Agent harnesses truncate file reads around ~60k characters, so the largest dsm5 reference files (up to 132k chars) were being cut off mid-file (reported: "The neurodevelopmental file was truncated"). - Split 15 reference files over 50k chars into a small index (original filename preserved, so all existing links keep resolving) plus part files of <= ~40k chars each, organized by disorder group - Updated SKILL.md routing rows to point at indexes and read the part for the condition; added large-file handling guidance - Updated dsm5/README.md What You Get table; documented the size convention in 00-overview-and-method.md (Maintaining this library) - Verified: no reference file exceeds 50k chars (66 files), all 466 relative links resolve, validators pass, lookup.py lists all parts Co-authored-by: factory-droid[bot] <138933559+factory-droid[bot]@users.noreply.github.com>
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Cross-Cutting Differentials — DSM-5-TR Companion Reference
Summarized and paraphrased from DSM-5-TR (American Psychiatric Association, 2022). This file is for orientation and education; verify exact criteria wording, codes, and recording procedures against the official DSM-5-TR before any formal clinical, legal, insurance, or research use.
What this file is
This is the single most consulted reference when a presentation could match MULTIPLE conditions. Symptom overlap is the #1 source of confusion for laypeople and the #1 source of diagnostic error for practitioners: the same complaint — poor concentration, fatigue, insomnia, irritability, panic, odd beliefs — appears across many disorders. The DSM-5-TR itself is organized by syndromes, not by symptoms, so the same symptom is listed under many disorders; what distinguishes one condition from another is usually not the presence of a symptom but its pattern: onset, duration, course, context, and what else accompanies it.
The per-chapter references each contain a "Differential diagnosis" section. This file sits above them: it collects the overlaps that span chapters, gives a repeatable comparison method, and makes the universal rule-outs explicit. When two or more candidate conditions could explain a presentation, read this file first, then the per-chapter references named in the comparisons, then apply the method in 02-assessment-and-differential.md.
How to use this file
- Identify the candidates. Start with the symptom cluster tables in 40-cross-cutting-symptom-clusters.md. Each row names the conditions to consider for a given symptom and the chapter reference for each.
- Read the per-chapter references for each candidate condition to get the exact criteria (counts, durations, exclusions, codes).
- Run the universal rule-outs (in 40-cross-cutting-symptom-clusters.md) before attributing symptoms to a primary mental disorder.
- For the highest-value pairs, use the head-to-head tables in 40-cross-cutting-head-to-head.md, which compare the most frequently confused conditions criterion by criterion.
- Apply the comparison method in section 3 so the reasoning is repeatable and the conclusion is a set of candidates with likelihoods — never a diagnosis.
- Follow the conversation guides in 40-cross-cutting-head-to-head.md for how to talk to patients, families, and other clinicians — and when to escalate.
The comparison method
A short, repeatable procedure for any presentation that could match multiple conditions. Use the same steps every time so the reasoning is transparent and can be rechecked.
- List the candidate conditions. Use the symptom cluster tables in 40-cross-cutting-symptom-clusters.md to generate candidates from the presenting complaint. Do not stop at the first condition that comes to mind; the DSM itself notes that boundary presentations are expected and are diagnosed "in any but a probabilistic fashion."
- For each candidate, note the distinguishing criteria features. Onset (age, acute vs. insidious), duration thresholds, course (episodic vs. persistent, fluctuating vs. stable), the specific symptom count and combination required, and the exclusions built into the criteria set. Write these down next to each candidate.
- Identify which criteria appear met, unmet, or unknown. For each candidate, state explicitly: which criteria are met, which are clearly not met, and which cannot be judged yet (e.g., duration not yet elapsed, collateral history missing). An "unknown" is information to gather, not a reason to guess.
- Consider the universal rule-outs. Substances/medications, another medical condition, and (for mood/psychotic presentations) any past manic or hypomanic episode. Rule these out explicitly before settling on a primary mental disorder.
- Present the candidates with likelihood and the discriminating information. Name the most likely candidates in order, and for each state what additional information would change the ranking — a urine drug screen, a medication review, a collateral history of past episodes, a sleep study, thyroid or cardiac testing, or simply the passage of a duration threshold (e.g., symptoms persisting past 1 month converts acute stress disorder to PTSD; past 6 months converts schizophreniform disorder to schizophrenia).
- Never diagnose; present candidates and next steps. Use calibrated language ("consistent with," "most consistent with"), state explicit uncertainty, and recommend that a qualified clinician confirm before any formal diagnosis. The output of this method is a differential list and a plan, not a diagnosis.
Duration and course thresholds at a glance
Duration is the single most common discriminator. These thresholds recur across the manual and separate the overlapping candidates listed in the tables:
| Duration | Threshold applies to |
|---|---|
| 2 weeks | Major depressive episode (5 of 9 symptoms) |
| 2+ weeks without mood symptoms | Schizoaffective disorder (delusions/hallucinations without prominent mood) |
| 3 days–1 month | Acute stress disorder (9 of 14 symptoms) |
| ≥1 month | PTSD (after Criterion A exposure); manic episode (1 week minimum, unless hospitalized); delusional disorder (delusions ≥1 month); "about 1 month" persistence of symptoms after substance clearance argues for an independent disorder |
| ≥4 consecutive days | Hypomanic episode |
| 3 months | Insomnia disorder and hypersomnolence disorder (≥3 nights/days per week); bulimia nervosa and binge-eating disorder (≥1 episode/week); adjustment disorder onset window (within 3 months of stressor); IED frequency pattern (2×/week for 3 months) |
| 6 months | GAD, specific phobia, social anxiety disorder, agoraphobia (typically); somatic symptom disorder (typically >6 months); illness anxiety disorder (≥6 months); ODD (≥6 months); schizophrenia total duration (with ≥1 month active); schizophreniform (1–6 months); adjustment disorder must end within 6 months of stressor termination; persistent insomnia (>3 months) |
| 1 year | Tourette's disorder (tics >1 year); persistent (chronic) tic disorder; DMDD (12+ months in children) |
| 2 years | Persistent depressive disorder (≥2 years; ≥1 year in youth); cyclothymic disorder (≥2 years; ≥1 year in youth) |
| 12 months / 6 months in youth | Prolonged grief disorder (time since death) |
| Age thresholds | ADHD (several symptoms before age 12); ASD (early developmental period); ODD/IED (IED ≥6 years old); conduct disorder (onset subtypes by age 10); antisocial personality disorder (≥18 years, conduct disorder before 15); DMDD (first diagnosed age 6–18, onset before 10) |
Course shape also discriminates: episodic and a clear change from baseline suggests bipolar spectrum or PTSD; persistent and trait-like suggests ADHD, personality disorders, or persistent depressive disorder; acute and fluctuating suggests delirium, substance effects, or brief psychotic disorder.
Parts of this reference
| Part | Scope |
|---|---|
| 40-cross-cutting-symptom-clusters.md | Symptom cluster tables (all 14), the universal rule-outs, and a worked example of the comparison method |
| 40-cross-cutting-head-to-head.md | Head-to-head comparisons (12 pairs), conversation guides for patients, families, and clinicians, and escalation |
Cross-reference index
- Assessment method, universal exclusion, cultural formulation: 02-assessment-and-differential.md
- Safety, risk, escalation: 01-safety-and-boundaries.md
- ADHD, ASD, tics: 10-neurodevelopmental-disorders.md
- Psychotic disorders: 11-schizophrenia-spectrum-and-other-psychotic.md
- Bipolar disorders: 12-bipolar-and-related-disorders.md
- Depressive disorders: 13-depressive-disorders.md
- Anxiety disorders: 14-anxiety-disorders.md
- OCD and related: 15-obsessive-compulsive-and-related-disorders.md
- Trauma and stressor-related: 16-trauma-and-stressor-related-disorders.md
- Dissociative disorders: 17-dissociative-disorders.md
- Somatic symptom and related: 18-somatic-symptom-and-related-disorders.md
- Feeding and eating: 19-feeding-and-eating-disorders.md
- Sleep-wake disorders: 21-sleep-wake-disorders.md
- Disruptive, impulse-control, conduct: 24-disruptive-impulse-control-and-conduct-disorders.md
- Substance-related and addictive: 25-substance-related-and-addictive-disorders.md
- Neurocognitive disorders: 26-neurocognitive-disorders.md
- Personality disorders: 27-personality-disorders.md
- Medication-induced movement disorders (e.g., akathisia): 30-medication-induced-movement-disorders.md
- Other conditions that may be a focus of clinical attention (e.g., malingering is not a DSM-5-TR mental disorder and is coded in this chapter): 31-other-conditions-that-may-be-a-focus-of-clinical-attention.md