The increasing prevalence of Attention Deficit Hyperactivity Disorder (ADHD) diagnoses has prompted experts to urge caution, warning that symptoms such as restlessness, trouble concentrating, and memory problems could stem from other, more easily treatable medical conditions. In England, an estimated 2.5 million people have ADHD, with diagnoses doubling over the past two decades, particularly among adults.

Professor Dinesh Bhugra, former president of the Royal College of Psychiatrists, stressed the importance of accurate diagnosis. "It's vitally important that people get the right diagnosis," he stated. "Giving them stimulants when they don’t need them is not going to help, and we don’t yet know the long-term consequences of being on these drugs." He added that professionals should look beyond symptom checklists and consider multiple facets of a patient's health.

A 2023 review by Canadian psychiatrist Joseph Sadek identified several conditions that may be misdiagnosed as ADHD, including thyroid issues and iron deficiency. The review concluded that comprehensive medical evaluations are crucial before an ADHD diagnosis is made.

Dr. Dan Baumgardt, a GP and senior lecturer at the University of Bristol, noted that ADHD symptoms typically manifest in childhood and persist throughout life. "Symptoms of ADHD don’t generally appear in adulthood – there’s usually a trail that leads back to childhood as it’s a lifelong condition," he explained. "If symptoms suddenly appear, it becomes more likely there’s another cause which should be investigated."

Potential Mimicking Conditions

Several conditions can present with symptoms similar to ADHD:

Blood Sugar Issues

Diabetes, particularly type 1 and type 2, can lead to fatigue and cognitive issues, including problems with memory and attention, which may resemble ADHD. Both types can be identified through a simple blood test.

Thyroid Disorders

Both underactive (hypothyroidism) and overactive (hyperthyroidism) thyroid conditions can cause symptoms like brain fog, fatigue, difficulty concentrating, and restlessness. These are common and can be detected via blood tests. Hormonal changes during perimenopause can also contribute to similar symptoms, especially if they appear for the first time in midlife.

Mental Health Conditions

Depression and anxiety can blur diagnostic lines with ADHD, causing poor concentration, lack of motivation, restlessness, and racing thoughts. Distinguishing between these conditions requires professional expertise, as treatments differ significantly.

Iron Deficiency

Low iron levels, common especially among women, can cause poor concentration, inattention, and memory problems. This is easily treatable with supplements or infusions. Dr. Sue Pavord, a hematologist at the University of Oxford, recommends screening for iron deficiency in anyone being assessed for ADHD, noting its prevalence in children and young adults.

Sleep Disorders

Insufficient sleep or conditions like obstructive sleep apnoea can affect attention and lead to hyperactivity in children, potentially mimicking ADHD symptoms. The American Academy of Pediatrics advises screening for sleep problems in those seeking ADHD assessments.

Experts emphasize that a thorough assessment should consider the onset of symptoms, their impact on daily life, and whether other underlying conditions could be responsible for the presentation. This approach ensures patients receive the correct diagnosis and most effective treatment.