If this isn’t ADHD, then what is it? A dozen conditions that can mimic ADHD
“Things are not always as they seem; the first appearance deceives many,” said Phaedrus, Roman Poet 15BC-50 AD. This famous saying couldn’t be truer for the clinical condition ADHD (Attention Deficit Disorder), as there are a dozen medical conditions that can mimic ADHD. To complicate matters further many of these conditions discussed below can co-exist with ADHD.
In recent years, the news headlines have declared an ‘epidemic’ of ADHD overdiagnosis. Unfortunately, though this hysteria is not new, such disingenuous narratives are a harmful misrepresentation of the truth; they dismiss the very real impact of ADHD on those with the condition, further the incorrect assumption that ADHD can be ‘simulated’ and underestimate the difficulty of obtaining a diagnosis.
While there has been a significant increase in the number of children diagnosed with ADHD, this is largely—and thankfully—due to an increased awareness of the symptoms of ADHD amongst clinicians and patients. ADHD in children, sadly remains under-identified, under-diagnosed, and under-treated in the UK.
Though I feel that the fear over ADHD overdiagnosis in children is overblown, it’s crucial that your child is accurately and comprehensively assessed as part of a neurodevelopmental assessment by a trained healthcare professional.
A comprehensive neurodevelopmental assessment is also important so that conditions that may possibly mimic ADHD—and hence complicate diagnosis and treatment—are excluded. In many cases, these conditions can be comorbid with ADHD (i.e. they appear together), and it’s important that these are all identified and appropriately treated.
But First…What Is ADHD Exactly?
ADHD (Attention Deficit Hyperactivity Disorder) is a behavioural syndrome characterised by three core symptoms: inattention, hyperactivity, and impulsivity. For a diagnosis, several manifestations (criteria) of these symptoms should have been present for at least six months, be age-inappropriate, and should have resulted in significant psychological, social, educational, or functional impairment. Symptoms typically appear in children aged 3 to 7 years and should be present in at least two settings e.g. at home, school, out-of-school activities, or in social situations. You can find more information about ADHD, in the article I wrote “Warning Signs of ADHD.”
An ADHD diagnosis and management of the condition requires a comprehensive assessment by a trained specialist e.g. a neurodevelopmental paediatrician, a child psychiatrist, etc. The treatment options offered depend on the child’s age and the extent of impact of the condition on their lives, and could include parent education/support programmes, group or individual psychological treatment e.g. CBT, and treatment with medications, such as methylphenidate, lisdexamfetamine or atomoxetine. It’s therefore important that other causes for ADHD-mimicking symptoms are excluded, as part of the neurodevelopmental assessment.
A dozen conditions that can mimic as or be present with ADHD:
In this article, we’ll go through what the alternative diagnoses could be, as various neurodevelopmental and behavioural disorders, medical conditions, sensory impairments, and psychiatric/mental health disorders, can present as ADHD. Many of these below mentioned conditions can also present with ADHD (co-morbid), further complicating the clinical presentation. And so, the conditions that mimic ADHD are as follows:
- Oppositional Defiant Disorder
Oppositional defiant disorder (ODD) is a behavioural disorder characterised by a pattern of uncooperative, defiant, and hostile behaviours towards authority figures. These include frequent temper tantrums, excessive arguing, and spitefulness. These behaviours can resemble ADHD due to overlapping symptoms like impulsivity, hyperactivity, and disruptive behaviours. Diagnosing these conditions can be challenging due to the symptom overlap, between ADHD and ODD. While ADHD-related behaviours are typically unintentional and due to difficulties with self-regulation, and will appear across various settings, ODD-related behaviours are often deliberate and directed at defying authority.
- Conduct Disorder
Conduct disorder (CD) is a behavioural disorder in children characterised by a persistent pattern of aggressive, deceitful, or destructive behaviours e.g. bullying, physical fights, theft, vandalism, and a disregard for rules and the rights of others. Both CD and ADHD can manifest as disruptive behaviours, impulsivity, and difficulty following the rules, leading to challenges in various settings, such as at home or school. However, ADHD is primarily characterised as inattentiveness, hyperactivity, and impulsivity due to neurological factors, whereas CD involves deliberately aggressive and antisocial behaviour, intended to violate rules and rights, which children with just ADHD, do not typically display. You can find more information in the article “Top 10 strategies to manage behaviour problems in children with Autism and ADHD”.
- Autism Spectrum Disorder
Autism spectrum disorder (ASD) is a neurodevelopmental condition characterised by difficulties with communicating and interacting with others, having restricted interests, displaying repetitive behaviours, and having sensory sensitivities that impact day-to-day functioning, etc. Both ASD and ADHD can co-exist in significant proportion of children and young people. Children with either ASD or ADHD or both, may struggle with focus, appear restless, and have difficulty following instructions. However, ADHD alone is primarily marked by inattention and hyperactivity without typically much difficulty socially, whereas children with ASD can face greater challenges with social interactions, social communication and have restricted interests and activities.
- Learning difficulties
Learning difficulties refer to a range of disorders that affect the ability to acquire and use academic skills, such as reading (dyslexia), writing (dysgraphia), and maths (dyscalculia). Learning difficulties can be distinguished from learning disabilities (LD) by the effect on intellectual ability. Learning difficulties or learning delay can be due to genetic factors, neurological differences, prenatal, perinatal, and post-natal factors, developmental delays, psychological factors such as anxiety, depression, and trauma, and health issues that interfere with learning by causing frequent absences from school or affecting a child’s concentration or memory.
Both learning difficulties and ADHD can result in poor academic performance, inattentiveness, and frustration in school settings e.g. struggling to follow instructions, complete tasks, and stay organised, thus mimicking each other. However, as mentioned above, while ADHD presents with symptoms of inattentiveness, hyperactivity, and impulsivity across various settings, children with learning difficulties typically are mainly affected in academic settings, where they struggle more with information processing rather than general control of their attention and impulse.
- Vision impairment
Vision impairment refers to a partial or total loss of vision that cannot be corrected with standard glasses or contact lenses. Depending on the extent of loss of vision, from mild impairment to complete blindness, this can significantly impact a child’s daily functioning. Children may display behaviours that can resemble ADHD, such as difficulty concentrating or appearing restless and fidgety. However, these behaviours are not due to neurological differences as seen in ADHD, but rather, from difficulty seeing and processing visual information, leading to frustration and distraction.
- Hearing impairment
Hearing impairment refers to a partial or total loss of hearing ability, and depending on the extent of loss, can significantly impact the ease of communication and social interactions. Similarly to as described above under vision impairment, children can display ADHD-like behaviours, such as restlessness and inattentiveness, but this is borne out of the child’s frustration with struggling to hear and process auditory information, in contrast to an underlying struggle with controlling their attention.
- Sleep Impairments and Disorders
Sleep impairment refers to disruptions in the quantity, quality or timing of sleep, and can include difficulties falling asleep, staying asleep, or waking too early, as well as other sleep disorders. Children with sleep impairments may show symptoms of daytime sleepiness, irritability, difficulty concentrating, and behavioural problems, which may resemble the symptoms of ADHD.
- Epilepsy
Epilepsy is a neurological disorder characterised by recurrent seizures—sudden, brief changes in the electrical activity of the brain. They can appear as convulsions, sudden loss of consciousness, or staring into space. During and after a seizure, a child can appear confused, disoriented, or have trouble focusing, which may rarely be mistaken for ADHD.
- Thyroid Conditions
Thyroid conditions are disorders affecting the thyroid gland, a small gland in the neck that produces several important hormones for the body. These conditions include hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid). Hypothyroidism, in particular, can share symptoms with ADHD e.g. difficulties with concentration, mood changes, and forgetfulness. However, in contrast to ADHD which impairs daily functioning across various settings, the symptoms in thyroid disorders may fluctuate based on thyroid hormone levels. Moreover, there is presence of several other signs and symptoms of hypothyroidism in children, such as, slowing of growth rate, fatigue, constipation, swollen hands, feet and face, etc.
- Anxiety and Depression
Anxiety disorder (Anxiety in children with Autism and ADHD) involves excessive worry, fear, or nervousness that can interfere with daily functioning. Symptoms may include restlessness, irritability, and an inability to concentrate, alongside more physical manifestations such as sweating and a rapid heart rate. Depression is a mood disorder characterised by persistent sadness, loss of interest in activities, fatigue, changes in appetite, disrupted sleep, and difficulty concentrating. Both conditions can impact an individual’s ability to self-regulate their emotions and their overall mood and mental health. Hence, both anxiety and depression can present with symptoms that overlap with ADHD.
- Bipolar disorder
Other mood disorders, such as bipolar disorder, can also be mistaken for ADHD or appear alongside it (as a co-morbid condition). Bipolar disorder is characterised by extreme highs (mania or hypomania) and extreme lows (depression), with symptoms ranging from hyperactivity, restlessness, impulsivity, increased energy to sadness, fatigue, and loss of interest in activities. Hence, the manic symptoms of bipolar disorder can resemble the hyperactivity and impulsivity seen in children with ADHD. However, ADHD involves persistent patterns of its core symptoms of inattention, hyperactivity, and impulsivity that affect daily functioning across different settings, whereas bipolar disorder involves distinct episodes of mania/hypomania and depression.
- Substance misuse
Last but not the least, is substance misuse. This involves the harmful or hazardous use of substances such as alcohol, tobacco, prescription medications, or illicit drugs. It can lead to behaviours similar to those seen in ADHD, such as recklessness, poor decision-making, and impaired judgement.
Conclusion
Therefore, to arrive at a correct diagnosis, it is crucial to undertake a detailed and comprehensive history, including, pregnancy, birth, family and past medical history, supplemented with a head-to-toe physical examination including neurological examination, together with reports and rating scales completed by parent(s) and a child’s teacher.
Accurate diagnosis is essential for effective treatment of ADHD. Thankfully, there are several effective medical and non-medical interventions to help minimise the impact of ADHD on a given child’s social functioning and academic learning. We recommend trial of non-medical measures involving behavioural, educational and environmental interventions for a period of at least 6 months, before medical interventions are considered. You can read more about these interventions in the article ‘Tips to improve attention in children with ADHD, ASD and Dyspraxia’. Misdiagnosis of ADHD can lead to not only inappropriate treatment, but distress for the child and family and lost opportunities to fulfil once’s potential. Nevertheless, as seen above, there are various conditions that can overlap and appear co-morbidly with ADHD, which can complicate diagnosis and treatment. Therefore, a comprehensive neurodevelopmental assessment completed by a trained healthcare professional is crucial.
