Psychiatric diagnosis Study Guide

📖 Core Concepts Mental disorder – a clinically recognizable set of symptoms/behaviors causing distress and functional impairment (ICD‑11, DSM‑5‑TR). Distress – subjective emotional suffering reported by the patient; required for a formal diagnosis. Functional impairment – inability to meet expected roles (work, school, relationships). Categorical (Neo‑Kraepelinian) schemes – place disorders into discrete boxes; aim for high inter‑rater reliability. Dimensional/spectral schemes – view symptoms on continuous scales; capture sub‑threshold and overlapping presentations. Hybrid models – combine categorical labels with dimensional severity (e.g., DSM‑5‑TR personality disorder work‑group). ICD‑11 – WHO’s global system (effective 1 Jan 2022); chapters organized by disorder type; emphasizes cultural sensitivity. DSM‑5‑TR – US‑based authority (2022 revision); detailed criteria, severity specifiers, primary tool for billing & research. RDoC – NIMH research framework; organizes mental illness by neurobiological domains (e.g., Negative Valence, Cognitive Systems) rather than diagnostic categories. --- 📌 Must Remember Core diagnostic rule: Both distress and functional impairment must be present (ICD‑11, DSM‑5‑TR). DSM‑5‑TR 2022 updates: Asperger → autism spectrum Schizophrenia subtypes eliminated Bereavement exclusion removed for depression Gender Identity Disorder → Gender Dysphoria Binge‑eating disorder added as distinct eating disorder Paraphilias → Paraphilic disorders Five‑axis system removed (since DSM‑IV) ICD‑11 vs DSM‑5‑TR: Same core categories, but ICD‑11 codes are alphanumeric (e.g., 6A70 for major depressive disorder) and embed a stronger cultural lens. Categorical vs Dimensional: Categorical = “yes/no” label; Dimensional = score on a continuum (e.g., severity rating 0‑3). RDoC units of analysis: genes → circuits → behavior → self‑report → clinical phenotype. Culture‑bound syndromes appear in DSM‑IV appendix; they are not fully described in DSM‑5‑TR. --- 🔄 Key Processes Diagnostic workflow (DSM‑5‑TR/ICD‑11): Gather comprehensive history → identify distress & impairment → match symptom checklist to criteria → assign severity/specifier → code. Transition from categorical to hybrid (personality disorders): Use trait dimensional assessment (e.g., PID‑5) → determine if traits meet threshold for a categorical PD → assign specifier. RDoC research cycle: Define a construct (e.g., “working memory”) → select units of analysis (fMRI, genetics, behavior) → collect multimodal data → map onto clinical phenotypes. --- 🔍 Key Comparisons ICD‑11 vs DSM‑5‑TR Coding: ICD‑11 uses alphanumeric codes; DSM‑5‑TR uses numeric DSM‑5‑TR codes. Cultural lens: ICD‑11 explicitly encourages cultural context; DSM‑5‑TR includes cultural formulation interview but is US‑centric. Structure: ICD‑11 groups disorders into chapters; DSM‑5‑TR lists all categories in a single volume. Categorical vs Dimensional Cut‑off: Categorical needs a threshold (e.g., ≥5 of 9 depressive symptoms); Dimensional records continuous scores regardless of threshold. Utility: Categorical → easy billing, communication; Dimensional → better predicts functional outcome, captures comorbidity. DSM‑5‑TR vs RDoC Purpose: DSM = clinical diagnosis & insurance; RDoC = research framework. Basis: DSM = symptom checklists; RDoC = neurobehavioral domains across genes‑circuits‑behavior. --- ⚠️ Common Misunderstandings “Distress alone = disorder.” Distress must be paired with functional impairment. “Any cultural practice is a disorder.” Culturally sanctioned behaviors are excluded from diagnosis. “DSM‑5‑TR eliminates all sub‑threshold cases.” Specifiers (e.g., “subclinical”) allow clinicians to note milder presentations. “RDoC will replace DSM soon.” RDoC is a research tool; it does not dictate clinical coding. --- 🧠 Mental Models / Intuition “Fuzzy prototype” – Think of mental disorder as a cloud: core features (distress, impairment) form the dense center; peripheral symptoms may vary across cultures and individuals. Spectrum analogy – Visualize mood disorders as a color gradient from mild dysphoria to severe mania; the label changes only at clinically relevant cut‑offs. Dimensional “thermometer” – Rate each symptom on a 0‑3 scale; the total height predicts impairment more reliably than a simple “yes/no” label. --- 🚩 Exceptions & Edge Cases Culture‑bound syndromes may mimic DSM categories but lack formal criteria; clinicians must document cultural context rather than force a DSM label. Social deviance without dysfunction (e.g., unconventional religious practices) is not a mental disorder. Neurodevelopmental vs Neurological – Autism spectrum (neurodevelopmental) is classified in DSM/ICD, whereas cerebral palsy (neurological) is not, even though brain dysfunction underlies both. Binge‑eating disorder – Recognized as a discrete disorder in DSM‑5‑TR, but ICD‑11 still groups it under eating disorders, unspecified (as of the current release). --- 📍 When to Use Which Clinical diagnosis / billing → DSM‑5‑TR (US) or ICD‑11 (international). Cross‑cultural case formulation → Prefer ICD‑11 because of its built‑in cultural sensitivity. Research on neurobiology or genetics → Use RDoC domains to align measures across units of analysis. When a patient sits on a symptom border → Apply dimensional rating first; if the score crosses the categorical threshold, assign the DSM/ICD label. --- 👀 Patterns to Recognize “Missing impairment” – many test stems list symptoms but omit functional decline; without impairment, no diagnosis. “Cultural exception clause” – look for wording like “behaviour consistent with cultural or religious practices” → exclude. “Specifiers indicate severity” – presence of “with mixed features,” “with anxious distress,” etc., signals a need to add a severity modifier. “Shift from subtypes to spectra” – e.g., schizophrenia subtypes gone → expect questions about overall psychosis spectrum rather than “paranoid type.” --- 🗂️ Exam Traps Distractor: “Distress alone is sufficient for diagnosis.” – Wrong; impairment is also required. Distractor: “RDoC replaces DSM for clinical work.” – Incorrect; RDoC is research‑only. Distractor: “ICD‑11 does not consider culture.” – Opposite; it explicitly encourages cultural context. Distractor: “All DSM‑5‑TR categories have direct ICD‑11 equivalents.” – Generally true, but coding structures differ and some newer DSM‑5‑TR additions (e.g., binge‑eating disorder) may be grouped differently in ICD‑11. Distractor: “Five‑axis system still used in DSM‑5‑TR.” – Eliminated after DSM‑IV. ---