ADHD misdiagnosis: Causes and mitigators

Systematic review and meta-analysis: relative age in attention-deficit/ hyperactivity disorder and autism spectrum disorder

Youngest students in their class, with birthdates just before the school entry cut-off date, are overrepresented among children receiving an Attention-Deficit/Hyperactivity Disorder (ADHD) diagnosis or medication for this. This is known as the relative age effect. This systematic review and meta-analysis summarises the evidence on the influence of relative age on ADHD symptoms, diagnosis and medication prescribing. As no review to date has investigated the association with autism spectrum disorder (ASD) diagnosis, this is also examined. Following prospective registration with PROSPERO, we conducted a systematic review according to the PRISMA guidelines. We searched seven databases: Medline, Embase, PsycInfo, Web of Science Core Collection, ERIC, Psychology and Behavioural Sciences Collection, and Cochrane Library. Additional references were identified from manual search of retrieved reviews. We performed a meta-analysis of quantitative data. Thirty-two studies were included, thirty-one investigated ADHD and two ASD. Younger relative age was associated with ADHD diagnosis and medication, with relative risks of 1.38 (1.36-1.52 95% CI) and 1.28 (1.21-1.36 95% CI) respectively. However, risk estimates exhibited high heterogeneity. A relative age effect was observed for teacher ratings of ADHD symptoms but not for parent ratings. With regard to ASD, the youngest children in their school year were more likely to be diagnosed with ASD. This review confirms a relative age effect for ADHD diagnosis and prescribed ADHD medication and suggests that differences in teacher and parent ratings might contribute to this. Further research is needed on the possible association with ASD.

Sex differences in psychiatric comorbidities of attention-deficit/hyperactivity disorder among children, adolescents, and adults: A nationwide population-based cohort study

This cross-sectional, nationwide, population-based study aimed to elucidate sex differences in psychiatric comorbidities of Attention-deficit/hyperactivity disorder (ADHD) across children, adolescents, and adults. We analyzed data from Taiwan's comprehensive healthcare database, including 112,225 individuals diagnosed with ADHD, categorized by age (0-12, 13-18, ≥18 years) and sex. Psychiatric comorbidities were assessed using ICD-9-CM codes, focusing on age and sex-specific prevalence. Among the cohort, 83.50% were children (0-12 years) presenting primarily with learning disabilities and tics, while adolescents (13-18 years; 11.88%) had higher instances of oppositional defiant and conduct disorders. In adults (≥18 years; 4.62%), the prevalence of anxiety, depression, bipolar disorder, and substance misuse was notably higher. Males under 18 predominantly had ADHD, whereas females exhibited increased vulnerability to emotional disorders. In adulthood, males showed greater susceptibility to most psychiatric comorbidities, except sleep disorders. The study highlights the evolving nature of ADHD-related psychiatric comorbidities across different life stages, with distinct sex-based patterns. The transition from childhood to adulthood sees an increased prevalence of various psychiatric conditions, particularly impacting adult males. These findings underscore the need for age- and sex-specific therapeutic approaches in ADHD management. The cultural context of the study necessitates further research in diverse populations for broader applicability of the findings.

The associations between levels of inattention/hyperactivity and social media addiction among young adults: The mediating role of emotional regulation strategies in self-blame and blaming others

Attention-deficit/hyperactivity disorder (ADHD) is a common neurobehavioral disorder beginning in childhood and often extending into adulthood. ADHD may negatively impact emotional regulation and cause addictive behaviors such as social media addiction. The present study investigated the association of ADHD symptoms (i.e., attention deficit [AD] and hyperactivity/impulsivity [HI]) with social media addiction among young adults. The mediating effect of internalizing and externalizing emotional regulation (i.e., self-blame [SB] and blaming others [BO]) were examined. Participants (n = 96; mean age = 19.9 years [SD = 2.07]) comprising 35 individuals with probable ADHD and 61 individuals who did not have ADHD completed measures assessing social media addiction, ADHD symptoms, and emotional regulation strategies. Results of Hayes' Process Micro showed that both ADHD symptoms were significantly positively associated with social media addiction (standardized coefficient [β] = 0.30 and 0.38 for AD and HI) and emotional regulation strategies (β = 0.38 and 0.27 for AD to SB and BO, β = 0.23 and 0.28 for HI to SB and BO). In addition, BO was a significant mediator in the association between AD and social media addiction (β = 0.07, 95 % confidence interval = 0.003, 0.11). The results suggest that externalizing emotional regulation may mediate the association between symptoms of AD and social media addiction. It is recommended that individuals with probable ADHD should focus on improving self-awareness (such as mindfulness), developing resilience skills, and/or incorporating positive coping strategies (such as physical activity) to reduce the negative impacts derived from symptoms of ADHD.

Predicting ADHD in alcohol dependence using polygenic risk scores for ADHD

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder with a high degree of comorbidity, including substance misuse. We aimed to assess whether ADHD polygenic risk scores (PRS) could predict ADHD diagnosis in alcohol dependence (AD). ADHD PRS were generated for 1223 AD subjects with ADHD diagnosis information and 1818 healthy controls. ADHD PRS distributions were compared to evaluate the differences between healthy controls and AD cases with and without ADHD. We found increased ADHD PRS means in the AD cohort with ADHD (mean 0.30, standard deviation (SD) 0.92; p = 3.9 × 10-6); and without ADHD (mean - 0.00, SD 1.00; p = 5.2 × 10-5) compared to the healthy control subjects (mean - 0.17, SD 0.99). The ADHD PRS means differed within the AD group with a higher ADHD PRS mean in those with ADHD, odds ratio (OR) 1.34, confidence interval (CI) 1.10 to 1.65; p = 0.002. This study showed a positive relationship between ADHD PRS and risk of ADHD in individuals with co-occurring AD indicating that ADHD PRS may have utility in identifying individuals that are at a higher or lower risk of ADHD. Further larger studies need to be conducted to confirm the reliability of the results before ADHD PRS can be considered as a robust biomarker for diagnosis.

Optimal timing of influenza vaccination in young children: population based cohort study

OBJECTIVE

To assess optimal timing of influenza vaccination in young children.

DESIGN

Population based cohort study.

SETTING

United States.

PARTICIPANTS

Commercially insured children aged 2-5 years who were vaccinated against influenza during 2011-18.

MAIN OUTCOME MEASURE

Rates of diagnosis of influenza among children who were vaccinated against influenza, by birth month.

RESULTS

Overall, 819 223 children aged 2-5 received influenza vaccination. Children vaccinated in November and December were least likely to have a diagnosis of influenza, a finding that may be confounded by unmeasured factors that influence the timing of vaccination and risk of influenza. Vaccination commonly occurred on days of preventive care visits and during birth months. Children born in October were disproportionately vaccinated in October and were, on average, vaccinated later than children born in August and earlier than those born in December. Children born in October had the lowest rate of influenza diagnosis (for example, 2.7% (6016/224 540) versus 3.0% (6462/212 622) for those born in August; adjusted odds ratio 0.88, 95% confidence interval 0.85 to 0.92).

CONCLUSIONS

In a quasi-experimental analysis of young children vaccinated against influenza, birth month was associated with the timing of vaccination through its influence on the timing of preventive care visits. Children born in October were most likely to be vaccinated in October and least likely to have a diagnosis of influenza, consistent with recommendations promoting October vaccination.

Public drug insurance, moral hazard and children's use of mental health medication: Latent mental health risk-specific responses to lower out-of-pocket treatment costs

Studies have shown that reducing out-of-pocket costs can lead to higher medication initiation rates in childhood. Whether the cost of such initiatives is inflated by moral hazard issues remains a question of concern. This paper looks to the implementation of a public drug insurance program in Québec, Canada, to investigate potential low-benefit consumption in children. Using a nationally representative longitudinal sample, we harness machine learning techniques to predict a child's risk of developing a mental health disorder. Using difference-in-differences analyses, we then assess the impact of the drug program on children's mental health medication uptake across the distribution of predicted mental health risk. Beyond showing that eliminating out-of-pocket costs led to a 3 percentage point increase in mental health drug uptake, we show that demand responses are concentrated in the top two deciles of risk for developing mental health disorders. These higher-risk children increase take-up of mental health drugs by 7-8 percentage points. We find even stronger effects for stimulants (8-11 percentage point increases among the highest risk children). Our results suggest that reductions in out-of-pocket costs could achieve better uptake of mental health medications, without inducing substantial low-benefit care among lower-risk children.