Neurodevelopmental Disorders

Neurodevelopmental disorders are common, and rates of diagnosis are increasing, at least partially because doctors are becoming better at recognizing them.^[1]

Key takeaways

• Neurodevelopmental disorders include a wide range of disorders typically diagnosed during childhood that result from a combination of genetic, biological, and environmental factors

• Neurodevelopmental disorders are very common, and many children experience more than one

• Much of the treatment for neurodevelopmental disorders focuses on helping children and adults learn how to best manage their condition

Understanding neurodevelopmental disorders

Neurodevelopmental disorders begin in childhood, although symptoms may not become apparent until later. Children with one of these disorders have altered or delayed development, which can impact their personal, social, or intellectual growth.^[2]The scope and severity of the difficulty vary widely.

Neurodevelopmental disorders are lifelong conditions that a child is born with, which set them apart from acquired conditions, such as PTSD.^[3]These conditions aren’t necessarily entirely genetic, however. Most neurodevelopmental disorders are multifactorial, with genetic, biological, and environmental factors. For some conditions, brain alterations may be present from birth, but symptoms may remain below diagnostic thresholds without environmental contributions. Where symptoms do develop, this usually occurs before puberty.

Types of neurodevelopmental disorders

There is some disagreement among researchers as to which disorders are considered neurodevelopmental. Conditions that are widely considered to be neurodevelopmental disorders include attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), learning disabilities, communication disorders, and motor disorders.^[3]Other conditions, such as conduct disorders and cerebral palsy, are considered neurodevelopmental disorders by some researchers, but not according to DSM-5V (the primary diagnostic manual for psychological disorders), where conduct disorders are classified as disruptive and impulse control-related conditions..^[2][4]

Prevalence of neurodevelopmental disorders

Estimates based on parental responses put the rate of neurodevelopmental conditions at approximately 15% in the US.^[4]The prevalence of some conditions, such as autism spectrum disorder (ASD), do appear to be increasing, although it is hard to be sure about this because we’re also getting better at identifying and supporting people with them condition.^[5]

There is a high level of co-occurrence between different neurodevelopmental disorders, meaning that a child living with one of these conditions may well have others.^[3]Some researchers consider that co-occurrence is more common than singular presentation.^[6]

Neurodevelopmental disorders are consistently diagnosed more often in males than in females.^[7]For some conditions, such as ASD, this may reflects a diagnostic bias, as well as a true underlying discrepancy.^[8]

History of neurodevelopmental disorders

Neurodevelopmental disorders were first recognized in the US as “developmental disabilities” in 1970.^[6]Initially, this included severe developmental delays (which used to be referred to as mental retardation), but it was later renamed neurodevelopmental disabilities, and the definition was expanded to include chronic conditions that began in childhood and affected the central nervous system (CNS).

Internationally, developmental disorders were first included in the third edition of the Diagnostic and Statistical Manual.^[9]

Many neurodevelopmental disorders used to be thought of as limited to childhood, because the symptoms reduce or change as individuals mature. This is now understood to be inaccurate, with conditions such as ADHD, specific learning disorder, and ASD continuing into adulthood.^[3]

Causes of neurodevelopmental disorders

The causes of neurodevelopmental disorders are typically complex. In some rare cases, they can be based on a single gene, but they are more likely to be based on interactions between genetics, biology, and environmental factors.^[10]While some researchers are trying to identify different potential causes and the relationships between them, others suspect that there may be a single underlying cause for neurodevelopmental conditions. causes for an individual neurodevelopmental disorder, such as ASD, but others suspect that there may be a single underlying cause behind many of these conditions.^[11][12]

Neurodevelopmental disorders and the brain

Although the exact causes of neurodevelopmental disorders aren’t properly understood, they stem from dysfunction in the structure and/or functioning of the brain.^[12]Most researchers agree that neurodevelopmental disorders stem from disruptions to brain development early in life.^[13]

Symptoms of neurodevelopmental disorders

The symptoms of neurodevelopmental disorders vary widely, depending on the specific condition and individual in question. Below are some of the more common neurodevelopmental disorders and the symptoms associated with them.

Some symptoms have different names depending on the disorder they are associated with. In other cases, the same name is used to describe very different symptoms.^[6]

ADHD

There are three present categories of symptoms of ADHD: inattention and hyperactivity/impulsivity, and combined type. Someone with ADHD may have predominantly inattentive symptoms (inattentive type ADHD), only hyperactive/impulsive symptoms (hyperactive type ADHD), or experience a mixture of symptoms (combined).^[14]

Common inattentive symptoms of ADHD include:

• Struggle to sustain attention

• Forgetfulness

• Disorganization

Common hyperactive or impulsive symptoms of ADHD include:

• Fidgeting

• Restlessness

• Interrupting

• Excessive talking

Autism Spectrum Disorder

There are two main categories of symptoms of ASD: social communication and interaction and restrictive or repetitive behavior or interests.^[15]

Examples of social communication symptoms of ASD include:

• Difficulty with social cues

• Unusual language development

• Struggles to share or take turns

Examples of symptoms associated with restrictive behavior include:

• Emotional dysregulation

• Upset by minor changes

• Special interests

Specific learning disorder

Specific learning disorders are typically characterized by delayed development in a particular area compared with other children of a similar age. Signs that a child may have a specific learning disorder include:^[16]

• Struggling with tasks such as reading or math

• Being easily distracted

• Poor memory

• Disorganization

• Difficulty following instructions

• Clumsiness

Common learning disorders include dyslexia (difficulty reading), dysgraphia (difficulty writing), and dyscalculia (difficulty with math).

Communication disorders

These are problems related to language and speech. There is a wide range of symptoms in this category, but they include:^[17]

• Repeating sounds

• Struggling to make sounds

• Pausing during speech

• Using many fillers (such as umm and err)

• Using words in an incorrect order

• Speaking too loudly or indistinctly

• Struggling to understand rapid speech

Most children with a communication disorder will have some, but not all, symptoms.

Motor disorders

This category of neurodevelopmental disorders includes developmental coordination disorder, stereotypic movement disorder, and tic disorders (such as Tourette Syndrome’s).^[18]

Developmental coordination disorder is characterized by clumsiness and poor motor control. Symptoms of stereotypic movement disorder and tic disorders include unusual behaviors, such as flapping hands, rocking the body, sudden vocalizations, or unexpected jerky movements.

Diagnosing neurodevelopmental disorders

ADHD

Diagnosing ADHD will typically require a clinical interview with a licensed mental health professional, psychiatrist, or ADHD specialist. The provider will collect information, including medical history, family history, and current and historical symptoms and experiences. They will evaluate those symptoms to determine whether someone meets the criteria for an ADHD diagnosis, and if so, what type.

They will be looking to see how many symptoms someone has from each of the inattentive and hyperactive, or impulsive categories. This will determine both whether they are diagnosed with ADHD and which type of ADHD they are diagnosed with. Providers may also use self-reports and rating scales in addition to a clinical interview to measure and identify symptoms.^[19]

For adults, an ADHD diagnosis will often also include discussions of childhood experiences, as the interviewer tries to understand whether these symptoms have been present throughout their lifetime. Interviews with trusted loved ones who have observed the individual, like a parent or partner, may also be included.

Autism Spectrum Disorder

A diagnosis of ASD will also require a clinical interview with a specialist. In this case, the provider will ask questions about the child’s behavior and development, and they will also observe and make their own clinical evaluation of the child’s behavior. Similar to diagnosing ADHD, rating scales, self-reports, and interviews with trusted individuals who have observed the behaviors may be included as part of the evaluation process.

For a diagnosis of ASD, the provider doctor must see evidence of deficits in social or emotional behavior, deficits in non-verbal communication skills, and deficits in relationships, as well as several examples of restricted or repetitive patterns of behavior, interests, or activities.^[20]

For adults, the process is broadly similar, with patients being assessed across several interactions as well as being asked to self-report their symptoms.

Specific Learning Disorder

Diagnosis of a specific learning disorder will usually happen in cooperation with a child’s school. Their progress is monitored, compared to their peers, and considered in the context of their social and emotional development. The process of evaluation includes current symptoms and experiences, family history, observations, and often school reports.

In most cases, a doctor or other medical professional is asked to conduct a full medical assessment of the child to ensure that there are no other disorders or conditions that might explain their difficulties. Where appropriate, this could include ADHD or ASD assessments for exclusionary purposes.

Communication disorders

Communication disorders are also diagnosed through clinical interviews and observations. During diagnosis, a clinician is looking for signs that a child is struggling with communication, which can include spoken, written, or sign language. They will explore whether the child spontaneously uses speech and how well they understand communication.^[17]

Once difficulties in communication have been identified, the clinician will check that the problems can’t be explained by sensory problems, such as hearing loss, or other neurodevelopmental disorders, such as a specific learning disorder.

Motor disorders

Diagnosis of a motor disorder is usually carried out by a specialist. They compare a child’s motor skills to those expected of a child of the same age and speak to parents, teachers, and caregivers.^[18]

When diagnosing a motor disorder, clinicians also need to take into consideration the child’s overall health and development. Poor handwriting, for example, can be the result of a motor disorder or a learning disability. They may ask about a child’s organizational skills and ability to perform a variety of tasks to distinguish between a motor disorder and other neurodevelopmental problems.

The impact of neurodevelopmental disorders on families

Neurodevelopmental disorders don’t just affect the child. who has them. Often, the whole family learns to adapt to the child’s condition. Parents and caregivers, in particular, may experience increased stress, social stigma, and self-blame.^[21][22]

For children, there are positive and negative aspects to having a sibling with a neurodevelopmental disorder. They are at risk of feeling overlooked or deprioritized, but they can also develop advanced emotional skills and empathy.^[23]

Therapeutic treatment for neurodevelopmental disorders

As childhood-onset, congenital conditions, there is little that can be done to avoid or prevent neurodevelopmental disorders after birth. Measures such as reducing maternal nicotine and alcohol use during pregnancy can reduce the risk of several neurodevelopmental disorders, including ASD and ADHD.^[24]

In most cases, however, treatment for neurodevelopmental disorders focuses on teaching individuals skills to compensate for their difficulties and providing accommodations to minimize the effects of their condition.

Cognitive behavioral therapy

Some research shows that there are benefits to using CBT with children and adolescents with conditions like ADHD. CBT is used with older children who have ADHD, but younger children lack the cognitive development to benefit. Depending on a child’s age, cognitive development, and needs, behavioral therapy may be better-suited for some children with neurodevelopmental conditions. For those children, behavioral therapy is used. In most cases, the best results come when parents are also given specific training on how to support their child with their diagnosis.^[45]

Habit reversal therapy

For children with tic disorders or stereotypic movement disorder, a type of CBT known as habit reversal therapy (HRT) can be used. HRT uses the fact that most people with tics or involuntary movements can recognize when a tic is about to occur (premonitory urges). Children are then trained to respond to those urges with other behaviors that prevent the tic.^[18]

Psychosocial treatments for ASD

Psychological treatments aimed at helping children with ASD often focus on breaking down social or communicative tasks into component skills. Efforts are made to encourage emotional development, including awareness of their own emotions and those of others.^[25]

Group therapy

Group therapy can be used for several different neurodevelopmental disorders and can offer children a chance to interact with peers who live with similar conditions or experiences. For instance, children with ASD can use group therapy to connect with others. Those with communication disorders can practice communication in a judgment-free environment.^[17]

Physical education

Research suggests that experiencing visible symptoms of neurodevelopmental conditions can feel burdensome or stigmatizing.^[18]Physical therapy is used to help children with developmental coordination disorder learn fine motor control. This training involves a combination of learning strategies to achieve difficult motor tasks, such as tying shoelaces, and provides a safe environment for practicing motor skills. By reducing or eliminating visible signs of the disorder, children can feel more confident among their peers and experience improved self-esteem.^[18]

Speech therapy

Children with communication disorders may participate in speech therapy focused on their specific needs. This can include physical vocal training (including tongue twisters), fluency exercises, and more.^[17]

Phonics training

Children with dyslexia might be offered training in language and writing construction to help them predict or ‘work out’ the words they are reading.^[26]Similar programs can be offered to children with dyscalculia to help them with the basic principles of mathematics at a pace that is appropriate to their needs.

Medication treatment for neurodevelopmental disorders

In addition to psychosocial support and learning coping strategies, some neurodevelopmental disorders are also treated with medication. Stimulants, non-stimulants, and other medications are frequently prescribed for children with ADHD.^[19]Less commonly, selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants, and antipsychotics can be offered to children with some movement disorders.^[18]

Final thought

Neurodevelopmental disorders are lifelong conditions that typically start in childhood. Children with these disorders can often thrive, but help and support are essential for the best outcomes.