August 15, 2024

Meta-analysis Finds Strong Placebo Response in Treatment of ADHD, Mid-range Among Nine Neurological Disorders

A placebo is a pill that does not contain any active medication.  It is given to patients who form the control group in clinical trials.  Comparing the effects of a treatment with placebo is essential because some patients will improve with the passage of time and some will get better due to the expectation of benefit they have from being enrolled in a clinical trial.

In studies of psychiatric conditions, patients in placebo groups typically show improvement. This can be induced by combinations of hope, suggestion, expectation, and consumption of what are presented as medications. It is reinforced by the context of receiving compassionate care from others, with supportive conversations. 

A 2005 study found that placebo response is unequally distributed across psychiatric disorders, but did not address several disorders (including bipolar disorder) examined in the present meta-analysis conducted by a German research team. 

Using only high-quality randomized clinical trials (RCTs) across major psychiatric diagnoses, the team quantified differences in the change of disorder symptoms within placebo groups.  

They selected nine common and clinically significant psychiatric conditions: major depressive disorder (MDD), mania (bipolar disorder), schizophrenia, obsessive-compulsive disorder (OCD), attention-deficit/hyperactivity disorder (ADHD), generalized anxiety disorder (GAD), panic disorder, posttraumatic stress disorder (PTSD), and social phobia. For each of these, they selected the ten most recent high-quality RCTs of medicationsfor meta-analysis. 

Of the ninety included RCTs, the team only looked at placebo groups. Because RCTs for the different diagnoses used differing established psychopathology rating scales, standardized pre-post effect sizes were used to compare outcomes across diagnoses. 

Meta-analysis of the ten ADHD RCTs with a combined total of 1,189 participants reported large effect size improvements in symptoms, with no variation (heterogeneity) across RCTs and no sign of publication bias. 

By contrast, the placebo effect size improvements in symptoms of major depressive disorder (10 RCTs, 1,598 participants) and generalized anxiety disorder (10 RCTs, 1,457 participants) were very large, well above those for ADHD, and with no overlap of 95% confidence intervals. 

At the other end of the spectrum, the placebo effect size improvements in symptoms of schizophrenia (10 RCTs, 888 participants) were moderate, well below those for ADHD, and with no overlap of 95% confidence intervals. 

There were absolutely no indications of publication bias. 

The team noted, “In all diagnoses, there were improvements in symptom severity during placebo treatment (ie, the lower limit of the 95% CIs of the pooled pre-post placebo effect sizes were >0).” Although they stated, “The large and robust improvements observed in ADHD studies have not been reported to our knowledge.”  they seemed to have missed this article by me and my colleagues:  https://pubmed.ncbi.nlm.nih.gov/34232582/

They also concluded, “Comparing the courses of different disorders under placebo indirectly may assist in understanding disease etiology, possibly providing insights into the proportionate influence of organic and psychogenic factors. Conditions with presumed substantial hereditary and biological components, such as schizophrenia, exhibited modest placebo responses in our analysis. Conversely, disorders with potentially less biological contribution, eg, depression and GAD, showed stronger responses. Our study may serve as an initial framework for incorporating the comprehensive insights derived from placebo groups of controlled trials into the etiopathogenetic exploration of mental illnesses.”

Yanli Zhang-James, John W.S. Clay, Rachel B. Aber, Hilary M. Gamble, Stephen V. Faraone,
Post–COVID-19 Mental Health Distress in 13 Million Youth: A Retrospective Cohort Study of Electronic Health Records,
Journal of the American Academy of Child & Adolescen

Tom Bschor, Lea Nagel, Josephine Unger, Guido Schwarzer, and Christopher Baethge, “Differential Outcomes of Placebo Treatment Across 9 Psychiatric Disorders: A Systematic Review and Meta-Analysis,” JAMA Psychiatry (2024), https://doi.org/10.1001/jamapsychiatry.2024.0994

Faraone, S. V., Newcorn, J. H., Cipriani, A., Brandeis, D., Kaiser, A., Hohmann, S., Haege, A. & Cortese, S. (2021). Placebo and nocebo responses in randomised, controlled trials of medications for ADHD: a systematic review and meta-analysis. Mol Psychiatry 27, 212-219.

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What is The Pharmaceutical Supply Chain? Addressing The ADHD Medication Shortage

The persistent shortage of ADHD medications has been more than a simple annoyance for patients at the pharmacy; the inconsistent availability of these medications has had deep impacts on the daily lives of those struggling without them. While public discourse has pointed fingers at over-prescribing or at restrictive DEA quotas, a recent economic evaluation in JAMA Health Forum suggests we’ve been looking in the wrong direction for an answer to what is causing this. 

The reality of the shortage is less about increased demand and more about a fragile, globalized supply chain that snapped at a critical link. 

Debunking the "Quota Myth":

The prevailing narrative suggested that the Drug Enforcement Administration (DEA) was stifling production by refusing to raise quotas. However, the data tells a different story. In 2022, manufacturers collectively met only about 70% of their allotted production quotas. 

So we know that the problem wasn't that this DEA quota ceiling was too low. In fact, most manufacturers couldn't even reach it. Even when accounting for exports and domestic retail, production remained significantly below the legal limit. Even if the DEA had doubled its quotas, these medications still likely wouldn't have magically appeared on pharmacy shelves. 

The most striking finding in the study is the correlation between the shortage and a sharp decline in the import of raw Active Pharmaceutical Ingredients (APIs).  For the past decade, Germany has accounted for over 85% of US amphetamine imports. In 2022, these imports dropped by approximately 36.7%.  When the API doesn't arrive at the factory, production for medium and small manufacturers grinds to a halt. Unlike larger pharmaceutical giants, these smaller players often lack the inventory cushion or flexibility to quickly pivot to a new supplier. 

When the primary supply of amphetamine-based stimulants (like Adderall) faltered, it triggered a secondary crisis. Patients and clinicians, seeking alternatives, shifted toward lisdexamfetamine (Vyvanse) and methylphenidate (Ritalin/Concerta). 

  • Substitution Strain: This sudden migration of millions of patients created a domino effect, eventually leading to shortages in those medications as well. 
  • The Tolerance Gap: As any clinician knows, these stimulants are not perfect substitutes. Switching a stabilized patient to a different class of medication often leads to a trial-and-error period that may be characterized by poor tolerability or reduced efficacy. 

If we view this shortage purely through a regulatory or clinical lens, we miss the underlying cause of the crisis. The pharmaceutical industry has become a victim of its reliance on "just-in-time manufacturing” and highly concentrated sourcing.  Because over 30% of APIs for the US market are produced in just one or two facilities globally, the system isn't just inefficient; it’s brittle. We are, in a sense, trapped in a system that prioritizes cost-reduction over the resilience required for public health. 

The researchers suggest several policy shifts to prevent a repeat of this supply chain failure: 

  1. Increased Transparency: The FDA should require manufacturers to disclose their specific API suppliers. 
  1. Risk Assessment: Identifying "vulnerable" drugs that rely on fewer than three production facilities worldwide. 
  1. Regulatory Flexibility: Streamlining the process for manufacturers to switch API suppliers during a documented national shortage. 

The ADHD medication shortage wasn't a failure of clinical oversight or a sudden surge in "TikTok-driven diagnoses”, as many have suggested. It was a failure of logistics. It reminds us that the path from a lab in Germany to a patient's hand in the US is far more precarious than we realized. 

July 6, 2026

Brain Stimulation Therapy Shows No Benefit for ADHD in New Meta-analysis

ADHD is a neurodevelopmental condition rooted in delayed or atypical maturation of the prefrontal cortex  (the brain region that governs self-regulation). This maturational lag underlies the hallmark difficulties with attention, hyperactivity, and impulsivity, and also impairs what researchers call executive function: the cognitive toolkit we rely on for working memory, impulse control, mental flexibility, emotional regulation, and the ability to tolerate delays in reward. 

The Background:

Standard treatments work through two main routes. Stimulant and non-stimulant medications are considered very safe and effective treatments, but are not without risk of side effects and are not appropriate for every ADHD patient. Behavioral and psychosocial interventions can improve self-regulation and social functioning, but they require sustained effort and produce variable results. These limitations have kept the search for better alternatives active. 

One candidate that has drawn growing attention is transcranial direct current stimulation (tDCS). The technique is appealingly simple: a weak electrical current is applied to the scalp through small electrodes, modulating the excitability of neurons in the underlying cortex without requiring surgery, anesthesia, or significant discomfort. Its safety profile and ease of use have made it attractive to researchers. 

The Study: 

A newly published meta-analysis set out to give the technique its most rigorous test yet, pooling results from randomized controlled trials, including crossover designs, that compared active tDCS against sham stimulation in people with ADHD across all age groups. 

The Results: 

The findings were consistently null. Across seven trials enrolling 303 participants, tDCS produced no significant reduction in overall ADHD symptom severity compared with sham. Breaking symptoms into their components made no difference: neither hyperactivity/impulsivity nor inattention improved. Turning to executive function, 18 studies with 872 participants found no meaningful gain in inhibitory control, and 12 studies with 506 participants found the same for working memory. Smaller bodies of evidence, including three studies on cognitive flexibility (122 participants) and two on hot executive function, the motivational and emotional dimension of self-regulation (86 participants),  similarly came up empty. Variation in outcomes across studies was small to moderate, and there was no evidence of publication bias skewing the picture. 

The authors’ conclusion was succinct: tDCS was well tolerated but “did not demonstrate significant overall efficacy for core ADHD symptoms or executive functions.” 

July 2, 2026

Children and Adolescents with ADHD Face Significantly Higher Risk of Disordered Eating, Large U.S. Study Finds

Disordered eating (a broad category of persistent, harmful patterns in eating or weight control) affects between 5% and 22% of children and adolescents worldwide, with similar rates seen in the United States. The consequences are far-reaching: these conditions are linked to bone fractures, anemia, malnutrition, dental erosion, obesity, diabetes, hypertension, and elevated cholesterol and triglycerides. They also carry one of the highest mortality rates of any psychiatric illness. 

Eating disorders rarely occur in isolation. They frequently arise alongside other psychiatric and neurological conditions. Yet, until now, no large-scale study had examined these co-occurrences in a nationally representative U.S. sample. A new study addresses that gap, focusing on children and adolescents aged 6–17 and the conditions most commonly associated with disordered eating, including ADHD. 

The Study: 

Researchers drew on data from the 2022–2023 National Survey of Children's Health (NSCH), a nationally representative, cross-sectional survey covering all 50 states and Washington, D.C. Households were selected using stratified, address-based sampling, and parents or guardians completed surveys about one randomly selected child per household. The final sample included 68,000 children and adolescents. 

Results: 

After accounting for factors including sex, age, race and ethnicity, household income, educational attainment, insurance status, and household language, children and adolescents with ADHD were 2.6 times more likely to have some form of disordered eating compared to their typically developing peers. 

The elevated risk appeared across a range of specific behaviors: 

  • 60% more likely to over-exercise 
  • Twice as likely to experience a fear of vomiting or choking 
  • 2.4 times more likely to be extremely selective eaters, to skip meals, or to fast 
  • 2.7 times more likely to purge food or vomit 
  • 3 times more likely to show little interest in food 
  • 3.2 times more likely to binge eat 

A greater tendency toward using diet pills, laxatives, or diuretics was also observed in the ADHD group, though this finding did not reach statistical significance. 

The Take-Away: 

These findings underscore a need to improve both prevention and treatment strategies for disordered eating, particularly in children and adolescents who have ADHD. Clinicians working with this population are advised to screen for a wide spectrum of disordered eating behaviors.