Concentration Difficulties That Are Not Caused by ADHD; What Should Be Checked Medically?

Sleep is essential for learning, memory, attention and cognitive control. Lack of sleep can cause distractibility, slower thinking, forgetfulness and a reduced ability to persist with tasks. Even someone who sleeps enough hours may experience poor-quality sleep, for example because of sleep apnea, frequent awakenings or disturbances in sleep timing.

In children, tiredness does not always appear as sleepiness. Sometimes it manifests instead as restlessness, irritability and behavioral difficulties.

Thyroid hormones play an important role in regulating metabolism and the functioning of the body’s systems. An underactive thyroid may manifest as tiredness, slower thinking, memory and concentration difficulties, and sometimes low mood. An overactive thyroid can cause restlessness, irritability, a rapid heartbeat and sleep difficulties, which may also affect attention.

When additional symptoms raise suspicion of a thyroid function disorder, a doctor may recommend appropriate blood tests, such as TSH and sometimes FT4.

Anemia, particularly anemia caused by iron deficiency, can lead to tiredness, weakness, headaches and concentration difficulties. Vitamin B12 deficiency may also affect neurological and cognitive functioning.

The risk of certain deficiencies may increase with a restricted diet, absorption problems, prolonged bleeding or underlying medical conditions. Depending on symptoms and risk factors, a doctor may consider a complete blood count, ferritin or B12 testing, or additional tests.

It is important to avoid taking iron supplements or high doses of vitamins without an appropriate evaluation, because not every concentration difficulty stems from a nutritional deficiency.

Hormonal changes may affect sleep quality, mood and cognitive functioning.

During adolescence, changes in sleep patterns and the biological clock may affect alertness during school hours. Women during perimenopause and menopause may report forgetfulness, difficulty finding words and a feeling of mental cloudiness, sometimes called Brain Fog. These symptoms do not necessarily indicate newly developed ADHD.

It is important to examine the overall picture, including sleep, emotional state, physical symptoms and medical history.

Certain medications can cause sleepiness, slower thinking or reduced alertness. Examples include some allergy medications, sedatives and sleep medications, some pain medications and other medications that act on the nervous system. Increased use of alcohol, cannabis or other substances may also affect memory and concentration. Sometimes the difficulty appears after starting medication, changing a dose or combining several medications.

Do not stop medication on your own. When such an effect is suspected, it is important to consult the treating doctor.

Sometimes a child who seems not to be listening is actually struggling to hear what is being said in class. Similarly, vision difficulties may lead to increased effort when reading, tiredness and avoidance of schoolwork. A child who cannot see the board clearly or struggles to distinguish speech against background noise may appear distracted, even though the primary difficulty is sensory. When relevant signs are present, vision and hearing tests can be an important part of the evaluation.

Not every concentration difficulty requires a neurological examination, but there are situations in which it is important to rule out a neurological cause. For example, repeated episodes of sudden staring accompanied by a lack of responsiveness to the surroundings may justify an evaluation to rule out certain types of seizures, such as absence seizures. Cognitive changes following a head injury, episodes of confusion or additional neurological symptoms also require medical attention. The sudden onset of significant confusion, a speech disturbance, weakness on one side of the body or an acute neurological change requires urgent medical care.

There is no standard list of blood tests that everyone must undergo before an ADHD diagnosis. The medical evaluation should be tailored to age, medical history, symptoms and the findings of the physical examination. Usually, one can start with a family doctor or pediatrician, who will assess whether laboratory tests, sensory testing, a sleep assessment or referral to a specialist are needed. When ADHD is suspected, a MOXO test may add information about attention performance, but it does not identify the medical cause of the difficulties and does not replace a medical evaluation.

The ability to concentrate is influenced by many systems in the body. Sleep, hormones, nutritional status, sensory functioning, medications and various illnesses may affect alertness and cognitive efficiency. Sometimes identifying and treating a medical cause leads to significant improvement in concentration. In other cases, the evaluation reveals several factors that affect one another.

An accurate professional assessment does not begin with the assumption that this is ADHD, but with an examination of the full range of possible explanations for the difficulty.