Attention-Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental condition that can affect both children and adults. It is characterised by persistent patterns of inattention and/or impulsivity and hyperactivity which impacts on daily functioning and development. The exact causes of ADHD are not yet fully understood, although research suggests that it results from a combination of genetic and environmental factors. Studies have shown that there is a strong hereditary component to ADHD, with a higher risk of having the condition when there is a history of it in the family. Certain brain structures and neurotransmitters involved in regulating attention and behaviour, such as dopamine, function differently in individuals with ADHD.

ADHD is estimated to affect approximately 6-7% of children and adolescents. Young people with the condition will sometimes (but not always) present with various challenging behaviours/conduct issues. It is important to note that ADHD can persist into adulthood, affecting around 2-5% of adults. ADHD is divided into three subgroups:

1. ADHD Predominantly inattentive presentation: This subtype is characterised primarily by difficulties concentrating and staying focused, without significant hyperactive or impulsive behaviours. (Note: This subtype was formerly known as “Attention Deficit Disorder”).
2. ADHD Predominantly hyperactive-impulsive presentation: This subtype is characterised primarily by hyperactive/impulsive behaviours, although with relatively good ability to stay focused and pay attention to topics and tasks.
3. ADHD Combined presentation: This presentation is characterised by both difficulty concentrating and staying focused, as well as significant hyperactive and impulsive behaviours. 

Research indicates that approximately 30-50% of individuals on the autism spectrum also meet the criteria for a co-morbid diagnosis of ADHD. However, it should be noted that most individuals with ADHD do not have ASD.

 

Individuals with ADHD often experience a range of issues that can impact many areas of daily life. Cognitive functions such as sustained focus, working memory, planning, multitasking, organisational skills, and impulse control are often affected. Various psychological issues, such as emotional dysregulation (irritability and outbursts of frustration), impulsivity and risk-taking, depression, and anxiety can also occur. These challenges can impact significantly on academic attainments, job performance, and social relationships.

Attention-Deficit/Hyperactivity Disorder (ADHD) is diagnosed by a psychologist or physician (medical doctor) with an expertise/specialism in ADHD and other neurodevelopmental conditions. In accordance with best-practice guidelines, a medical evaluation (including blood testing) is often requested prior to the ADHD assessment to identify or rule out any medical conditions that may be causing or contributing to an individual’s concentration and attention difficulties. The assessing clinician may also request an assessment report from an Occupational Therapist regarding the individual’s sensory processing and/or motor function.

The diagnosis of ADHD itself is made in accordance with either DSM-5 or ICD-11 criteria. Commonly used assessment tools include the Conners Rating Scales, Achenbach Rating Scales, Diagnostic Interview for ADHD (DIVA), a measure of adaptive functioning, and/or the QbTest (or some combination of these). A cognitive (IQ) assessment may also be conducted as part of the assessment to help identify the individual’s current level of cognitive ability and provide information regarding their profile of intellectual strengths and relative weaknesses.

ADHD can be treated using medications such as methylphenidate (Ritalin & Concerta) or amphetamine (Adderall), which are prescribed by a suitably qualified medical practitioner, usually a psychiatrist. These medications can enhance attention and reduce hyperactivity and impulsivity, although they may have certain side-effects.

Cognitive Behavioural Therapy (CBT) can also help individuals with ADHD manage their symptoms. This model of therapy focuses on improving self-awareness, self-control, and coping mechanisms. In addition, there is evidence suggesting that Mindfulness can also be beneficial for individuals with ADHD when used in conjunction with other evidence-based interventions.

Parents and teachers can implement a variety of strategies to help children with ADHD, such as setting clear expectations, establishing routines, providing positive reinforcement, and using techniques to help develop the child’s self-discipline and self-regulation. Furthermore, teachers can implement certain accommodations to support students with ADHD in the classroom. This may include allocated seating, providing clear and concise instructions, breaking tasks into smaller steps, and allowing for movement breaks.

 

References

Banaschewski, T., Coghill, D., & Zuddas, A. (Eds). (2018). Oxford Textbook of ADHD. Oxford University Press. Oxford: UK.

Gosling, C. J., Garcia-Argibay, M., De Prisco, M., Arrondo, G., Ayrolles, A., Antoun, S., et al. (2025). Benefits and harms of ADHD interventions: Umbrella review and platform for shared decision making. BMJ, 391:e085875. doi: 10.1136/bmj-2025-085875

Oliva, F., Malandrone, F., di Girolamo, G., Mirabella, S., Colombi, N., Carletto, S., & Ostacoli, L. (2021). The efficacy of mindfulness-based interventions in attention-deficit/hyperactivity disorder beyond core symptoms: A systematic review, meta-analysis, and meta-regression. Journal of Affective Disorders, 292, 475–486. doi.org/10.1016/j.jad.2021.05.068

Fragile X syndrome is a genetic disorder that affects both males and females, causing a range of developmental and intellectual disabilities. It is the most common inherited cause of intellectual disability and is estimated to affect about 1 in 4,000 males and 1 in 8,000 females. The aetiology (cause) of Fragile X syndrome is linked to a mutation in the FMR1 gene located on the X chromosome. As a result of this mutation, the gene does not produce enough of the protein FMRP, which is essential for normal brain development and function, particularly in the areas that control learning and behaviour. 

The symptoms of Fragile X syndrome can vary in severity and may include: 

1. Physical features: Individuals with Fragile X syndrome may have distinct physical features, such as a long and narrow face, prominent ears, and large forehead.
2. Intellectual disability: Those with the syndrome typically have some degree of intellectual disability, ranging from mild to severe.
3. Developmental delays: Children with Fragile X syndrome often have delays in reaching developmental milestones such as sitting, crawling, walking, and talking.
4. Speech and language problems: Speech and language delays, as well as difficulties with articulation and understanding complex language, are common in individuals with Fragile X syndrome.
5. Behavioural challenges: People with Fragile X syndrome may exhibit behavioural problems such as hyperactivity, attention deficit, impulsivity, anxiety, social anxiety, and aggression.

The symptoms of Fragile X syndrome and autism overlap to some extent. For example, both conditions are characterised by social difficulties, and as with ASD, individuals with Fragile X syndrome will often demonstrate some repetitive behaviours/speech patterns. In addition, intellectual disability, speech and language delays, and behavioural challenges can be present in both conditions. However, whereas Fragile X syndrome is a specific genetic disorder caused by a mutation in a single gene, autism is a more complex neurodevelopmental disorder with multiple genetic and environmental factors involved. Fragile X syndrome is relatively rare compared to autism, with the later affecting a larger percentage of the population. Unlike Fragile X syndrome, ASD is not characterised by any distinct physical features/abnormalities. It is possible for an individual with Fragile X syndrome to also meet the diagnostic criteria for ASD. 

Diagnosis of Fragile X syndrome is made through genetic testing, specifically by examining for the presence of the FMR1 gene mutation. In addition to genetic testing, doctors may also consider physical and behavioural symptoms when making a diagnosis. There are various treatment and intervention strategies available to help manage the symptoms and improve the quality of life for individuals with this Fragile X syndrome. Intervention plans can involve a combination of educational approaches, behavioural therapy, speech and language therapy, occupational therapy, and physical therapy. Medications may also be prescribed to manage specific symptoms such as anxiety, hyperactivity, or aggression. Additionally, individuals with Fragile X syndrome may benefit from support services such as special education programmes, social skills training, and counselling for both the individual and their family members.

 

Reference

Hagerman, R. J. & Hagerman, P. J. (2022). Fragile X syndrome: Lessons learned and what new treatment avenues are on the horizon. Annual Review of Pharmacology and Toxicology, 62, 365-381. doi: 10.1146/annurev-pharmtox-052120-090147

Rett Syndrome is a rare genetic disorder that predominantly affects females. It is characterised by a gradual decline in motor skills, slowed growth, and a loss of communicative abilities and other acquired skills after a period of seemingly normal development. Rett Syndrome results from mutations in the MECP2 gene, although other gene mutations have also been identified as causes in a small percentage of cases. 

The symptoms of Rett Syndrome can start to emerge from about 6 months onwards, often becoming more pronounced between 12-18 months. Some of the key symptoms include: 

1. Loss of purposeful hand skills: Children with Rett Syndrome often lose their ability to perform previously acquired hand movements, such as grasping objects or using utensils.
2. Regression of acquired skills: Individuals with Rett Syndrome experience a regression in their overall development, including the loss of speech and social engagement. They may also exhibit a decline in motor skills.
3. Breathing abnormalities: Many individuals with Rett Syndrome develop irregular breathing patterns, such as hyperventilation, breath-holding episodes, or apnea during sleep.
4. Motor difficulties: People with Rett Syndrome often have difficulties with coordination and gait, as well as repetitive movements such as hand-wringing or hand-flapping.
5. Intellectual disability: Rett Syndrome is associated with varying degrees of intellectual disability, ranging from mild to severe.

While ASD may sometimes involve a degree of regression of acquired skills (such as language and social engagement), in Rett Syndrome the regression is typically more severe and rapid. Rett Syndrome is much rarer than ASD and predominantly affects females, whereas studies show that ASD tends to more commonly diagnosed in males. Furthermore, Rett Syndrome is primarily caused by a single gene mutation, whereas autism is a complex neurodevelopmental disorder with multiple genetic and epigenetic factors involved.

Rett Syndrome is diagnosed through genetic testing and clinical observations and evaluations. While there is currently no cure for Rett Syndrome, treatment and intervention strategies focus on managing symptoms and improving the individual’s quality of life. The management of Rett Syndrome often involves a multidisciplinary approach, which can include some or all of the following professional: paediatricians, neurologists, physiotherapists, occupational therapists, speech & language therapists, and behavioural therapists. Additionally, behavioural interventions and educational support are often implemented to help develop the social skills and cognitive abilities of individuals with Rett Syndrome. Medications may also be used as part of the treatment plan.

 

Reference

Liyanage, V. R. B. & Rastegar, M. (2014). Rett Syndrome and MeCP2. Neuromolecular Medicine, 16(2), 231–264. doi:10.1007/s12017-014-8295-9