Attention deficit hyperactivity disorder in the context of Sensory processing disorder

Inhibitory control, also known as response inhibition, is a cognitive process – and, more specifically, an executive function – that permits an individual to inhibit their impulses and natural, habitual, or dominant behavioral responses to stimuli (a.k.a. prepotent responses) in order to select a more appropriate behavior that is consistent with completing their goals. Self-control is an important aspect of inhibitory control. For example, successfully suppressing the natural behavioral response to eat cake when one is craving it while dieting requires the use of inhibitory control.

The prefrontal cortex, caudate nucleus, and subthalamic nucleus are known to regulate inhibitory control cognition. Inhibitory control is impaired in both addiction and attention deficit hyperactivity disorder. In healthy adults and ADHD individuals, inhibitory control improves over the short term with low (therapeutic) doses of methylphenidate or amphetamine. Inhibitory control may also be improved over the long-term via consistent aerobic exercise.

Neuropsychiatry is a branch of medicine that deals with psychiatry as it relates to neurology, in an effort to understand and attribute behavior to the interaction of neurobiology and social psychology factors. Within neuropsychiatry, the mind is considered "as an emergent property of the brain", whereas other behavioral and neurological specialties might consider the two as separate entities. Those disciplines are typically practiced separately.

Currently, neuropsychiatry has become a growing subspecialty of neurology as it closely relates the fields of neuropsychology and behavioral neurology, and attempts to utilize this understanding to better understand psychological trauma, autism, attention deficit hyperactivity disorder (ADHD), and Tourette syndrome, among others.

Autism, also known as autism spectrum disorder (ASD), is a condition characterized by differences or difficulties in social communication and interaction, a need or strong preference for predictability and routine, sensory processing differences, focused interests, and repetitive behaviors. Characteristics of autism are present from early childhood and the condition typically persists throughout life. Autism is classified as a neurodevelopmental disorder, and a formal diagnosis requires professional assessment that these characteristics cause significant challenges in daily life beyond what would be expected given a person's age and social environment. Because autism is a spectrum disorder, presentations vary and support needs range from minimal to the person being non-speaking or needing 24-hour care.

Autism diagnoses have risen since the 1990s, largely because of broader diagnostic criteria, greater awareness, and wider access to assessment. Changing social demands may also play a role. The World Health Organization estimates that about 1 in 100 children were diagnosed between 2012 and 2021, noting an increasing trend. Surveillance studies suggest a similar share of the adult population would meet diagnostic criteria if formally assessed. This rise has fueled anti-vaccine activists' disproven claim that vaccines cause autism, based on a fraudulent 1998 study that was later retracted. Autism is highly heritable and involves many genes, while environmental factors appear to play a smaller, mainly prenatal role. Boys are diagnosed several times more often than girls, and conditions such as anxiety, depression, attention deficit hyperactivity disorder (ADHD), epilepsy, and intellectual disability are more common among autistic people.

Congenital insensitivity to pain (CIP), also known as congenital analgesia, is an inability for a person to feel physical pain due to various rare genetic conditions. CIP is caused by genetic mutations that affect the development or function of nociceptors, the sensory neurons in the brain responsible for recognizing tissue damage. Common symptoms include damage to the oral cavity, repeated bone fractures, and sometimes the inability to sweat. Some forms of CIP are also correlated with intellectual disabilities, learning disabilities, or attention deficit hyperactivity disorder (ADHD). Hereditary sensory autonomic neuropathies (HSAN) fall under the umbrella of CIP. Methods of treatment are still being explored. The epidemiology of CIP is unclear, given the relatively low number of reported cases.

Dysgraphia is a neurological disorder and learning disability that concerns impairments in written expression, which affects the ability to write, primarily handwriting, but also coherence. It is a specific learning disability (SLD) as well as a transcription disability, meaning that it is a writing disorder associated with impaired handwriting, orthographic coding and finger sequencing (the movement of muscles required to write). It often overlaps with other learning disabilities and neurodevelopmental disorders such as speech impairment, attention deficit hyperactivity disorder (ADHD) or developmental coordination disorder (DCD).

In the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), dysgraphia is not mentioned. Dyslexia is characterized as a neurodevelopmental disorder under the umbrella category of specific learning disorder.

Neurodevelopmental disorders are a group of mental conditions negatively affecting the development of the nervous system, which includes the brain and spinal cord. According to the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) published in 2013, these conditions generally appear in early childhood, usually before children start school, and can persist into adulthood. The key characteristic of all these disorders is that they negatively impact a person's functioning in one or more domains of life (personal, social, academic, occupational) depending on the disorder and deficits it has caused. All of these disorders and their levels of impairment exist on a spectrum, and affected individuals can experience varying degrees of symptoms and deficits, despite having the same diagnosis.

The DSM-5 classifies neurodevelopmental disorders into six overarching groups: intellectual, communication, autism, attention deficit hyperactivity, motor, and specific learning disorders. Often one disorder is accompanied by another.

The neurodiversity paradigm is a framework for understanding human brain function that considers the diversity within sensory processing, motor abilities, social comfort, cognition, and focus as neurobiological differences. This diversity falls on a spectrum of neurocognitive differences. The neurodiversity movement views autism as a natural part of human neurological diversity—not a disease or a disorder, just "a difference".

Neurodivergences include autism, attention deficit hyperactivity disorder (ADHD), bipolar disorder (BD), developmental prosopagnosia, developmental speech disorders, dyslexia, dysgraphia, dyspraxia, dyscalculia, dysnomia, intellectual disability, obsessive–compulsive disorder, schizophrenia, sensory processing disorder (SPD), synesthesia, and Tourette syndrome.

Hyperfocus is an intense form of mental concentration or visualization that focuses consciousness on a subject, topic, or task. In some individuals, various subjects or topics may also include daydreams, concepts, fiction, the imagination, and other objects of the mind. Hyperfocus on a certain subject can cause side-tracking away from assigned or important tasks.

Psychiatrically, it is considered to be a trait of attention deficit hyperactivity disorder (ADHD) together with inattention, and it has been proposed as a trait of other conditions, such as schizophrenia and autism spectrum disorder (ASD).

Urinary incontinence (UI), also known as involuntary urination, is any uncontrolled leakage of urine. It is a common and distressing problem, which may have a significant effect on quality of life. Urinary incontinence is common in older women and has been identified as an important issue in geriatric health care. The term enuresis is often used to refer to urinary incontinence primarily in children, such as nocturnal enuresis (bed wetting). UI is an example of a stigmatized medical condition, which creates barriers to successful management and makes the problem worse. People may be too embarrassed to seek medical help and attempt to self-manage the symptom in secrecy from others.

Pelvic surgery, pregnancy, childbirth, attention deficit hyperactivity disorder (ADHD), and menopause are major risk factors. Urinary incontinence is often a result of an underlying medical condition but is under-reported to medical practitioners. There are four main types of incontinence:

Dyslexia, also known as "word blindness", is a learning disability that affects either reading or writing. Different people are affected to different degrees. Problems may include difficulties in spelling words, reading quickly, writing words, "sounding out" words in the head, pronouncing words when reading aloud and understanding what one reads. Often these difficulties are first noticed at school. The difficulties are involuntary, and people with this disorder have a normal desire to learn. People with dyslexia have higher rates of attention deficit hyperactivity disorder (ADHD), developmental language disorders, and difficulties with numbers.

Dyslexia is believed to be caused by the interaction of genetic and environmental factors. Some cases run in families. Dyslexia that develops due to a traumatic brain injury, stroke, or dementia is sometimes called "acquired dyslexia" or alexia. The underlying mechanisms of dyslexia result from differences within the brain's language processing. Dyslexia is diagnosed through a series of tests of memory, vision, spelling, and reading skills. Dyslexia is separate from reading difficulties caused by hearing or vision problems or by insufficient teaching or opportunity to learn.

Methylphenidate, sold under the brand name Ritalin and Concerta, among others, is a central nervous system (CNS) stimulant used in the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. It may be taken by mouth or applied to the skin, and different formulations have varying durations of effect. For ADHD, the effectiveness of methylphenidate is comparable to atomoxetine but modestly lower than amphetamine. Methylphenidate reduces core ADHD symptoms and may do so in part by enhancing cognitive control of behavior (i.e., working memory and inhibitory control).

At therapeutic doses, methylphenidate increases alertness and concentration and reduces hyperactivity and impulsive behavior in individuals with ADHD. Common side effects include loss of appetite, weight loss, trouble sleeping, and small increases in heart rate and blood pressure. Long-term treatment in children has been associated with slightly slower growth. Methylphenidate can be misused; dependence and withdrawal are mainly reported with high-dose or non-medical use and are uncommon at therapeutic doses.

Amphetamine is a central nervous system (CNS) stimulant that is used in the treatment of attention deficit hyperactivity disorder (ADHD), narcolepsy, and obesity; it is also used to treat binge eating disorder in the form of its inactive prodrug lisdexamfetamine. Amphetamine was discovered as a chemical in 1887 by Lazăr Edeleanu, and then as a drug in the late 1920s. It exists as two enantiomers: levoamphetamine and dextroamphetamine. Amphetamine properly refers to a specific chemical, the racemic free base, which is equal parts of the two enantiomers in their pure amine forms. The term is frequently used informally to refer to any combination of the enantiomers, or to either of them alone. Historically, it has been used to treat nasal congestion and depression. Amphetamine is also used as an athletic performance enhancer and cognitive enhancer, and recreationally as an aphrodisiac and euphoriant. It is a prescription drug in many countries, and unauthorized possession and distribution of amphetamine are often tightly controlled due to the significant health risks associated with recreational use.

The first amphetamine pharmaceutical was Benzedrine, a brand which was used to treat a variety of conditions. Pharmaceutical amphetamine is prescribed as racemic amphetamine, Adderall, dextroamphetamine, or the inactive prodrug lisdexamfetamine. Amphetamine increases monoamine and excitatory neurotransmission in the brain, with its most pronounced effects targeting the norepinephrine and dopamine neurotransmitter systems.

Clinical neuroscience is a branch of neuroscience that focuses on the scientific study of fundamental mechanisms that underlie diseases and disorders of the brain and central nervous system. It seeks to develop new ways of conceptualizing and diagnosing such disorders and ultimately of developing novel treatments.

A clinical neuroscientist is a scientist who has specialized knowledge in the field. Not all clinicians are clinical neuroscientists. Clinicians and scientists -including psychiatrists, neurologists, clinical psychologists, neuroscientists, and other specialists—use basic research findings from neuroscience in general and clinical neuroscience in particular to develop diagnostic methods and ways to prevent and treat neurobiological disorders. Such disorders include addiction, Alzheimer's disease, amyotrophic lateral sclerosis, anxiety disorders, attention deficit hyperactivity disorder, autism, bipolar disorder, brain tumors, depression, Down syndrome, dyslexia, epilepsy, Huntington's disease, multiple sclerosis, neurological AIDS, neurological trauma, pain, obsessive-compulsive disorder, Parkinson's disease, schizophrenia, sleep disorders, stroke and Tourette syndrome.

Alertness is a state of active attention characterized by high sensory awareness. Someone who is alert is vigilant and promptly meets danger or emergency, or is quick to perceive and act. Alertness is a psychological and physiological state.

Lack of alertness is a symptom of a number of conditions, including narcolepsy, attention deficit hyperactivity disorder, chronic fatigue syndrome, depression, Addison's disease, and sleep deprivation. Pronounced lack of alertness is an altered level of consciousness. States with low levels of alertness include drowsiness.

Dyscalculia is a learning disability resulting in difficulty learning or comprehending arithmetic, such as difficulty in understanding numbers, numeracy, learning how to manipulate numbers, performing mathematical calculations, and learning facts in mathematics. It is sometimes colloquially referred to as "math dyslexia", though this analogy can be misleading as they are distinct syndromes.

Dyscalculia is associated with dysfunction in the region around the intraparietal sulcus and potentially also the frontal lobe. Dyscalculia does not reflect a general deficit in cognitive abilities or difficulties with time, measurement, and spatial reasoning. Estimates of the prevalence of dyscalculia range between three and six percent of the population. In 2015, it was established that 11% of children with dyscalculia also have attention deficit hyperactivity disorder (ADHD). Dyscalculia has also been associated with Turner syndrome and people who have spina bifida.

Methamphetamine is a central nervous system (CNS) stimulant that is primarily used as a recreational or performance-enhancing drug and less commonly as a second-line treatment for attention deficit hyperactivity disorder (ADHD). It has also been researched as a potential treatment for traumatic brain injury. Methamphetamine was discovered in 1893 and exists as two enantiomers: levo-methamphetamine and dextro-methamphetamine. Methamphetamine properly refers to a specific chemical substance, the racemic free base, which is an equal mixture of levomethamphetamine and dextromethamphetamine in their pure amine forms, but the hydrochloride salt, commonly called crystal meth, is widely used. Methamphetamine is rarely prescribed over concerns involving its potential for misuse as an aphrodisiac and euphoriant, among other concerns, as well as the availability of other drugs with comparable effects and treatment efficacy such as dextroamphetamine and lisdexamfetamine. While pharmaceutical formulations of methamphetamine in the United States are labeled as methamphetamine hydrochloride, they contain dextromethamphetamine as the active ingredient. Dextromethamphetamine is a stronger CNS stimulant than levomethamphetamine.

Both racemic methamphetamine and dextromethamphetamine are illicitly trafficked and sold owing to their potential for recreational use and ease of manufacture. The highest prevalence of illegal methamphetamine use occurs in parts of Asia and Oceania, and in the United States, where racemic methamphetamine and dextromethamphetamine are classified as Schedule II controlled substances. Levomethamphetamine is available as an over-the-counter (OTC) drug for use as an inhaled nasal decongestant in the United States and is seldom abused. Internationally, the production, distribution, sale, and possession of methamphetamine is restricted or banned in many countries, owing to its placement in schedule II of the United Nations Convention on Psychotropic Substances treaty. While dextromethamphetamine is a more potent drug, racemic methamphetamine is illicitly produced more often, owing to the relative ease of synthesis and regulatory limits of chemical precursor availability.

Autism, also known as autism spectrum disorder (ASD), is a condition characterized by differences or difficulties in social communication and interaction, a need or strong preference for predictability and routine, sensory processing differences, focused interests, and repetitive behaviors. Characteristics of autism are present from early childhood and the condition typically persists throughout life. Autism is classified as a neurodevelopmental disorder, and a formal diagnosis requires professional assessment that these characteristics cause significant challenges in daily life beyond what would be expected given a person's age and social environment. Because autism is a spectrum disorder, presentations vary and support needs range from minimal to the person being non-speaking or needing 24-hour care.

Autism diagnoses have risen since the 1990s, largely because of broader diagnostic criteria, greater awareness, and wider access to assessment. Changing social demands may also play a role. The World Health Organization estimates that about 1 in 100 children were diagnosed between 2012 and 2021, noting an increasing trend. Surveillance studies suggest a similar share of the adult population would meet diagnostic criteria if formally assessed. Autism is highly heritable and involves many genes, while environmental factors appear to play a smaller, mainly prenatal role. Boys are diagnosed several times more often than girls, and conditions such as anxiety, depression, attention deficit hyperactivity disorder (ADHD), epilepsy, and intellectual disability are more common among autistic people.