Classification & Assessment in Psychiatry · Paper A
ICD-11 and DSM-5-TR classification: structure, editions and history
ICD-11 is the World Health Organization's latest diagnostic manual. This concept is about what it changed compared with the older ICD-10, the new diagnoses and the reorganised categories that examiners like to test. A question describing a personality disorder rated by severity rather than a named subtype signals ICD-11 by that phrasing alone. Recognising the newer terminology itself is often the fastest route to the right answer.
New diagnoses include prolonged grief disorder, complex PTSDPost-traumatic stress disorder, a condition triggered by experiencing or witnessing a traumatic event.Read more → (post-traumatic stress disorder, a severe long-term reaction to trauma), gaming disorder and body integrity dysphoria. Personality disorder is now rated by SEVERITY (mild, moderate or severe), with optional trait descriptions, replacing the old named subtypes. For schizophreniaA long-term mental illness involving episodes of psychosis such as hallucinations and delusions.Read more →, characteristic symptoms need last only ONE MONTH (DSM-5 requires six months including milder phases); the classic subtypes are dropped and the old Schneiderian 'first-rank' symptoms are de-emphasised. A stem that names an emphasis on Schneiderian first-rank symptoms to support a schizophrenia diagnosis is leaning on older thinking. A one-month schizophrenia duration or a severity-rated personality disorder in a stem is naming ICD-11, not DSM-5 (e.g. a 5-week psychosis history meets ICD-11's threshold but falls short of DSM-5's six months).
ICD-11 is the World Health Organization's current diagnostic manual, and it made real structural changes compared with ICD-10, not just cosmetic renaming. Exam writers like this territory because a stem's precise wording (a duration, a rating scale, a diagnosis that did not exist before) can only be answered correctly if the candidate knows what specifically changed, rather than relying on general psychiatric knowledge.
ICD-11 (the 11th revision of the International Classification of Diseases) is the WHO's current global diagnostic manual, distinct from DSM-5 (the American Psychiatric Association's manual), which uses different criteria for some of the same conditions. A CATEGORICAL system classifies a disorder into one of several fixed named subtypes. A DIMENSIONAL or SEVERITY-based system instead rates how mild, moderate or severe a single underlying condition is, optionally alongside descriptive trait domains, rather than sorting the patient into a discrete subtype box.
A common trap is assuming ICD-11 simply renamed ICD-10 categories. Suppose a stem describes a patient whose personality disorder is rated as "moderate" with prominent negative-affectivity traits, rather than being labelled with a named subtype such as "anankastic" or "histrionic": that severity-and-trait phrasing is not a paraphrase of an old subtype, it is the entirely new ICD-11 dimensional model replacing the old categorical one.
WHO diagnostic manuals are periodically revised as evidence and clinical utility considerations evolve; ICD-11 reflects a broader shift in psychiatric classification toward measuring severity along a spectrum rather than forcing patients into rigid, sometimes overlapping subtype categories that clinicians in practice often found hard to apply consistently. This same philosophy shows up across several ICD-11 changes, not only in personality disorder.
Personality disorder is now rated by severity (mild, moderate or severe), with optional trait-domain descriptions, replacing the old named subtypes such as paranoid or histrionic personality disorder. For , characteristic symptoms need only last one month, compared with DSM-5's six-month requirement including and residual phases; the classic subtypes (paranoid, hebephrenic, catatonic and so on) are dropped, and Schneiderian first-rank symptoms are de-emphasised as diagnostically decisive. New diagnoses appear that did not exist in ICD-10: prolonged grief disorder, complex (post-traumatic stress disorder, a severe and long-lasting reaction to trauma, involving disturbances of affect, self-concept and relationships in addition to core PTSD symptoms), gaming disorder, and body integrity dysphoria. A new category, bodily distress disorder, now covers territory that ICD-10 called neurasthenia. Disorders can now, in principle, be diagnosed at any age, rather than being artificially restricted to adult-onset presentations.
Do not confuse ICD-11's one-month threshold with DSM-5's six-month requirement: a stem describing a five-week history of psychotic symptoms meets the ICD-11 threshold even though it would fall short of DSM-5 criteria, and the correct answer depends entirely on which manual the stem is using. Do not confuse complex , a distinct ICD-11 diagnosis with added disturbances of self and relationships, with ordinary PTSD alone.
Diagnosis under ICD-11 for personality disorder proceeds by first establishing that a personality disorder is present at all, then rating its severity and, optionally, describing prominent trait domains, rather than searching for the best-fitting subtype label. For , diagnosis requires the characteristic symptoms for at least one month, without requiring the longer -plus-residual timeline DSM-5 demands.
While ICD-11 itself is a classification system rather than a treatment guideline, the diagnostic category assigned still drives which management pathway a service follows: a complex diagnosis, for instance, may prompt a different, longer-phase trauma-focused therapy pathway than straightforward PTSD, and services increasingly reference ICD-11 terminology in referral criteria and NICE-aligned care pathways.
Severity-rated personality disorder in a stem signals ICD-11, not DSM-5. A one-month duration signals ICD-11. Complex , gaming disorder, prolonged grief disorder and body integrity dysphoria are all new ICD-11 diagnoses absent from ICD-10. When a vignette turns on a recent diagnostic change or an unfamiliar duration threshold, ICD-11 is usually the reason.
ICD-11's headline changes are new diagnoses (complex , prolonged grief disorder, gaming disorder, body integrity dysphoria, bodily distress disorder) and a broader shift from fixed categorical subtypes to severity-and-trait dimensional ratings, most visibly in personality disorder, alongside a shortened one-month duration threshold for ; recognising this newer terminology and these shortened thresholds is usually the fastest way to identify that a stem is testing ICD-11 rather than DSM-5.