In This Article

Introduction: A Relationship That Clinical Systems Have Mostly Refused to Examine

Why the overlap between bipolar disorder, autism, and ADHD has been systematically underdiscussed, what that silence has cost, and what an honest account requires.

PART ONE: The Historical and Diagnostic Context

I. How These Diagnoses Were Built

The separate developmental histories of bipolar disorder, autism, and ADHD as diagnostic categories, how the frameworks were built on different populations with different assumptions, and why the categories were designed to be mutually exclusive.

II. The Diagnostic Criteria Problem

What happens when diagnostic criteria developed primarily from observations of white, male, and institutionalized populations are applied to women, to late-identified adults, and to people with multiple co-occurring conditions.

III. The Exclusion Clause History

The history of diagnostic systems explicitly excluding autistic and ADHD people from mood disorder diagnoses, why those exclusions existed, and what happened when they were revised.

PART TWO: The Symptom Overlap

IV. Emotional Dysregulation: The Most Consequential Overlap

RSD, autistic emotional intensity, and ADHD emotional impulsivity alongside bipolar mood episodes: what they share in presentation, how they differ in mechanism, and why the difference is clinically significant.

V. The Energy Cycle: Boom, Bust, and What Drives Each

ADHD boom-bust cycles, autistic burnout and recovery, and bipolar cycling: the surface similarities and the mechanistic distinctions, and why getting this wrong changes the entire treatment approach.

VI. Hyperfocus, Hypomanic Productivity, and the Confusion Between Them

What distinguishes ADHD hyperfocus from bipolar hypomania, the features that overlap in presentation, and the features that distinguish them when examined carefully.

VII. The Dark Periods: Shutdown, Paralysis, and Depression

Autistic shutdown, ADHD paralysis, burnout depletion, and bipolar depression: what each looks like, what drives each, and the critical differences that determine what would actually help.

VIII. Racing Thoughts, Impulsivity, and Risk-Taking

How racing thoughts present differently in ADHD, in anxiety, and in bipolar mania; ADHD impulsivity versus bipolar impulsivity; and what the grandiosity question actually reveals.

IX. Sleep, Sensory Experience, and the Somatic Dimension

Sleep disruption in both populations, sensory processing differences and how they interact with mood, and what the body’s experience of these states reveals that behavioral observation misses.

PART THREE: The Misdiagnosis Pipeline

X. Who Gets Which Diagnosis and Why

The documented patterns in who receives bipolar diagnoses versus autism and ADHD diagnoses, the demographic variables that shape clinical assessment, and the specific populations most vulnerable to misdiagnosis.

XI. Why Women Are Especially Vulnerable

The intersection of gender bias in clinical settings, the female autism and ADHD presentation differences that evade standard assessment, masking and its suppression of diagnostic signals, and what the combined effect produces in clinical encounters.

XII. The Masking Problem in Diagnostic Settings

How masking performs neurotypicality in the clinical encounter, why the most thoroughly masked people are the most thoroughly misdiagnosed, and what the clinical environment’s own design contributes to the problem.

XIII. The Trauma Variable

How complex PTSD produces presentations that resemble both bipolar disorder and autism and ADHD, why trauma history is consistently underassessed in diagnostic processes, and what disentangling the three actually requires.

XIV. The Medication History as Diagnostic Evidence

What the history of medication responses reveals about the original diagnosis, how treatment failure or adverse response to mood stabilizers and antipsychotics functions as retrospective diagnostic information, and what that information should do in clinical practice.

PART FOUR: Genuine Co-Occurrence

XV. When Both Are Present: The Evidence

What the research literature shows about the genuine co-occurrence of bipolar disorder and AuDHD, why co-occurrence is both more common and more often missed than clinical practice acknowledges, and what the interaction between them produces.

XVI. What Co-Occurring Bipolar and AuDHD Actually Looks Like

The specific clinical presentation of co-occurring conditions, why it is more complex than either condition alone, and what distinguishes it from misdiagnosis in both directions.

XVII. The Treatment Complexity of Co-Occurrence

What treating co-occurring bipolar disorder and AuDHD requires, why standard treatment protocols for each condition are insufficient when both are present, and what an integrative approach would need to include.

PART FIVE: The Structural and Justice Analysis

XVIII. The Clinician Training Gap

What most clinicians were taught about the relationship between bipolar disorder and autism and ADHD, what the actual evidence shows, and what the gap between training and evidence produces in practice.

XIX. Epistemic Injustice in the Diagnostic Encounter

Whose accounts of their own experience are treated as credible, how the diagnostic process systematically disadvantages the populations most vulnerable to misdiagnosis, and what epistemic injustice looks like in the clinical context specifically.

XX. What the Misdiagnosis Cost

The Neurodiversity Justice analysis: what years of wrong diagnosis and wrong treatment produce in a person’s life, what the cumulative harm looks like, and where the accountability for it belongs.

XXI. The Race and Class Dimensions

How racial bias, class-based access to diagnostic services, and the specific intersection of race and autism and ADHD shape who receives which diagnosis, and what the documented disparities reveal about the diagnostic system’s design.

PART SIX: Toward Accurate Understanding

XXII. What Differential Diagnosis Actually Requires

The features that actually distinguish bipolar disorder from autism and ADHD, the assessment process that would actually capture them, and why current standard practice falls short of that process.

XXIII. Questions That Clarify

The specific clinical and self-assessment questions that help distinguish mood disorder from autistic and ADHD presentations, and what the answers reveal when they’re asked honestly and in full context.

XXIV. If You Suspect Misdiagnosis or Co-Occurrence

What to do with the suspicion, how to approach the existing clinical relationship, what to look for in a diagnostic re-evaluation, and what to expect from the process.

XXV. Community, Peer Knowledge, and the Limits of Clinical Authority

What autistic and ADHD community has produced in terms of framework for this overlap that clinical systems haven’t provided, and what the limits of peer knowledge are relative to the limits of clinical authority.

Conclusion: The Diagnosis Is a Tool, Not a Verdict

What an accurate diagnostic framework should do, what it cannot do, and what the person in the middle of an uncertain diagnostic picture is owed by the systems that created the uncertainty.

A Note on Crisis Resources

If any part of this article has surfaced difficult experiences: where to find support.

Introduction: A Relationship That Clinical Systems Have Mostly Refused to Examine

There is a population of people who spent years, sometimes decades, being treated for bipolar disorder who were not bipolar. There is a population of people who are both bipolar and autistic or ADHD whose autism and ADHD were never identified because the bipolar diagnosis absorbed all available clinical attention. And there is a population of people for whom both conditions are present, interacting, and producing a clinical picture that neither diagnosis alone adequately captures, who are receiving treatment calibrated to one condition and wondering why it isn’t fully working.

These three populations are not small. They are not edge cases. They are the produced outcome of a diagnostic system that developed its categories in separate institutional silos, that built its assessment tools on inadequate samples, that trained clinicians in frameworks that treat mood disorders and neurodevelopmental conditions as mutually exclusive rather than as frequently overlapping, and that has been especially poor at recognizing the specific presentations of women, people of color, late-identified adults, and anyone whose clinical picture doesn’t match the prototype on which the diagnostic criteria were based.

This article is the account of that relationship: the historical, the clinical, the mechanistic, and the justice dimensions of what happens at the intersection of bipolar disorder, autism, and ADHD. It covers the symptom overlaps and their underlying distinctions. It examines the misdiagnosis pipeline and who it targets. It takes the genuine co-occurrence seriously rather than treating it as a diagnostic impossibility. It holds the structural analysis of what the misdiagnosis has cost and where the accountability belongs. And it offers something honest about what accurate understanding, in either the clinical or the personal context, actually requires.

A note before proceeding: this article discusses mood episodes, suicidality statistics, and the consequences of misdiagnosis and inadequate treatment. If any of that is difficult content at this moment, please read at a pace that serves you, and please see the note on crisis resources at the end.

PART ONE: The Historical and Diagnostic Context

I. How These Diagnoses Were Built

Bipolar disorder, autism, and ADHD share a historical feature that is directly relevant to their current relationship: all three were built as diagnostic categories primarily from observations of specific, unrepresentative populations, and the criteria that resulted reflect those populations’ presentations rather than the full range of how each condition actually manifests.

Bipolar disorder as a clinical category has its roots in the nineteenth century, in Emil Kraepelin’s influential distinction between dementia praecox, which became schizophrenia, and manic-depressive insanity, which became the precursor to bipolar disorder. Kraepelin’s observations were drawn from institutionalized patients whose episodes were severe, whose presentations were dramatic, and whose baseline functioning between episodes was observable primarily within the institutional context rather than in ordinary life. The resulting framework emphasized the most extreme presentations: the full manic episode with florid symptoms, the severe depressive episode with psychomotor changes, the cyclical alternation between identifiable poles. The subtler presentations, hypomania that doesn’t look dramatically different from someone’s normal high-functioning period, cyclothymia, rapid cycling, the bipolar presentations that are most likely to be missed or mistaken for something else, were built into the framework later and with less institutional weight behind them.

Autism’s diagnostic history is substantially a history of observing male children in clinical and educational settings, and the criteria Leo Kanner and Hans Asperger developed in the 1940s reflected the presentations of the specific children they observed, who were male, who had sufficient verbal and cognitive capacity to be subjects of clinical study, and whose autistic traits expressed themselves in the ways that were readable to mid-twentieth-century clinicians. The autistic girls in those same settings were less often referred, less often studied, and less often included in the frameworks that resulted. The autistic women who came much later to clinical attention, including those receiving diagnoses in adulthood, presented in ways that the criteria built from Kanner’s and Asperger’s observations were not designed to capture, and the decades of misdiagnosis that resulted were the direct consequence of applying the wrong template.

ADHD’s diagnostic history has its own version of the same problem: a diagnostic category built primarily from observations of hyperactive boys in classroom settings, producing criteria that emphasized the most externally visible features of the condition, the motor hyperactivity, the disruptive behavior, the observable inattention that interfered with teachers’ management of classrooms. The inattentive presentation that is more common in girls, the internalized version of ADHD that doesn’t produce the external behavioral signals the criteria were built to detect, the ADHD that looked like daydreaming and emotional sensitivity and organizational difficulty rather than climbing the furniture, was systematically missed by criteria designed around the most disruptive male expression of the condition.

These three diagnostic histories converge on the same structural problem: categories built from limited samples, applied to the full human population, producing systematic misidentification of everyone whose presentation doesn’t match the founding prototype. The relationship between bipolar disorder, autism, and ADHD is, in significant part, a relationship produced by these shared historical limitations and by what happens when the diagnostic errors they generate accumulate across a person’s clinical history.

II. The Diagnostic Criteria Problem

Diagnostic criteria in psychiatry and psychology function as checklists of observable behaviors and reported experiences that must be present at specified levels for a specific duration to qualify for a diagnosis. That structure has genuine utility for establishing inter-rater reliability and for providing a shared clinical language, but it has a significant limitation that is directly relevant to the bipolar-autism-ADHD overlap: behavioral criteria describe what the condition looks like from the outside, not what produces it from the inside, and the same external behavior can be produced by very different internal mechanisms.

A person who experiences intense, rapid emotional responses that shift her mood dramatically within hours might be presenting with bipolar cycling, with rejection sensitive dysphoria, with the emotional dysregulation that characterizes ADHD, with the emotional intensity of autistic experience, with the emotional instability of a trauma response, or with some combination of all of these. The behavioral criterion, rapid mood shifts with high emotional intensity, does not distinguish between them. The mechanism that produces the behavior is different in each case, the treatment appropriate to each is different, and the prognosis for each is different, but the criterion captures only the surface and assigns the same diagnostic weight to all of its possible sources.

This surface-behavior-capture problem is compounded by the fact that psychiatric diagnostic criteria were developed in environments where the assessor was a clinician and the assessed was a patient, and the clinician’s interpretation of the patient’s presentation was filtered through the clinician’s training, the clinician’s preexisting expectations, and the demographic assumptions embedded in the clinical culture. When the patient is a woman, the clinician’s interpretation of her emotional intensity is affected by cultural assumptions about women’s emotionality that don’t apply equally to male patients. When the patient is Black, the clinician’s interpretation of her behavior is affected by racial stereotypes that have documented effects on clinical judgment. When the patient is masking her autism or ADHD effectively, the clinician is assessing a performed presentation rather than the actual clinical picture, and the assessment will reflect the performance rather than the reality.

III. The Exclusion Clause History

For much of the twentieth century, diagnostic systems explicitly built in exclusion clauses that prevented mood disorder diagnoses from being applied when a neurodevelopmental condition was present. The reasoning, to the extent it was made explicit, was that the behavioral and emotional features that would otherwise qualify for a mood diagnosis were better explained by the neurodevelopmental condition, and that the mood diagnosis therefore added nothing clinically useful. This reasoning had a surface plausibility that made it durable, and it produced a generations-long clinical assumption that autism and bipolar disorder didn’t meaningfully co-occur, that the emotional and mood features of autistic presentations were autistic features rather than mood disorder features, and that the diagnostic question in any given case was which one category was operating rather than whether multiple categories were simultaneously relevant.

The DSM-III, published in 1980, was especially influential in entrenching categorical exclusions, and the hierarchical diagnostic structure it established, in which some diagnoses trumped others and the presence of one precluded consideration of another, shaped a generation of clinical training. Clinicians trained in that framework approached autism- or ADHD-presenting patients with the assumption that the neurodevelopmental diagnosis explained what they were seeing, and that mood disorder features within that presentation required no additional diagnostic consideration.

The DSM-5, published in 2013, made significant revisions to several of these exclusions, including removing the prohibition on dual diagnosis of autism and ADHD that had been in the DSM-IV. These revisions acknowledged what the accumulated research had been showing for years: that the conditions co-occur at rates that the exclusion framework had made invisible, and that treating them as mutually exclusive had been producing systematic diagnostic failure for a significant population of patients. But revisions to the diagnostic manual do not automatically produce revisions to clinical practice, and many clinicians continue to operate from frameworks built before the revisions, applying categorical exclusions that the current evidence doesn’t support.

PART TWO: The Symptom Overlap

IV. Emotional Dysregulation: The Most Consequential Overlap

Emotional dysregulation is the single most consequential area of overlap between bipolar disorder, autism, and ADHD, and it is where the most diagnostic harm has been done, because it is the feature that most directly sends autistic and ADHD people to mood disorder evaluations in the first place, and it is also the feature that is most poorly distinguished by current standard assessment practices.

In bipolar disorder, mood episodes represent state-level changes in the person’s entire functional presentation: shifts in energy, sleep need, cognition, goal-directedness, and emotional tone that persist for days to weeks and that represent a departure from the person’s typical baseline. The mood episode in bipolar disorder is not primarily a response to environmental triggers; it can occur in the absence of any identifiable precipitant, and it persists across changing circumstances. The person in a hypomanic episode does not return to their typical baseline when the situation that might have seemed to precipitate the elevation resolves. The person in a depressive episode does not lift to their baseline when circumstances improve.

Rejection Sensitive Dysphoria, the neurological response to perceived rejection or criticism that is characteristic of ADHD and common in AuDHD more broadly, produces intense, rapid emotional responses that can superficially resemble mood cycling. The RSD episode, however, is fundamentally different in its mechanics: it is triggered, it is acute, and it resolves, usually within hours, when the triggering perception is addressed or when the nervous system’s response cycle completes. The emotional intensity during the RSD episode can be extreme, the behavioral responses can be dramatic, and the person experiencing it may describe it in terms that sound like mood episodes to a clinician who is listening for bipolar symptoms. But the time course, the trigger-responsiveness, and the resolution pattern are all different from the mood episode structure of bipolar disorder.

Autistic emotional intensity is distinct from both. Autistic people frequently experience emotions at higher intensity and with less automatic regulation than neurotypical people, which can produce presentations that look like emotional instability from the outside but that are, from the inside, the experience of feeling things fully in a world that expects partial engagement with difficult feelings. The autistic person who melts down in response to sensory overload or social overwhelm is not experiencing a mood episode. She is experiencing the nervous system’s response to genuine overwhelm, and the meltdown, like the RSD episode, is trigger-responsive, resolves when the trigger is addressed or the nervous system has discharged the activation, and does not represent a change in her baseline mood state.

The clinical significance of getting this distinction right is substantial. The autistic or ADHD person who receives a bipolar diagnosis because of her emotional intensity may be prescribed mood stabilizers or antipsychotics that carry significant side effect profiles and that are not calibrated to what is actually driving her presentation. She may organize her self-understanding around a framework that doesn’t fit, which distorts her account of her own experience in ways that compound the original misdiagnosis. She may not receive the support that would actually help: the ADHD treatment that would address the RSD, the autistic-affirming framework that would reduce the shame and self-blame contributing to her emotional distress, the sensory and environmental accommodations that would reduce the overwhelm producing the meltdowns.

V. The Energy Cycle: Boom, Bust, and What Drives Each

The energy cycles of ADHD, autistic burnout, and bipolar disorder are sufficiently similar in surface presentation to be consistently confused in clinical assessment, and sufficiently different in mechanism that their treatment implications are almost opposite.

ADHD energy cycles are primarily driven by the dopamine economy of the ADHD nervous system: the variable relationship between available dopamine and task engagement produces boom periods when interest, urgency, or emotional salience supply the activation that the task’s intrinsic reward doesn’t, and bust periods when the activation sources are depleted, the interest has moved on, or the hyperfocus that powered the boom has exhausted both the engagement and the available neurological resources. The ADHD cycle is responsive to the interest economy: it shifts when the interest landscape shifts. It does not follow the episodic, state-change structure of bipolar cycling, and it does not produce the characteristic bipolar features of elevated self-esteem, decreased need for sleep while maintaining high energy, and goal-directed activity with subjective urgency that characterizes hypomania.

Autistic burnout is a specific physiological state that develops from the cumulative depletion of sustained masking, sensory overload, and social performance beyond the nervous system’s sustainable load. The burnout state is characterized by loss of previously held skills and functions, increased sensory sensitivity, reduced capacity for social interaction, and a recovery timeline that can extend to months or years. It is not a depressive episode in the bipolar sense; it does not involve the neurovegetative features of major depression such as psychomotor retardation, guilt, or suicidal ideation as primary features, though it can include low mood as a secondary consequence of the depletion. The critical diagnostic distinction is temporal: burnout develops gradually from accumulating depletion, recovers gradually with reduced demand and increased support, and does not alternate with periods of elevated energy, reduced sleep need, or the other features of hypomanic or manic episodes.

Bipolar cycling, including the rapid cycling that is present in a significant minority of bipolar diagnoses, produces state-level changes in energy that are qualitatively different from both the ADHD interest economy and the burnout depletion. The hypomanic or manic energy state involves elevated energy that does not depend on interest engagement, reduced need for sleep without a corresponding increase in fatigue, increased goal-directedness and productivity often across multiple domains simultaneously, decreased need for external structure, and a subjective experience of heightened capacity and urgency that the person in the state often does not recognize as a departure from their baseline. The depressive state involves the reverse: global reduction in energy, motivation, and capacity regardless of interest engagement, often accompanied by psychomotor changes and neurovegetative symptoms that the ADHD crash and the burnout state do not consistently produce.

VI. Hyperfocus, Hypomanic Productivity, and the Confusion Between Them

The confusion between ADHD hyperfocus and bipolar hypomania is one of the most common sources of misdiagnosis in this population, and it calls for careful examination because the two states can be nearly identical in behavioral presentation while being fundamentally different in mechanism, duration, and clinical significance.

ADHD hyperfocus is the intense, absorptive engagement with a topic or task that the ADHD interest-based attention system produces when a subject fully captures the nervous system’s engagement. During hyperfocus, the person may work for many consecutive hours without registering fatigue, hunger, or the passage of time; may produce work at a quality and pace that exceeds their ordinary output; may feel a sense of heightened engagement and capability; and may resist interruption with unusual intensity. The hyperfocus state requires the subject of the focus to be engaging; it cannot be directed toward tasks that don’t capture the interest system, and it dissipates when the interest dissipates or when the task is complete.

Bipolar hypomania shares several of these surface features: elevated energy and productivity, reduced need for sleep, heightened sense of capability, and difficulty with voluntary interruption of the elevated state. But the mechanistic differences are significant. Hypomania is not driven by interest engagement; it is a state-level change that produces elevated energy and productivity regardless of what the person is doing, that does not require a compelling subject to sustain it, and that can be directed toward any domain the person turns their attention toward rather than being captured by a specific subject. The hypomanic person may produce at high output across multiple domains simultaneously, may initiate multiple projects without the constraint of specific interest, and may experience the elevation as mood-syntonic, as simply how she is when she is functioning at her best.

The features that most reliably distinguish the two states clinically, when assessed carefully, include: the relationship to sleep (hyperfocus is compatible with normal sleep need; hypomania involves reduced sleep need often alongside maintained or increased energy), the domain specificity (hyperfocus is interest-constrained; hypomania is domain-general), the relationship to the person’s typical baseline (hyperfocus is recognizable as a feature of the person’s ordinary functioning; hypomania represents a departure from the usual baseline that others who know the person well can often identify), and the aftermath (hyperfocus resolves into ordinary ADHD functioning; the post-hypomanic period in bipolar disorder is often followed by a depressive descent that is absent from the ADHD hyperfocus cycle).

VII. The Dark Periods: Shutdown, Paralysis, and Depression

The clinical distinction between the low periods of AuDHD experience and bipolar depression is among the most clinically consequential and most poorly made distinctions in the assessment of this population. All three, autistic shutdown, ADHD paralysis, and burnout, can present with features that superficially match major depressive episode criteria, and the consequences of treating neurological depletion with antidepressants calibrated for mood disorder are different from, and sometimes significantly worse than, the consequences of leaving mood disorder depression untreated.

Autistic shutdown is the nervous system’s response to overwhelming input: a withdrawal of social engagement and communicative capacity, reduced sensory tolerance, and a turning inward that can look, from the outside, like depression or withdrawal or affective flattening. The person in shutdown may not speak, may not respond to usual social approaches, may appear profoundly dysphoric. But the shutdown is not a mood state; it is a neurological protection response, and it resolves when the overwhelming input is reduced and the nervous system has sufficient recovery time. The appropriate response to autistic shutdown is environmental modification and reduction of demands, not antidepressant medication or mood-stabilizing intervention.

ADHD paralysis, the state of being unable to initiate or sustain action despite the presence of tasks that need doing, can persist for extended periods and can co-occur with low mood, frustration, shame, and the secondary depressive features that develop when the paralysis prevents the person from meeting obligations and living in accordance with her values. The underlying mechanism is executive function and dopamine dysregulation rather than mood disorder; it is the ADHD nervous system’s failure to generate the activation that initiation requires, compounded by the shame architecture that develops around the repeated experience of that failure. Antidepressants sometimes provide modest benefit for the low mood associated with ADHD paralysis, but they do not address the underlying mechanism, and the treatment that reliably addresses ADHD paralysis is ADHD-specific intervention.

Bipolar depression is qualitatively different from both of these in ways that can be identified when the assessment is thorough. It involves neurovegetative symptoms: changes in appetite and weight, sleep alterations that go beyond the ADHD’s already-disrupted sleep, psychomotor changes that are observable rather than only self-reported, and a global reduction in hedonic capacity that the autistic shutdown and ADHD paralysis don’t consistently produce. It also typically occurs in the context of a history that includes episodes of elevated mood, energy, and reduced sleep need, and the episodic pattern of the mood disorder, the identifiable cycles of elevation and depression with recognizable transitions between them, is often visible in longitudinal history even when it isn’t obvious in a cross-sectional clinical encounter.

VIII. Racing Thoughts, Impulsivity, and Risk-Taking

Racing thoughts are reported by a significant proportion of people with ADHD, a significant proportion of people with anxiety disorders, and a significant proportion of people in bipolar hypomanic or manic states, and the clinical literature has not been sufficiently precise about what distinguishes them.

ADHD racing thoughts are typically experienced as multiple simultaneous streams of loosely associated content: ideas, tasks, worries, observations, and memories running in parallel rather than in sequence, producing a crowded mental landscape that is experienced as either stimulating or exhausting depending on the valence of the content and the person’s current state. The thoughts do not typically have the elevated urgency and goal-directedness of hypomanic racing thoughts; they are often unpleasant, intrusive, or distracting rather than subjectively energizing, and they are not typically accompanied by the subjective sense of accelerated processing or exceptional clarity that characterizes the hypomanic state.

Bipolar hypomanic and manic racing thoughts have a different quality: they are experienced as faster than usual, as producing connections at an elevated rate, often as felt exciting or significant rather than intrusive, and they are accompanied by the pressure of speech and the urgency to communicate or act on the ideas that characterize the elevated state. The racing thoughts of mania carry a sense of meaning and significance that the ADHD racing thoughts don’t consistently have, and they are embedded in the broader hypomanic or manic state rather than being an isolated feature.

Impulsivity is similarly multidetermined. ADHD impulsivity is driven by deficits in inhibition: the ADHD nervous system’s difficulty suppressing prepotent responses produces behavior that acts before the full consequences have been processed, speech that arrives before the thought has been fully formed, decisions made without adequate deliberation. Bipolar impulsivity during hypomania or mania is driven differently: by elevated goal-directedness and the subjective experience of opportunity, by reduced access to the anxiety and caution that ordinarily constrain behavior, and by the subjective sense that the elevated state’s judgment is more reliable than the baseline judgment rather than less. The bipolar person in a hypomanic state is not failing to inhibit a response; she is responding to a perceived opportunity that the elevated state makes feel compelling and reasonable in ways that the post-episode perspective will not share.

Autistic risk-taking, when it occurs, is often a different phenomenon from either: the autistic person who engages in behavior that others read as reckless may be acting from a different assessment of risk rather than from impaired inhibition or elevated state judgment, may be responding to a sensory or motivational driver that others don’t have access to, or may be less calibrated to social risk norms in ways that produce behavior that reads as impulsive without being the product of impaired impulse control.