AuDHD Glossary
Plain-language definitions for the terms that come up most often in AuDHD, ADHD, and autism contexts. Written for understanding, not for clinical completeness.
Glossary terms
- ADHD (Attention Deficit Hyperactivity Disorder)
- A neurodevelopmental condition characterized by persistent patterns of inattention, hyperactivity, and impulsivity that interfere with functioning or development. ADHD involves differences in executive function, emotional regulation, and dopamine processing — not a deficit in attention, but inconsistent control over where attention goes. It exists on a spectrum and presents differently across individuals, ages, and genders.
- Alexithymia
- Difficulty identifying and describing one's own emotions. People with alexithymia often experience emotions physically — as sensations, tension, or discomfort — without being able to name what they are feeling. Alexithymia is significantly more common in autistic people and in those with ADHD, and contributes to patterns that can look like emotional flatness or detachment from the outside.
- ASD / Autism (Autism Spectrum Disorder)
- A neurodevelopmental condition characterized by differences in social communication, restricted or repetitive patterns of behavior, and often heightened sensory processing. The "spectrum" refers to the wide variation in how autism presents across individuals — not a linear scale from mild to severe. Autism is a different cognitive and perceptual style, not a deficiency.
- AuDHD
- The informal term for the co-occurrence of ADHD and Autism in the same person. AuDHD is not simply ADHD plus autism — the two conditions interact in ways that produce unique patterns, including mutual masking, internal contradictions, and specific challenges that neither condition creates on its own. Research estimates approximately 40% of autistic people also meet criteria for ADHD. The term is widely used in neurodivergent communities and increasingly recognized in clinical literature.
- Burnout (Autistic Burnout)
- A state of chronic exhaustion, loss of skills, and reduced tolerance to stimulus resulting from prolonged life stress and a mismatch between expectations and capacity without adequate support. Autistic burnout is distinct from occupational burnout and clinical depression. Masking is a primary risk factor. Recovery typically requires extended reduction in demands — not just rest — and may take months. AuDHD burnout is compounded because the recovery needs of each condition can conflict with each other.
- Camouflaging / Masking
- The active suppression, modification, or concealment of autistic or ADHD traits in order to appear more neurotypical. Camouflaging includes scripting social responses, mirroring others' behavior, forcing eye contact, suppressing stimming, and performing social engagement that does not come naturally. It is cognitively and emotionally costly, and long-term camouflaging is strongly associated with anxiety, depression, and autistic burnout.
- Co-occurring
- The simultaneous presence of two or more distinct conditions in the same person. In neurodevelopmental contexts, co-occurring conditions are the norm rather than the exception — ADHD and autism co-occur at rates around 40%, and both frequently co-occur with anxiety, depression, dyslexia, and other conditions. Co-occurring does not mean one condition causes or explains the other; both are independently present.
- Emotional Dysregulation
- Difficulty modulating the intensity or duration of emotional responses. In ADHD, emotional dysregulation often manifests as rapid, intense emotions that are hard to de-escalate. In autism, it may involve difficulty processing and recovering from emotional experiences, sometimes after a delay. In AuDHD, both patterns can occur, making emotional regulation particularly variable and resource-intensive.
- Executive Function
- A set of cognitive processes that manage goal-directed behavior: planning, task initiation, working memory, cognitive flexibility, inhibition, and time awareness. Executive function difficulties are central to both ADHD and autism, though they manifest differently. ADHD produces inconsistent access to these functions — they work some of the time, unreliably. Autism may involve rigid or rule-bound executive function that works well in structured contexts but struggles with ambiguity.
- Hyperfixation
- An intense, time-limited focus on a specific topic, activity, or interest, most commonly associated with ADHD. Hyperfixation differs from a special interest in its duration — it tends to be intense but temporary, cycling out when dopamine novelty fades. During a hyperfixation, other responsibilities can be neglected not out of avoidance but because cognitive resources are concentrated elsewhere. In AuDHD, hyperfixations can overlap with or cycle through special interests.
- Hyperfocus
- A state of intense, sustained concentration on a task or topic, typically in areas of interest or high stimulation. Associated primarily with ADHD, hyperfocus reflects the dysregulated attention system — attention is not absent but is inconsistently allocated. When it activates, it can produce extraordinary productivity. The difficulty is that hyperfocus cannot be reliably switched on or off, and exiting a hyperfocus state can be as difficult as entering it.
- Hyperactivity-Impulsivity
- One of the two primary symptom clusters of ADHD. Hyperactivity includes physical restlessness, fidgeting, difficulty staying seated, and a sense of internal motor drive. Impulsivity includes acting or speaking before thinking, difficulty waiting, and interrupting. In adults, hyperactivity often becomes more internal — a racing mind, emotional volatility, or difficulty slowing down — rather than the visible physical restlessness seen in children.
- Inattention
- One of the two primary symptom clusters of ADHD. Inattention includes difficulty sustaining focus on non-preferred tasks, losing track of details, forgetting steps in multi-part tasks, being easily distracted, and difficulty completing tasks that require sustained mental effort. Importantly, inattention in ADHD is inconsistent — the same person who cannot focus on a spreadsheet can hyperfocus on something engaging for hours. The issue is regulated attention, not absent attention.
- Meltdown
- An involuntary response to overwhelming neurological input or emotional overload, in which the regulatory capacity of the nervous system is temporarily exceeded. Meltdowns can involve intense emotional expression, loss of speech, crying, physical responses, or apparent behavioral dysregulation. They are not tantrums or manipulation — they are the result of a nervous system that has run out of capacity to cope with input. Recovery typically requires low-stimulation, low-demand space.
- Mutual Masking
- The phenomenon in which ADHD traits and autistic traits suppress each other's visibility, making co-occurring AuDHD harder to detect on standard single-condition screening tools. For example, autistic routine-building and focus can compensate for ADHD inattention; ADHD-driven sociability can mask autistic social communication differences. The result is a person who scores below threshold on both ADHD and autism tools individually, despite meeting criteria for both. Mutual masking is one of the primary reasons AuDHD goes unrecognized.
- Neurodivergent
- A term describing people whose neurological development and functioning differs from what is considered standard or typical. Neurodivergent encompasses ADHD, autism, dyslexia, dyspraxia, dyscalculia, Tourette syndrome, and other conditions. Coined by sociologist Judy Singer in the late 1990s as part of the neurodiversity framework, it reframes neurological difference as natural human variation rather than pathology. It is often used as a self-descriptor by people with these conditions.
- Neurotypical
- A term describing people whose neurological development and functioning falls within the range considered statistically typical or standard. Used in contrast to neurodivergent. Neurotypical is not a value judgment — it describes a statistical norm, not a superior or ideal state. In neurodivergent communities, it is often abbreviated as NT.
- Rejection Sensitivity (RSD)
- An intense emotional response to perceived rejection, criticism, failure, or disapproval — disproportionate to the triggering event and difficult to regulate once activated. Rejection Sensitive Dysphoria (RSD) is closely associated with ADHD emotional dysregulation and is also common in autistic people. It can manifest as interpreting neutral responses as negative, catastrophizing mild conflict, or experiencing anticipatory anxiety about potential rejection. RSD is not a character flaw — it reflects dysregulated neurological threat-detection.
- Sensory Processing
- The neurological process by which the brain receives, organizes, and interprets sensory input from the body and environment. Differences in sensory processing are common in autism and ADHD, including both hypersensitivity (over-responsiveness to stimuli like sound, light, texture, or smell) and hyposensitivity (under-responsiveness, sometimes manifesting as sensory-seeking behavior). These differences are not preferences — they reflect genuine differences in how the nervous system processes input.
- Shutdown
- A state of withdrawal and reduced responsiveness in reaction to overwhelming neurological input, in which the nervous system reduces activity rather than escalating it (contrasted with meltdown). Shutdowns may involve becoming non-verbal or minimally verbal, reduced movement, emotional flatness, and a need for minimal stimulation. Like meltdowns, shutdowns are involuntary responses, not choices. They are more common in people who have learned to suppress meltdown responses through masking.
- Special Interest
- An area of deep, sustained, and highly focused interest characteristic of autism. Special interests are not hobbies — they involve an intensity of engagement, knowledge accumulation, and emotional connection that goes beyond typical enthusiasm. They provide genuine joy and are often a source of significant expertise. Unlike hyperfixations, special interests tend to be stable over long periods, sometimes lasting years or a lifetime. In AuDHD, special interests may coexist with cycling hyperfixations.
- Stimming (Self-Stimulatory Behavior)
- Repetitive movements, sounds, or sensory behaviors used to self-regulate the nervous system. Common forms include hand-flapping, rocking, tapping, pacing, humming, or repetitive manipulation of objects. Stimming serves important regulatory functions — it can reduce sensory overload, manage anxiety, express emotion, or provide sensory input that the nervous system needs. It is associated with autism but also occurs in ADHD and neurotypical people. Suppressing stimming is a significant component of masking and has real neurological costs.
- Task Inertia
- Difficulty transitioning into or out of tasks — getting started on something new and stopping something already underway. Task inertia involves both the ADHD difficulty with task initiation (the neurological gap between intending to do something and actually beginning it) and an autistic preference for completing current activities before switching. In combination, task inertia can produce the AuDHD-specific stuck state: unable to start, unable to stop, caught between competing neurological demands.
A
B
C
E
H
I
M
N
R
S
T
Want more depth on any of these topics?
Our articles go deeper on the concepts that matter most for understanding AuDHD.
What Is AuDHD?
How ADHD and autism co-occur and interact.
Mutual Masking
How each condition hides the other from standard tools.
AuDHD and Relationships
Social battery, rejection sensitivity, and sustainable connection.
AuDHD at Work
Challenges, accommodations, and where AuDHD thrives.
Late Diagnosis AuDHD
Why so many adults are only discovering this now.
AuDHD Burnout
Why it differs from regular burnout, and what helps.