February 13, 2022

Nationwide cohort study finds association between miscarriage and ADHD

Spontaneous abortion is the medical term used for what is more commonly known as miscarriage. It means the unintended loss of an embryo or fetus before the 20th week of pregnancy. This must not be confused in any way with induced abortion, which is a deliberate and intentional act to terminate a pregnancy.

Most miscarriages occur when the fetus is not developing properly. Among the major causes of miscarriage are chromosomal abnormalities, birth defects, abnormal hormonal imbalances, infections, and exposure to toxins.

A team of Chinese researchers used the Danish national registers to explore a nationwide cohort for associations between previous miscarriage and ADHD in subsequent offspring. They included all 1.1 million births in Denmark over the 17 years from 1995 through 2012. They excluded all children with chromosomal abnormalities, those born either extremely early (after less than 22 weeks gestation) or extremely late (greater than 45 weeks), and those for whom this information was missing. That left over one million children in the study cohort.

The team classified children as having ADHD either based on a recorded hospital diagnosis or after receiving ADHD medication prescriptions at least twice after the age of 3 years. A total of 25,747 children were identified as ADHD individuals (554 mothers having at least two miscarriages, 3,087 mothers having one miscarriage, and 22,106 mothers without miscarriage). The average age of the first ADHD diagnosis was 10 years.

Just over 130,000 children (12.2%) were born to mothers who had at least one miscarriage. Of these, just under 113,000 (10.6%) were born to mothers with a single miscarriage before birth, and just over 17,000 to mothers with more than one prior miscarriage.

Based on previous research, the team identified potential confounders, including sex, preterm birth (less than 37 weeks), low birth weight, small for gestational age, low Agar score (performed right after birth to assess the risk of infant mortality), maternal and paternal ages at birth, maternal diabetes, maternal hypothyroidism, maternal smoking during pregnancy, maternal education level, maternal and paternal psychiatric disorders before birth.

After adjusting for these possible confounders, children of mothers with a single prior miscarriage were 9% more likely to develop ADHD than those of mothers without any miscarriage. Children of mothers with two or more prior miscarriages were 22% more likely to be diagnosed with ADHD. This upward exposure-response trend was statistically significant.

Preterm birth was found to be the strongest confounding mediator of this trend but accounted for under 4% of the association. The authors concluded, "the observed associations were independent of several factors, such as maternal socioeconomic status, type of spontaneous abortion, parental history of psychiatric disorders, pregnancy characteristics (maternal smoking status, infection, diabetes and hypothyroidism status during pregnancy)and birth outcomes (low birth weight, preterm birth, low Agar score, and small for gestational age)."

They also noted that given the frequency of miscarriages, affecting more than one in eight women, "a small increase of neurodevelopmental problems in offspring could have major public health implications."

Hui Wang, Fei Li, Maohua Miao, Yongfu Yu, Honglei Ji, HuiLiu, Rong Huang, Carsten Obel, Jun Zhang, and Jiong Li, "Maternal spontaneous abortion and the risk of attention-deficit/ hyperactivity disorder in offspring: a population-based cohort study", Human Reproduction(2020), vol. 35, no. 5, 1211-1221,https://doi.org/10.1093/humrep/deaa035.

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News Tuesday: Fidgeting and ADHD

A recent study delved into the connection between fidgeting and cognitive performance in adults with Attention-Deficit/Hyperactivity Disorder. Recognizing that hyperactivity often manifests as fidgeting, the researchers sought to understand its role in attention and performance during cognitively demanding tasks. They designed a framework to quantify meaningful fidgeting variables using actigraphy devices.

(Note: Actigraphy is a non-invasive method of monitoring human rest/activity cycles. It involves the use of a small, wearable device called an actigraph or actimetry sensor, typically worn on the wrist, similar to a watch. The actigraph records movement data over extended periods, often days to weeks, to track sleep patterns, activity levels, and circadian rhythms. In this study, actigraphy devices were used to measure fidgeting by recording the participants' movements continuously during the cognitive task. This data provided objective, quantitative measures of fidgeting, allowing the researchers to analyze its relationship with attention and task performance.)

The study involved 70 adult participants aged 18-50, all diagnosed with ADHD. Participants underwent a thorough screening process, including clinical interviews and ADHD symptom ratings. The analysis revealed that fidgeting increased during correct trials, particularly in participants with consistent reaction times, suggesting that fidgeting helps sustain attention. Interestingly, fidgeting patterns varied between early and later trials, further highlighting its role in maintaining focus over time.

Additionally, a correlation analysis validated the relevance of the newly defined fidget variables with ADHD symptom severity. This finding suggests that fidgeting may act as a compensatory mechanism for individuals with ADHD, aiding in their ability to maintain attention during tasks requiring cognitive control.

This study provides valuable insights into the role of fidgeting in adults with ADHD, suggesting that it may help sustain attention during challenging cognitive tasks. By introducing and validating new fidget variables, the researchers hope to standardize future quantitative research in this area. Understanding the compensatory role of fidgeting can lead to better management strategies for ADHD, emphasizing the potential benefits of movement for maintaining focus.

July 16, 2024

Identifying Autistic-Like Symptoms in Children with ADHD

NEWS TUESDAY: Identifying Autistic-Like Symptoms in Children with ADHD

A recent study investigated the presence of autistic-like symptoms in children diagnosed with Attention Deficit/Hyperactivity Disorder (ADHD). Given the overlapping social difficulties in both ADHD and Autism Spectrum Disorder (ASD), distinguishing between the two disorders can be challenging. This study aims to pinpoint specific patterns of autistic symptoms in children with ADHD, comparing them to those with ASD using the Autism Diagnostic Observation Schedule, 2nd edition (ADOS-2).

The research involved 43 school-age children divided into two groups:

  • ADHD Group (25 children): Initially referred for ASD symptoms but later diagnosed with ADHD.
  • ASD Group (18 children): Children diagnosed with ASD.

Researchers used ADOS-2 to evaluate differences in communication deficits, social interaction challenges, and repetitive behaviors between the two groups. The study also compared IQ, age, ADOS-2 domain scores, and externalizing/internalizing problems.

Key Findings:

  • Significant differences were found between the ADHD and ASD groups in ADOS-2 domain scores, including Social Affect, Restricted and Repetitive Behavior, and Total Score.
  • On an individual item level, children with ADHD displayed similar atypical behaviors as those with ASD in social-communication areas such as "Pointing" and "Gestures".
  • Both groups showed comparable frequencies in behaviors like "Stereotyped/idiosyncratic words or phrases", "Mannerisms", and "Repetitive interests and behaviors".

The study highlights the importance of identifying transdiagnostic domains that overlap between ADHD and ASD. The transdiagnostic domain refers to a set of symptoms or behaviors that are common across multiple diagnostic categories rather than being specific to just one. Identifying these domains in mental health practice and in psychological research is crucial to understanding, properly diagnosing, and treating conditions with overlapping features. This understanding could pave the way for tailored treatments addressing the specific needs of children with ADHD, particularly those exhibiting autistic-like symptoms.

July 9, 2024

Non-stimulant Medications for Adults with ADHD: An Overview

NEW STUDY: Non-stimulant Medications for Adults with ADHD: An Overview

Attention-Deficit/Hyperactivity Disorder (ADHD) in adults is commonly treated with stimulant medications such as methylphenidate and amphetamines. However, not all patients respond well to these stimulants or tolerate them effectively. For such cases, non-stimulant medications provide an alternative treatment approach.

Recent research by Brancati et al. reviews the efficacy and safety of non-stimulant medications for adult ADHD. Atomoxetine, a well-studied non-stimulant, has shown significant effectiveness in treating ADHD symptoms in adults. The review highlights the importance of considering dosage, treatment duration, safety, and the presence of psychiatric comorbidities when prescribing atomoxetine.

Additionally, certain antidepressants, including tricyclic compounds, bupropion, and viloxazine, which possess noradrenergic or dopaminergic properties, have demonstrated efficacy in managing adult ADHD. Antihypertensive medications, especially guanfacine, have also been found effective. Other medications like memantine, metadoxine, and mood stabilizers show promise, whereas treatments like galantamine, antipsychotics, and cannabinoids have not yielded positive results.

The expert opinion section of the review emphasizes that while clinical guidelines primarily recommend atomoxetine as a second-line treatment, several other non-stimulant options can be utilized to tailor treatments based on individual patient needs and comorbid conditions. Despite these advancements, the authors call for further research to develop and refine more personalized treatment strategies for adults with ADHD.

This review underscores the growing landscape of non-stimulant treatment options, offering hope for more personalized and effective management of ADHD in adults.

June 25, 2024