June 19, 2025

Nationwide Population Study Reports Increased Risk of Hospitalization for Psychosis or Mania Following Initiation of ADHD Medication

Background:

In Iceland, treatment with ADHD medication can only be initiated by psychiatrists or pediatricians with experience in diagnosing neurodevelopmental disorders. The diagnostic evaluation is most often carried out by a psychologist or psychiatrist, and must be confirmed by a psychiatrist. 

Some previous studies have suggested a small but significant increased risk of psychosis or mania associated with ADHD medication, while others have not. 

Iceland has a single-payer national healthcare insurance system that tracks virtually its entire population. An Icelandic research team accessed two administrative databases with nationwide coverage – the Icelandic Prescription Medicines Register and the Icelandic Hospital Discharge Register – to explore this relationship among all adults from 2010 through 2022. 

They included three categories of ADHD medications prescribed in Iceland: amphetamines, including dexamphetamine and lisdexamphetamine; methylphenidate; and atomoxetine. In Iceland, methylphenidate or atomoxetine must be prescribed and tried first before switching to lisdexamphetamine or dexamphetamine. 

Method:

Diagnoses of mania or psychosis recorded in electronic health records were used to identify individuals who were admitted to a psychiatric ward within one year of starting treatment with a specific class of ADHD medication. First-onset psychosis or mania was defined as the emergence of these conditions in individuals with no prior history, diagnosis, or hospitalization for psychosis or mania. 

A total of 16,125 adults began using an ADHD medication for the first time during the 13-year study period. 

Methylphenidate was the most used ADHD medication among those admitted for psychosis or mania (25 out of 61; 41%), reflecting its status as the most frequently prescribed stimulant during the study period. It was followed by amphetamines (21 out of 61; 34.4%) and atomoxetine (15 out of 61; 24.6%). 

Half of those hospitalized had previously received a diagnosis of substance use disorder. One in nine (11%) of those hospitalized acknowledged misuse of the type of ADHD medication they had been prescribed. 

Within a year of discharge, 42 out of the 61 patients (68.9%) had been prescribed an ADHD medication again. Among those, one in four (11 out of 42; 26%) were readmitted for psychosis or mania within the following year.  

The team noted, “It is concerning that most patients (68.9%) in our study resumed ADHD drug treatment within a year of hospital discharge … However, some studies have reported that the use of psychostimulants or atomoxetine to treat ADHD in individuals with psychotic disorders did not increase the risk of hospitalisation for psychosis if used concurrently with antipsychotic medication or that such use might even reduce this risk.”  

Findings: 

By comparison with the general population, adults initiating ADHD medications had eight times the relative risk of being admitted for psychosis or mania within the first year.  

The absolute risk was low: 0.38% overall for those initiating ADHD medication.  Adjusting for the general population risk of hospitalization for first-onset psychosis or mania, more than 300 patients would need to be initiated to ADHD medication to generate one hospital admission for psychosis or mania

The team conceded, “Confounders of real-life clinical settings, such as non-disclosed ADHD drug abuse or misuse or some degree of substance abuse, may have influenced our findings.” 

A further, unmentioned, limitation is that the team did not perform any of the usual adjustments for confounding variables, critically including co-occurring (comorbid) psychiatric disorders known to be common with ADHD, and likely to have a major effect on the relative risk of hospitalization. 

Given the very small increase in risk along with the methodological flaws, the team’s suggestion of a “potential causal role of ADHD drugs in the development of first-onset psychosis or mania” is unsubstantiated and speculative.  This is especially so given other studies suggesting no increased risk for psychosis due to these medications.  

In any event, causation cannot be established through observational studies.

Ragna Kristin Gudbrandsdottir, Engilbert Sigurdsson, Þorsteinn Ivar Albertsson, Halldora Jonsdottir, and Oddur Ingimarsson, “Risk of hospitalisation for first-onset psychosis or mania within a year of ADHD medication initiation in adults with ADHD,” BMJ Mental Health (2025), 28: 1–7, https://doi.org/10.1136/bmjment-2024-301521.

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Evidence-Based Interventions for ADHD

EBI-ADHD: 

If you live with ADHD, treat ADHD, or write about ADHD, you’ve probably run into the same problem: there’s a ton of research on treatments, but it’s scattered across hundreds of papers that don’t talk to each other.  The EBI-ADHD website fixes that. 

EBI-ADHD (Evidence-Based Interventions for ADHD) is a free, interactive platform that pulls together the best available research on how ADHD treatments work and how safe they are. It’s built for clinicians, people with ADHD and their families, and guideline developers who need clear, comparable information rather than a pile of PDFs. EBI-ADHD Database  The site is powered by 200+ meta-analyses covering 50,000+ participants and more than 30 different interventions.  These include medications, psychological therapies, brain-stimulation approaches, and lifestyle or “complementary” options. 

The heart of the site is an interactive dashboard.  You can: 

  1. Choose an age group: children (6–17), adolescents (13–17), or adults (18+). 
  1. Choose a time frame: results at 12, 26, or 52 weeks. 
  1. Choose whether to explore by intervention (e.g., methylphenidate, CBT, mindfulness, diet, neurofeedback) or by outcome (e.g., ADHD symptoms, functioning, adverse events), depending on what’s available. EBI-ADHD Database 

The dashboard then shows an evidence matrix: a table where each cell is a specific treatment–outcome–time-point combination. Each cell tells you two things at a glance: 

  1. How big the effect is, compared to placebo or another control (large benefit, small benefit, no effect, small negative impact, large negative impact). 
  1. How confident we can be in that result (high, moderate, low, or very low certainty).  

Clicking a cell opens more detail: effect sizes, the underlying meta-analysis, and how the certainty rating was decided. 

EBI-ADHD is not just a curated list of papers. It’s built on a formal umbrella review of ADHD interventions, published in The BMJ in 2025. That review re-analyzed 221 meta-analyses using a standardized statistical pipeline and rating system. 

The platform was co-created with 100+ clinicians and 100+ people with lived ADHD experience from around 30 countries and follows the broader U-REACH framework for turning complex evidence into accessible digital tools.  

Why it Matters 

ADHD is one of the most studied conditions in mental health, yet decisions in everyday practice are still often driven by habit, marketing, or selective reading of the literature. EBI-ADHD offers something different: a transparent, continuously updated map of what we actually know about ADHD treatments and how sure we are about it. 

In short, it’s a tool to move conversations about ADHD care from “I heard this works” to “Here’s what the best current evidence shows, and let’s decide together what matters most for you.” 

Meta-analysis Finds Tenuous Links Between ADHD and Thyroid Hormone Dysregulation

The Background:

Meta-analyses have previously suggested a link between maternal thyroid dysfunction and neurodevelopmental disorders (NDDs) in children, though some studies report no significant difference. Overweight and obesity are more common in children and adolescents with NDDs. Hypothyroidism is often associated with obesity, which may result from reduced energy expenditure or disrupted hormone signaling affecting growth and appetite. These hormone-related parameters could potentially serve as biomarkers for NDDs; however, research findings on these indicators vary. 

The Study:

A Chinese research group recently released a meta-analysis examining the relationship between neurodevelopmental disorders (NDDs) and hormone levels – including thyroid, growth, and appetite hormones – in children and adolescents.  

The analysis included peer-reviewed studies that compared hormone levels – such as thyroid hormones (FT3, FT4, TT3, TT4, TSH, TPO-Ab, or TG-Ab), growth hormones (IGF-1 or IGFBP-3), and appetite-related hormones (leptin, ghrelin, or adiponectin) – in children and adolescents with NDDs like ADHD, against matched healthy controls. To be included, NDD cases had to be first-diagnosis and medication-free, or have stopped medication before testing. Hormone measurements needed to come from blood, urine, or cerebrospinal fluid samples, and all studies were required to provide both means and standard deviations for these measurements. 

Meta-analysis of nine studies encompassing over 5,700 participants reported a medium effect size increase in free triiodothyronine (FT3) in children and adolescents with ADHD relative to healthy controls. There was no indication of publication bias, but variation between individual study outcomes (heterogeneity) was very high. Further analysis showed FT3 was only significantly elevated in the predominantly inattentive form of ADHD (three studies), again with medium effect size, but not in the hyperactive/impulsive and combined forms

Meta-analysis of two studies combining more than 4,800 participants found a small effect size increase in thyroid peroxidase antibody (TPO-Ab) in children and adolescents with ADHD relative to healthy controls. In this case, the two studies had consistent results. Because only two studies were involved, there was no way to evaluate publication bias. 

The remaining thyroid hormone meta-analyses, involving 6 to 18 studies and over 5,000 participants in each instance, found no significant differences in levels between children and adolescents with ADHD and healthy controls

Meta-analyses of six studies with 317 participants and two studies with 192 participants found no significant differences in growth hormone levels between children and adolescents with ADHD and healthy controls. 

Finally, meta-analyses of nine studies with 333 participants, five studies with 311 participants, and three studies with 143 participants found no significant differences in appetite-related hormone levels between children and adolescents with ADHD and healthy controls. 

The Conclusion:

The team concluded that FT3 and TPO-Ab might be useful biomarkers for predicting ADHD in youth. However, since FT3 was only linked to inattentive ADHD, and TPO-Ab’s evidence came from just two studies with small effects, this conclusion may overstate the meta-analysis results. 

Our Take-Away:

Overall, this meta-analysis found only limited evidence that hormone differences are linked to ADHD. One thyroid hormone (FT3) was higher in children with ADHD—mainly in the inattentive presentation—but the findings varied widely across studies. Another marker, TPO-Ab, showed a small increase, but this came from only two studies, making the result less certain. For all other thyroid, growth, and appetite-related hormones, the researchers found no meaningful differences between children with ADHD and those without. While FT3 and TPO-Ab may be worth exploring in future research, the current evidence is not strong enough to consider them reliable biomarkers.

 

December 15, 2025

Meta-analysis Finds Assisted Reproductive Techniques Associated with Offspring ADHD

Meta-analysis Finds Assisted Reproductive Techniques Associated with Offspring ADHD 

Background:

Recent progress in reproductive medicine has increased the number of children conceived via assisted reproductive techniques (ART). These include: 

  • In vitro fertilization (IVF), in which eggs are retrieved from the ovaries and fertilized with sperm in a laboratory; embryos are then transferred into the uterus.  
  • Intracytoplasmic sperm injection (ICSI), where a single sperm is injected directly into an egg. 
  • Intrauterine insemination (IUI), in which sperm is placed directly into the uterus around the time of ovulation. This is often combined with ovulation-inducing (OI) medications. 

Although ART helps with infertility, there are concerns about its long-term effects on offspring, especially regarding neurodevelopment. Factors such as hormonal treatments, gamete manipulation, altered embryonic environments, as well as parental age and infertility, may influence brain development and raise the risk of neurodevelopmental and mental health disorders. 

With previous studies finding conflicting results on a possible association between ART and increased risk of mental health disorders, an Indian research team has just published a new meta-analysis exploring this topic. 

The Study:

Studies were eligible if they were observational (cohort, case-control, or cross-sectional), reported confounder-adjusted effect sizes for ADHD, and were published in English in peer-reviewed journals. 

A meta-analysis of eight studies encompassing nearly twelve million individuals indicated a 7% higher prevalence of ADHD in offspring conceived via IVF/ICSI compared to those conceived naturally. The heterogeneity among studies was minimal, and no evidence of publication bias was observed. 

The study’s 95% confidence interval ranged from 4% to 10%. Further analysis of five studies comprising almost nine million participants that distinguished outcomes by sex revealed that the increase in ADHD risk among female offspring was not statistically significant. In contrast, the elevated risk in male offspring persisted, though it was marginally significant, with the lower bound of the confidence limit at only 1%. 

Results:

A meta-analysis of three studies (1.4 million participants) found a 13% higher rate of ADHD in children conceived via ovulation induction/intrauterine insemination (OI/IUI) compared to natural conception. The effect size, though doubled, remains small. Minimal heterogeneity and no publication bias were observed. 

The team concluded, “The review found a small but statistically significant moderate certainty evidence of an increased risk of ADHD in those conceived through ART, compared to spontaneous conception. The magnitude of observed risk is small and is reassuring for parents and clinicians.” 

Our Take-Away:

Overall, the meta-analysis points to a small, but measurable increase in ADHD diagnoses among children conceived through ART, but the effect sizes are modest and supported by moderate-certainty evidence. And we must always keep in mind that the researchers who wrote the original articles could not correct for all possible confounds.  These findings suggest that while reproductive technologies may introduce slight variation in neurodevelopmental outcomes, the effects are small and uncertain. For families and clinicians, the results are generally reassuring: ART remains a safe and effective avenue to parenthood, and the results of this study should not be viewed as a prohibitive concern. Thoughtful developmental monitoring and open, evidence-based counseling can help ensure that ART-conceived children receive support that caters to their individual needs.

 

December 12, 2025