Preliminary Evidence of an Association Between ADHD Medications and Diminished Bone Health in Children and Adolescents

Psychostimulants prescribed to children for ADHD following distal radius fractures significantly reduce bone density as a function of duration

Methylphenidate and mixed amphetamine salts (MAS) are psychostimulant medications widely prescribed for various psychiatric disorders. Although these medications are known to adversely impact bone mineral content and density, as well as biomechanical integrity during skeletal development in rats, their effect on bone density in children remains largely unknown. The primary aim of this work was to investigate the effects of methylphenidate and MAS on bone density following distal radius fractures in pediatric populations, and secondarily assess any impact on healing. The retrospective case-control study was designed to assess fracture healing in patients treated with stimulant drugs and matched controls. For the primary outcome, X-rays ( n  = 188) were evaluated using an optical density image analysis technique to compare bone density throughout the bone healing process. Results showed that methylphenidate and MAS significantly reduced bone healing by approximately 20% following distal radius fractures in these children. The data also suggested that duration of psychostimulant use played a role in bone healing; the longer the treatment (1-5 years), the lower the bone density was observed (by approximately 52%) as compared to controls (no medication). However, subjects taking these drugs for longer than 5 years did not show a significant difference. Our results suggested that children taking psychostimulants for up to 5 years had slower bone healing following distal radius fractures. Orthopedic surgeons planning elective surgeries should be cognizant of this as a potential issue in recovery after any elective bone procedures and preoperatively optimize bone health as well as counsel patients and their families.

The Impact of Methylphenidate on Pubertal Maturation and Bone Age in ADHD Children and Adolescents: Results from the ADHD Drugs Use Chronic Effects (ADDUCE) Project

OBJECTIVE

The short-term safety of methylphenidate (MPH) has been widely demonstrated; however the long-term safety is less clear. The aim of this study was to investigate the safety of MPH in relation to pubertal maturation and to explore the monitoring of bone age.

METHOD

Participants from ADDUCE, a two-year observational longitudinal study with three parallel cohorts (MPH group, no-MPH group, and a non-ADHD control group), were compared with respect to Tanner staging. An Italian subsample of medicated-ADHD was further assessed by the monitoring of bone age.

RESULTS

The medicated and unmedicated ADHD groups did not differ in Tanner stages indicating no higher risk of sexual maturational delay in the MPH-treated patients. The medicated subsample monitored for bone age showed a slight acceleration of the bone maturation after 24 months, however their predicted adult height remained stable.

CONCLUSION

Our results do not suggest safety concerns on long-term treatment with MPH in relation to pubertal maturation and growth.

Breaking It Down: A Systematic Review Unravelling the Impact of Attention Deficit Hyperactivity Disorder and Methylphenidate on Childhood Fractures

Limb fractures are a common cause of pediatric hospital admissions and surgeries, with a significant prevalence in the United Kingdom across all injury categories. Among psychiatric conditions in children, attention deficit hyperactivity disorder (ADHD) stands out as frequently associated with fractures, particularly those involving extremities. ADHD, with diagnoses prevalent among a significant proportion of school-age children and adolescents, has witnessed a growing global incidence. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 checklist for our systematic literature search, using various databases and specific search terms related to ADHD and fractures. We considered articles from 2018 to 2023, focusing on English language papers with free full-text access. Our selection process used the PRISMA flowchart. We began with 1,890 articles and, after deduplication, title screening, abstract assessment, and quality evaluation included nine research papers in our review. Our primary focus was on examining fracture-related outcomes in individuals with ADHD compared to those without, considering medication status. These studies encompassed various designs, with a focus on the ADHD-fracture relationship and methylphenidate's (MPH) impact. Our study confirms that ADHD increases fracture risk and suggests that MPH may help mitigate this risk. Early ADHD detection is vital for nonpharmacological interventions. Orthopedic surgeons should proactively identify ADHD, while healthcare professionals should offer injury prevention guidance, particularly for at-risk groups.

Influence of psychostimulants on bone mineral density and content among children with attention deficit hyperactivity disorder. A systematic review

There is a controversy over the influence of psychostimulant medications on bone mineral density (BMD) and bone mineral content (BMC) among children with attention-deficit-hyperactivity-disorder (ADHD). The aim of the present systematic review was to assess the influence of psychostimulant medications on BMD and BMC among children with ADHD. A comprehensive search of electronic databases, including PubMed, Scopus, Embase, and Cochrane Library, was conducted to identify relevant studies published up until July 2023. Clinical studies that addressed the focused question "Do psychostimulant medications affect bone mineral density and content in children with ADHD?" were included. Letters to the Editor, studies on animal-models, ex-vivo and in-vitro studies, commentaries and reviews were excluded. The primary outcome measures were changes in BMD and BMC. Study quality was assessed using the risk of bias for non-randomized studies-exposure tool. Five non-randomized clinical studies were included. The number of participants ranged from 18 to 6489 with mean ages ranging from 7.3 to 13.75 years. The study durations ranged between five and seven years. In all studies osseous evaluation was done using dual-energy X-ray absorptiometry. The bone locations examined included total body, lumbar-spine, femur, femoral-neck, femoral body, and pelvis. Two studies reported that psychostimulant medications reduce BMC and BMD. In one study, bone turnover, serum leptin and fat levels were reduced in children using psychostimulant medications but no unusual reduction recorded among controls. In general, 80 % of the studies concluded that psychostimulant medications compromise BMC and BMD. Power analysis was done in one study. One study had a low RoB and the remaining demonstrated some concerns. Given the methodological concerns observed in the included studies, arriving at a definitive conclusion regarding the effects of psychostimulant medications on BMC, BMD, and bone turnover in children with ADHD is challenging. However, it is important to acknowledge that an association between psychostimulant medications and these bone-related parameters cannot be disregarded.

Increased fracture risk among children diagnosed with attention- deficit/hyperactivity disorder: a large matched cohort study

To analyse the risk of fractures among children with attention-deficit/hyperactivity disorder (ADHD) compared with matched children without ADHD; and to evaluate the impact of pharmacological treatment. This registry-based cohort study included 31,330 children diagnosed with ADHD and a comparison group of 62,660 children matched by age, sex, population sector and socioeconomic status. Demographic and clinical information was extracted from the electronic database of Meuhedet, a health maintenance organization. Fracture events between 2-18 years of age were identified by coded diagnoses. The overall fracture incidence rate was 334 per 10,000 patient-years (PY) in the ADHD group and 284 per 10,000 PY in the comparison group (p < 0.001). Among boys, the fracture incidence rates were 388 per 10,000 PY and 327 per 10,000 PY (p < 0.001), for the respective groups. Among girls, the rates were lower in both groups compared to boys, but higher in the ADHD compared to the matched group (246 vs 203 per 10,000 PY, p < 0.001). Among the children with ADHD, the hazard ratios (HR) to have a fracture were similar in boys (1.18, 95%CI 1.15-1.22, p < 0.001) and girls (1.22, 95%CI 1.16-1.28, p < 0.001). Children with ADHD were also at increased risk for two and three fractures; the hazard ratios (HRs) were 1.32 (95%CI 1.26-1.38, p < 0.001) and 1.35 (95%CI 1.24-1.46, p < 0.001), respectively. In a multivariable model of the children with ADHD, pharmacological treatment was associated with reduced fracture risk (HR 0.90, 95%CI 0.82-0.98, p < 0.001) after adjustment for sex, resident socioeconomic status and population sector.   Conclusion: Children with ADHD had greater fracture risk than a matched group without ADHD. Pharmacological treatment for ADHD may decrease this risk. What is Known: • Children with attention-deficit/hyperactivity disorder (ADHD) may be more prone to injuries and fractures than children without ADHD. What is New: • Children with ADHD were 1.2 times more likely to have a fracture than children with similar characteristics, without ADHD. The increased risk for fractures was even greater for two and three fractures (hazard ratios 1.32 and 1.35, respectively). • Our study suggests a positive effect of pharmacological treatment for ADHD in reducing fracture risk.

Attention-deficit hyperactivity disorder is associated with relatively short stature among adolescents

AIM

To estimate the association between attention-deficit hyperactivity disorder (ADHD) and relatively short stature (RSS) among adolescents.

METHODS

Participants in the Israeli Youth Health and Nutrition Survey (2015-2016), a cross-sectional school-based study, completed self-administered questionnaires and underwent anthropometric measurements. Height z-score < -0.7 (<25th percentile) was defined as RSS. Multivariable logistic regression analyses assessed the relation between ADHD and RSS, controlling for age, sex, body mass index (BMI) and socioeconomic status (Basic Model), and also for lifestyle factors such as physical activity, sleep duration, dietary patterns and intakes.

RESULTS

Of 4173 participants (11-18 years, 50.2% males), 654 self-reported ever being diagnosed with ADHD; 3519 participants were controls. Overweight (BMI z-score ≥1) and pubertal status were not different among groups. According to the Basic Model, ADHD was significantly associated with RSS (OR 1.25, 95% CI 1.03-1.50), and even after adjustments for lifestyle factors and dietary intake (OR 1.28, 95% CI 1.03-1.58). Stimulant-treated ADHD adolescents had similar height z-scores and lifestyles as those not treated with stimulants.

CONCLUSION

Attention-deficit hyperactivity disorder was associated with RSS. Height deficit may be intrinsic to ADHD or its pharmacotherapy, rather than a consequence of lifestyle alone. Further studies are needed to determine the causal relationship between ADHD and short stature.

Bone health in avoidant/restrictive food intake disorder: a narrative review

BACKGROUND

Avoidant/restrictive food intake disorder (ARFID) is an eating/feeding disturbance characterized by severe food avoidance or restriction that results in faltering growth, nutritional deficiencies, dependence on formula supplementation, and/or significant psychosocial impairment. Compared to other eating disorders, ARFID is observed to have an earlier childhood onset and chronic course without intervention. Childhood represents a sensitive period for longitudinal growth and bone accrual, setting the stage for long-term health outcomes associated with longevity and quality of life, including risk for fracture and osteoporosis.

RESULTS

This narrative review discusses published scientific literature on bone health in individuals with ARFID by describing the current understanding of ARFID's effect on bone health, how common dietary constraints characteristic of ARFID may present unique risks to bone health, and the current clinical recommendations for bone health assessment. Reviewing what is known of clinical data from anorexia nervosa (AN) and similar cohorts, the chronicity and etiology of dietary restriction observed in ARFID are hypothesized to compromise bone health significantly. Although limited, examination of bone health in ARFID patients suggests children with ARFID tend to have shorter stature compared to healthy reference datasets and have lower bone density compared to healthy individuals, similar to those with AN. There remains a substantial knowledge gap in how ARFID may interrupt bone accrual during childhood and adolescence, and subsequent impact on attainment of peak bone mass and peak bone strength. The longitudinal effects of ARFID may be subtle and overlooked clinically in the absence of severe weight loss or growth stunting. Early identification and remediation of threats to bone mass accrual have significant personal and population-level implications.

CONCLUSION

For patients with ARFID, delayed identification and intervention to address feeding disturbances may have a long-lasting impact on various body systems and processes, including those relating to longitudinal growth and bone mass accrual. Further research employing rigorous prospective observational and/or randomized study designs are required to clearly define effects of ARFID, as well as clinical interventions aimed at addressing ARFID-related feeding disturbances, on bone accrual.

Combined methylphenidate and fluoxetine treatment in adolescent rats significantly impairs weight gain with minimal effects on skeletal development

Methylphenidate (MP) is frequently prescribed to treat Attention-Deficit/Hyperactivity Disorder (ADHD); however, many patients with ADHD experience depression and anxiety. As such, concomitant administration of selective serotonin reuptake inhibitors such as fluoxetine (FLX) is common. Our laboratory and others have shown that MP impairs skeletal development in preclinical and clinical settings, and FLX has also been linked to skeletal deficits. Unfortunately, little is known about the effects of combined MP and FLX treatment on skeletal development. The objective of this study was to investigate the effects of MP and FLX on bone morphology and biomechanical properties in adolescent rats. Four-week-old male Sprague-Dawley rats were randomly divided into the following 4 groups: Water, MP, FLX, and MP + FLX. As body weights in the MP, FLX, and MP + FLX groups were all lower than Water, the data were compared directly and after adjusting to body weight via linear regression. The direct comparison revealed that MP + FLX rats had significantly shorter (~12 %) and narrower femora and tibiae (~10 %) compared to most other groups, along with shorter (26-35 %), disorganized tibial growth plates. MicroCT analyses of the trabecular compartment of the proximal tibia identified reductions of 47 % for TV, 86 % for BV, 74 % for BV/TV, 68 % for Tb.N, 25 % in Tb.Th, and 74 % in vBMD concomitant with increases of 44 % for Tb.Sp for MP + FLX compared to Water. Similar analyses of femoral midshaft cortical bone identified reductions of 29 % for Ct.V, 30 % for Ps.V, 30 % for Ec. V, and 51 % for pMOI, as well as increases of 17 % for Ct.Th and 2 % for TMD for MP + FLX compared to Water. Biomechanically, MP + FLX femora were weaker, as indicated by a reduction in ultimate force (14 %) in MP + FLX compared to Water. The microstructural and biomechanical effects of MP + FLX were eliminated after adjustment for body weight, though the detrimental effects on growth plate morphology remained. We conclude that while the adverse microstructural and biomechanical effects of MP + FLX seen via direct comparison are predominantly attributable to reductions in body weight rather than direct effects on bone, MP and FLX, particularly in combination show detrimental effects on growth plate structure and chondrocyte morphology. These findings warrant further research into the effect of these drugs on weight gain, skeletal development and growth plate morphology, as well as consideration by physicians treating children and adolescents with ADHD.

Chondral/Desmal Osteogenesis in 3D Spheroids Sensitized by Psychostimulants

Attention deficit hyperactivity disorder (ADHD) affects 6.4 million children in the United States of America. Children and adolescents, the main consumers of ADHD medication, are in the bone growth phase, which extends over a period of up to two decades. Thus, impaired proliferation and maturation of chondrocytes and osteoblasts can result in impaired bone formation. The aim of this study is to investigate, for the first time, the effects of the ADHD-medication modafinil, atomoxetine and guanfacine on bone growth and repair in vitro. Using two-dimensional and three-dimensional cell models, we investigated the chondrogenic/osteogenic differentiation, proliferation and viability of human mesenchymal progenitor cells. Real-time cell proliferation was measured by xCELLigence. Live/dead staining and size measurement of hMSC- and MG63 monolayer and spheroids were performed after administration of therapeutic plasma concentrations of modafinil, atomoxetine and guanfacine. Chondrogenic differentiation was quantified by RTqPCR. The chondrogenic and osteogenic differentiation was evaluated by histological cryo-sections. Modafinil, atomoxetine and guanfacine reduced chondrogenic and osteogenic differentiation terms of transcript expression and at the histological level. Cell viability of the MG63- and hMSC monolayer was not impeded by ADHD-medication. Our in vitro results indicate that modafinil, atomoxetine and guanfacine may impair chondrogenic and osteogenic differentiation in a 3D model reflecting the in vivo physiologic condition.

Possible Association between Methylphenidate and Mandibular Bone Characteristics Detected by Dental Panoramic Radiograph in Children and Adolescents with ADHD

Some studies have shown that children treated with psychostimulants for attention-deficit hyperactivity disorder (ADHD) have decreased bone mineral density (BMD). Mandibular cortical width (MCW) may be used as a surrogate measure for evaluating BMD. We compared the MCW measured on digital panoramic radiographs (DPR) of 38 children and adolescents with ADHD who were treated with methylphenidate for at least 12 months to the MCW of 58 children and adolescents without ADHD (control). The two groups had a similar mean age (p = 0.3). Mean MCW was significantly lower among children with ADHD compared to those in the control group (2.77 ± 0.33 mm vs. 3.04 ± 0.46 mm, p = 0.004). Additionally, each of the MCW sides were significantly smaller in the group with ADHD compared with the control group. In conclusion, treatment with methylphenidate is associated with low MCW in children and adolescents with ADHD. Analysis of MCW on DPR may help in screening children that are at risk of bone health alterations that may result in low BMD in adulthood. Dentists may be the first to identify bone health abnormalities and should be aware of their role in referring their patients to further follow-up.

Stimulant use and bone health in US children and adolescents: analysis of the NHANES data

Stimulants have become the most popular psychopharmacologic drugs used in therapy for attention-deficit/hyperactivity disorder (ADHD). Childhood and adolescence are crucial periods for optimizing bone health to prevent osteoporosis-related fractures in old age. However, controversy remains regarding the relationship between stimulant use and bone health. The present study was designed to examine the bone mineral content (BMC) and bone mineral density (BMD) of 5472 individuals aged 8-16 years with or without stimulant use based on National Health and Nutrition Examination Survey (NHANES) 2011-2018 data and to further assess the association between stimulant use and bone health. Among these, 284 (5.2%) participants were using stimulants. In analyses stratified by sex, the BMC and BMD at the level of the lumbar spine, pelvis, and total body were generally lower among stimulant users than among nonusers in males (all P < 0.001), while the differences were not statistically significant in females. In multivariable linear regression models, the increasing range of BMCs and BMDs with age was lower in participants using stimulants than in those not using stimulants after fully adjusting for potential confounding factors. Compared to participants not using stimulants, stimulant use ≥ 3 months was associated with significantly lower BMCs [lumbar spine: β =  - 1.35, (95% CI: - 2.56, - 0.14); pelvis: β =  - 9.06, (95% CI: - 15.21, - 2.91); and total: β =  - 52.96, (95% CI: - 85.87, - 20.04)] and BMDs [pelvis: β =  - 0.03, (95% CI: - 0.04, - 0.01), total: β =  - 0.01, (95% CI: - 0.02, - 0.00)].

CONCLUSIONS

Children and adolescents using stimulants exhibited reductions in BMC and BMD at the lumbar spine, pelvis, and total body compared to those who were not using stimulants, especially among males.

WHAT IS KNOWN

• Childhood and adolescence are crucial periods for optimizing bone health to prevent osteoporosis-related fractures in old age. • Controversy remains regarding the relationship between stimulant use and bone health.

WHAT IS NEW

• The bone mineral content and bone mineral density at the level of the lumbar spine, pelvis, and total body were generally lower among stimulant users than among nonusers in males, while the differences were not statistically significant in females. • Body mass index and serum alkaline phosphatase may be predictors for loss of bone mineral content and bone mineral density in stimulant users.

Effect of methylphenidate at different doses on new bone formation with rapid maxillary expansion: A micro-CT and histomorphometric study in rats

OBJECTIVES

This study aimed to evaluate the effect of systemically administered methylphenidate hydrochloride (MPH) on new bone formation in premaxillary suture after rapid maxillary expansion (RME).

SETTING AND SAMPLE POPULATION

Thirty-three Wistar rats were divided into four groups: Group 1 (high dose, 30/60 mg/kg MPH), Group 2 (low dose, 4/10 mg/kg MPH), Group 3 (positive control) and Group 4 (negative control).

METHODS

RME was applied on the 70th day of the study. A 5-day RME period was followed by a 12-day retention period. The experiment was terminated on the 87th day. Micro-CT for radiological evaluation, haematoxylin-eosin and Masson's trichrome staining methods were used for histomorphometric evaluation.

RESULTS

Among experimental groups with RME, the lowest number of osteoblasts and capillaries in Group 1 (P < .05). New bone formation, fibrous callus formation, distal osteotomy line, proximal osteotomy union and cortex remodelling were observed to be lower in Group 1 and Group 2 than Group 3 (P < .05). There was a statistically significant difference between Group 4 and each of the other groups (P = .000) in the evaluation of the results for bone mineral density, bone volume, bone volume percentage, trabecular thickness and trabecular number.

CONCLUSIONS

MPH reduces cellular activity for new bone formation in suture in RME groups. Before performing rapid maxillary expansion in patients using MPH, the use of the drug should be postponed after a multidisciplinary decision process or clinical doses should be lowered.

Long term methylphenidate exposure and growth in children and adolescents with ADHD. A systematic review and meta-analysis

BACKGROUND

Methylphenidate (MPH) is an efficacious treatment for ADHD but concerns have been raised about potential adverse effects of extended treatment on growth.

OBJECTIVES

To systematically review the literature, up to December 2018, conducting a meta-analysis of association of long-term (> six months) MPH exposure with height, weight and timing of puberty.

RESULTS

Eighteen studies (ADHD n = 4868) were included in the meta-analysis. MPH was associated with consistent statistically significant pre-post difference for both height (SMD = 0.27, 95% CI 0.16-0.38, p < 0.0001) and weight (SMD = 0.33, 95% CI 0.22-0.44, p < 0.0001) Z scores, with prominent impact on weight during the first 12 months and on height within the first 24-30 months. No significant effects of dose, formulation, age and drug-naïve condition as clinical moderators were found. Data on timing of puberty are currently limited.

CONCLUSIONS

Long-term treatment with MPH can result in reduction in height and weight. However, effect sizes are small with possible minimal clinical impact. Long-term prospective studies may help to clarify the underlying biological drivers and specific mediators and moderators.

Attention Deficit Hyperactivity Disorder in Athletes

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that manifests in difficulties with sustaining attention in tasks and/or hyperactivity/impulsivity. Prevalence rates vary and difficulties in objectively diagnosing ADHD may lead to overdiagnosis or underdiagnosis. Assessment should include a comprehensive evaluation, including history, physical, psychological evaluation, and questionnaires for ADHD. Stimulant medications are effective for treatment, but their use, side effects, and potential for misuse and abuse are a concern, particularly in athletes. Athletes and physicians also need to be aware of the governing body's drug policy for the sport.

The Impact of Psychotropic Medications on Bone Health in Youth

PURPOSE OF REVIEW

Psychotropics are prescribed to youth at rapidly growing rates and may negatively impact bone health. Little awareness exists of this association among prescribing providers. Childhood and adolescence are critical times for bone development. Understanding these effects and their management is important to informed psychotropic use.

RECENT FINDINGS

Through a variety of mechanisms, antidepressants, benzodiazepines, mood stabilizers, neuroleptics, and stimulants may all negatively impact pediatric bone health. This confers added risk of osteoporosis in a population already at high risk for suboptimal bone health. Awareness of psychotropic-mediated effects on pediatric bone development is clinically relevant to the use and monitoring of these agents. Clinicians can manage these effects through informed consent, vitamin D supplementation, lifestyle modifications, and reducing polypharmacy. For mood stabilizers, vitamin D level monitoring and secondary prevention is indicated. Future longitudinal studies and development of monitoring guidelines regarding psychotropic impact on bone health are necessary.

Past Methylphenidate Exposure and Stress Fractures in Combat Soldiers: A Case-Control Study

BACKGROUND

Previous research has revealed decreased bone mineral density (BMD) among children and adolescents who receive methylphenidate (MP) treatment for attention deficit hyperactivity disorder (ADHD). These findings have major clinical implications given that the prevalence of medication-treated ADHD is on the rise worldwide. We decided to investigate the clinical effect of MP exposure on the incidence of stress fractures, for which a low BMD is a risk factor.

HYPOTHESIS

Exposure to MP is a risk factor for stress fractures.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

This is a case-control study of combat soldiers who served in the military for 3 years between 2005 and 2015. The case group included 2400 soldiers with at least 1 stress fracture diagnosed by a bone scan. The control group comprised 6187 combat soldiers without a diagnosis of a stress fracture. The use of MP was determined by an automated text search of medical records and manual sorting of the results. Other study variables included age; sex; weight; height; body mass index (BMI); place of birth; and characterization of fractures by location, side, and grade. Odds ratios of stress fractures, the attributable proportion among the exposed, and the population attributable fraction were calculated using standard contingency tables. Logistic regression was fitted after adjusting for covariates.

RESULTS

The previous use of MP was associated with a higher risk of stress fractures (odds ratio, 1.15 [95% CI, 1.07-1.24]). The attributable proportion was 13.2%, and the population attributable fraction was 0.3%. Logistic regression demonstrated an increased risk of stress fractures associated with past MP use, preserved after adjusting for BMI, sex, and place of birth ( P = .005). Female sex, BMI ≤20 kg/m², and 20 < BMI ≤25 kg/m² were independent positive predictors of a stress fracture, while African origin was a negative predictor. Most participants who used MP had only 1 fracture (77.8%), while the majority of participants who did not use MP in the past had ≥2 coincident fractures (53.5%) ( P = .003).

CONCLUSION

This study supports the hypothesis that an MP-associated reduction in BMD has a clinical effect in the form of an increased incidence of stress fractures. The high percentage of fractures attributed to MP use may serve as a basis for risk stratification, that is, the referral of patients with a history of MP use to BMD measurements.

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

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is a debilitating mental health problem hampering the child's development. The underlying causes include both genetic and environmental factors and may differ between individuals. The efficacy of diet treatments in ADHD was recently evaluated in three reviews, reporting divergent and confusing conclusions based on heterogeneous studies and subjects. To address this inconsistency we conducted a systematic review of meta-analyses of double-blind placebo-controlled trials evaluating the effect of diet interventions (elimination and supplementation) on ADHD.

METHODS

Our literature search resulted in 14 meta-analyses, six of which confined to double-blind placebo-controlled trials applying homogeneous diet interventions, i.e. artificial food color (AFC) elimination, a few-foods diet (FFD) and poly-unsaturated fatty acid (PUFA) supplementation. Effect sizes (ES) and Confidence intervals (CI) of study outcomes were depicted in a forest plot. I2 was calculated to assess heterogeneity if necessary and additional random effects subgroup meta-regression was conducted if substantial heterogeneity was present.

RESULTS

The AFC ESs were 0.44 (95% CI: 0.16-0.72, I2 = 11%) and 0.21 (95% CI: -0.02-0.43, I2 = 68%) [parent ratings], 0.08 (95% CI: -0.07-0.24, I2 = 0%) [teacher ratings] and 0.11 (95% CI: -0.13-0.34, I2 = 12%) [observer ratings]. The FFD ESs were 0.80 (95% CI: 0.41-1.19, I2 = 61%) [parent ratings] and 0.51 (95% CI: -0.02-1.04, I2 = 72%) [other ratings], while the PUFA ESs were 0.17 (95% CI: -0.03-0.38, I2 = 38%) [parent ratings], -0.05 (95% CI: -0.27-0.18, I2 = 0%) [teacher ratings] and 0.16 (95% CI: 0.01-0.31, I2 = 0%) [parent and teacher ratings]. Three meta-analyses (two FFD and one AFC) resulted in high I2 without presenting subgroup results. The FFD meta-analyses provided sufficient data to perform subgroup analyses on intervention type, resulting in a decrease of heterogeneity to 0% (diet design) and 37.8% (challenge design).

CONCLUSION

Considering the small average ESs PUFA supplementation is unlikely to provide a tangible contribution to ADHD treatment, while further research is required for AFC elimination before advising this intervention as ADHD treatment. The average FFD ES is substantial, offering treatment opportunities in subgroups of children with ADHD not responding to or too young for medication. Further FFD research should focus on establishing the underlying mechanisms of food (e.g. incrimination of gut microbiota) to simplify the FFD approach in children with ADHD.