unborn child at two-fold increased risk for attention deficit hyperactivity disorder (ADHD).   In that study, acetaminophen use during pregnancy was common; nearly half of women surveyed used the painkiller during a pregnancy.   Other studies have reported similar associations of acetaminophen, also known as paracetamol with ADHD or with other problems in childhood (e.g., https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5300094/https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4177119/https://www.ncbi.nlm.nih.gov/pubmed/24566677https://www.ncbi.nlm.nih.gov/pubmed/24163279).

Given these prior findings, it seems unlikely that the new report is a chance finding. But does it make any biological sense?   One answer to that question came from an epigenetic study. Such studies figure out if assaults from the environment change the genetic code. One epigenetic study found that prenatal exposure, changes the fetal genome via a process called methylation. Such genomic changes could increase risk for ADHD (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5540511/)/ .

Because all of these studies are observational studies, one cannot assert with certainty that there is a causal link between acetaminophen use during pregnancy. The observed association could be due to some unmeasured third factor. Although the researchers did a respectable job ruling out some third factors, we must acknowledge some uncertainty in the finding. That said, what should pregnant women do if they need a acetaminophen.   I suggest you bring this information to your physician and ask if there is a suitable alternative.

Stimulant Medication and Psychotic Symptoms in Offspring of Parents With Mental Illness

Pediatrics 2016; 137(1);e20152486
“Stimulant Medication and Psychotic Symptoms in Offspring of Parents With Mental Illness”
MacKenzie, L.E., Abidi, S., Fisher, H.L. et al.

Treatment of ADHD with stimulant medications carries many known risks including the development of psychotic symptoms which is considered to be a rare adverse event. It is reported that between 0.25% – 1.5% of children taking stimulants develop psychotic symptoms. However, little is known about the nature of these symptoms or about the potential for higher rates of psychosis in at-risk populations such as the children of parents with serious mental illness (SMI). Case reports and a chart review report that the rate of stimulant-induced psychosis in this group ranges from 8% to 20%. The authors of this paper set out study the rates and types of psychotic symptoms in children with parents suffering SMIs such as major depression, bipolar disorder and schizophrenia. They carefully evaluated 141 children (ages 6-21 years, average 11.8 years) in a study of developmental psychopathology in offspring of parents with SMI in Nova Scotia entitled “Families Overcoming Risks and Building Opportunities for Wellbeing.” The study employed several standardized interviews to inquire into a variety of psychiatric conditions including the occurrence and the nature of psychotic symptoms experienced by these children. All youths and parents were interviewed using the Kiddie SADS and three other interviews that probe for prodromal syndromes, psychotic-like experiences and proneness to schizophrenia. The rates of psychotic symptoms were reported for the entire sample and the rates were compared between children receiving stimulant medications (N=24) and those who never took a stimulant. Moderators such as parental diagnosis and presence or absence of ADHD in the child were also analyzed.

Of the 24 children receiving stimulant medication, 15 (62.5%) developed psychotic and related symptoms compared with 32 (27.4%) of the remaining 117 participants who had never taken stimulants. The adjusted odds ratio for psychotic symptoms due to stimulant medication was found to be 4.41. Further analyses revealed a stronger effect of stimulant medication (OR: 4.51) and a very weak effect of ADHD (OR: 1.16) on the development of psychosis. No differences were seen in rates of psychosis when analyzing parental psychopathology. Psychotic symptoms were seen in 37.5% of children of parents with schizophrenia, 34% of parents with bipolar disorder and 32% of parents with major depressive disorder. All of the children with medication-induced psychosis had parents with either bipolar disorder or depressive disorder. By far, the most common psychotic symptoms reported were hallucinations. Lastly, a sensitivity analysis was conducted to determine the temporal relationship between stimulant treatment and the onset of psychotic symptoms. Of the 15 individuals with current stimulant use, 25% developed symptoms; of the 126 participants without current stimulant use, 5% were experiencing psychotic symptoms. The Odds Ratio of developing psychotic symptoms from stimulants was 7.25. Moreover, a subset of children clearly developed psychosis as a result of taking stimulants.

This study was extremely well designed and implemented. It is the first of its kind to carefully document the frequency and nature of psychotic symptoms in children of parents with SMI, and to quantify the considerable added risk to those prescribed stimulant medication. It convincingly demonstrates the substantial risk these children face and suggests that clinicians should be cautious whenever prescribing stimulant medications to this group, and should carefully monitor for the onset of serious adverse effects.

ADHD Parenting among ADHD Adults

Journal of Clinical Child and Adolescent Psychology. 2014. DOI: 10.1080/15374416.2014.963858

“The Role of Parental ADHD in Sustaining the Effects of a Family-School Intervention for ADHD”

Dawson, A.E., Wymbs, B.T., Marshall, S.A., Mautone, J.A., Power, T.J.

This paper reports on the extent to which parental ADHD impacts child and parent functional outcomes of a multimodal family-school intervention designed to boost academic performance of 139 school-aged children with ADHD.

The initial results of this randomized controlled trial (N = 199) comparing an experimental intervention, the Family School Success Program (FSS) to an active-control condition, Coping with ADHD through Relationships and Education (CARE), revealed that participants in each group showed gains in the primary targeted outcomes.

For children, these included rates of completing homework, academic productivity, and symptoms of ADHD and oppositional defiant disorder (ODD) as measured by the Swanson, Nolan and Pelham Questionnaire (SNAP).  Parental outcomes included parents’ view of their efficacy as their child’s educator, quality of the parent-teacher relationship, and quality of the parent-child relationship.  While both groups showed improvements, there were modest treatment effect sizes seen in the FSS group as compared to the CARE group in ratings of homework performance, self-reported parenting practices, and overall quality of school-family relationships (Power et al, 2012).

The last two outcomes were also better in the FSS group at a follow-up assessment conducted by the researchers three months after the conclusion of the study.

Given growing concern regarding the role that parental ADHD may play in moderating the effectiveness of treatments for children with ADHD (a topic that is thoroughly reviewed in the introduction section of this paper), these investigators went on to examine the impact of parental ADHD symptoms on the study’s outcomes.

Parental ADHD was determined by administering a self-report scale, the Conners’ Adult ADHD Rating Scale (CAARS) to 139 of the parent participants in the study.  Both dimensional and dichotomous ADHD variables were created but only the latter was used in the analysis because of the small size of the ADHD group (N = 23, or roughly 16% of the total).

Results showed that parental ADHD did not affect treatment outcome for either the experimental (FSS) or the control (CARE) condition at the end of the study period.  However, at the three month follow-up assessment, parental ADHD was associated with declines in treatment gains only in the FSS group, particularly in the quality of parent-teacher relationship and the child’s homework performance.  This finding surprised the investigators who hypothesized that ADHD parents in both groups would show declines in outcomes as compared to non-ADHD parents.

They concluded that the control condition may have provided ADHD parents with greater opportunities to develop strategies and to practice problem-solving skills on their own, whereas ADHD parents in the experimental condition might have become overly dependent on study clinicians to implement the parenting practices that were the focus of the intervention.

This study illustrates the importance of modifying parent-focused treatment interventions to the specific characteristics of the patient and family.  In particular, when parents of ADHD children also exhibit the symptoms of ADHD, it may be helpful to provide additional opportunities for them to develop strategies, cultivate resources, and practice parenting skills aimed at helping their ADHD children succeed at school.

CAARS = Conners’ Adult ADHD Rating Scale

CARE = Coping with ADHD through Relationships and Education

FSS = Family School Success Program

Power, T.J., Mautone, J.A., Soffer, S.L. Clarke, A.T., et al (2012). “A family-school intervention for children with ADHD: Results of a randomized clinical trial.” Journal of Clinical Child and Adolescent Psychology. 80: 611-623 DOI: 10.1037/a0028188.

ADHD Medication and Parenting

Raising children is not easy. I should know. As a clinical psychologist, I’ve helped parents learn the skills they need to be better parents. And my experience raising three children confirmed my clinical experience. Parenting is a tough job under the best of circumstances but it is even harder if the parent has ADHD. For example, an effective parent establishes rules and enforces them systematically. This requires attention to detail, self-control and good organizational skills. Given these requirements, it is easy to see how ADHD symptoms interfere with parenting. These observations have led some of my colleagues to test the theory that treating ADHD adults with medication would improve their parenting skills. I know about two studies that tested this idea. In 2008, Dr. Chronis-Toscano and colleagues published a study using a sustained release form of methylphenidate for mothers with ADHD. As expected, the medication decreased their symptoms of inattention and hyperactivity/impulsivity. The medication also reduced the mothers use of inconsistent discipline and corporal punishment and improved their monitoring and supervision of their children. In a 2014 study, Waxmonsky and colleagues observed ADHD adults and their children in a laboratory setting once when the adults were off medication and once when they were on medication. They used the same sustained release form of amphetamine for all the patients. As expected, the medications reduced ADHD symptoms in the parents. This laboratory study is especially informative because the researchers made objective ratings of parent-child interactions rather than relying on the parent’s report of those interactions. Twenty parents completed the study. The medication led to less negative talk and commands and more praise by parents. It also reduced negative and inappropriate behaviors in their children. Both studies suggest that treating ADHD adults with medication will improve their parenting skills. That is good news. But they also found that not all parenting behaviors improved. That makes sense. Parenting is a skill that must be learned. Because ADHD interferes with learning, parents with the disorder need time to learn these skills. Medication can eliminate some of the worst behaviors but doctors should also provide the adjunct behavioral or cognitive behavioral therapies that could help ADHD parents learn parenting skills and achieve their full potential as parents.
 

REFERENCES
Chronis-Tuscano, A., K. E. Seymour, et al. (2008). “Efficacy of osmotic-release oral system (OROS) methylphenidate for mothers with attention-deficit/hyperactivity disorder (ADHD): preliminary report of effects on ADHD symptoms and parenting.” J Clin Psychiatry 69(12): 1938-1947.
Waxmonsky, J. G., D. A. Waschbusch, et al. (2014). “Does pharmacological treatment of ADHD in adults enhance parenting performance? Results of a double-blind randomized trial.” CNS Drugs 28(7): 665-677.

Parental ADHD and FSS (Family School Success)

Journal of Clinical Child and Adolescent Psychology. 2014. DOI: 10.1080/15374416.2014.963858

“The Role of Parental ADHD in Sustaining the Effects of a Family-School Intervention for ADHD”

Dawson, A.E., Wymbs, B.T., Marshall, S.A., Mautone, J.A., Power, T.J.

This paper reports on the extent to which parental ADHD impacts child and parent functional outcomes of a multimodal family-school intervention designed to boost academic performance of 139 school-aged children with ADHD.   The initial results of this randomized controlled trial (N = 199) comparing an experimental intervention, the Family School Success Program (FSS) to an active-control condition, Coping with ADHD through Relationships and Education (CARE), revealed that participants in each group showed gains in the primary targeted outcomes.  For children, these included rates of completing homework, academic productivity, and symptoms of ADHD and oppositional defiant disorder (ODD) as measured by the Swanson, Nolan and Pelham Questionnaire (SNAP).  Parental outcomes included parents’ view of their efficacy as their child’s educator, quality of the parent-teacher relationship, and quality of the parent-child relationship.  While both groups showed improvements, there were modest treatment effect sizes seen in the FSS group as compared to the CARE group in ratings of homework performance, self-reported parenting practices, and overall quality of school-family relationships (Power et al, 2012).   The last two outcomes were also better in the FSS group at a follow-up assessment conducted by the researchers three months after the conclusion of the study.  

Given growing concern regarding the role that parental ADHD may play in moderating the effectiveness of treatments for children with ADHD (a topic that is thoroughly reviewed in the introduction section of this paper), these investigators went on to examine the impact of parental ADHD symptoms on the study’s outcomes.  Parental ADHD was determined by administering a self-report scale, the Conners’ Adult ADHD Rating Scale (CAARS) to 139 of the parent participants in the study.  Both dimensional and dichotomous ADHD variables were created but only the latter was used in the analysis because of the small size of the ADHD group (N = 23, or roughly 16% of the total).    Results showed that parental ADHD did not affect treatment outcome for either the experimental (FSS) or the control (CARE) condition at the end of the study period.  However, at the three month follow-up assessment, parental ADHD was associated with declines in treatment gains only in the FSS group, particularly in the quality of parent-teacher relationship and the child’s homework performance.  This finding surprised the investigators who hypothesized that ADHD parents in both groups would show declines in outcomes as compared to non-ADHD parents.   They concluded that the control condition may have provided ADHD parents with greater opportunities to develop strategies and to practice problem-solving skills on their own, whereas ADHD parents in the experimental condition might have become overly dependent on study clinicians to implement the parenting practices that were the focus of the intervention.  

This study illustrates the importance of modifying parent-focused treatment interventions to the specific characteristics of the patient and family.  In particular, when parents of ADHD children also exhibit the symptoms of ADHD, it may be helpful to provide additional opportunities for them to develop strategies, cultivate resources, and practice parenting skills aimed at helping their ADHD children succeed at school.

CAARS = Conners’ Adult ADHD Rating Scale

CARE = Coping with ADHD through Relationships and Education

FSS = Family School Success Program

 

Power, T.J., Mautone, J.A., Soffer, S.L. Clarke, A.T., et al (2012). “A family-school intervention for children with ADHD: Results of a randomized clinical trial.” Journal of Clinical Child and Adolescent Psychology. 80: 611-623 DOI: 10.1037/a0028188.