Category · F10-F19 block
F11 — Mental and behavioural disorders due to use of opioids
Terminology note: "Opioids" covers both illicit substances (e.g. heroin) and prescribed or diverted medications (e.g. morphine, codeine, tramadol) used outside their intended pattern. The classification does not distinguish by legal status of the substance, only by the clinical state present.
What is this category?
F11 applies the block's shared dependence-syndrome and withdrawal-state framework to opioids. Its most important teaching contrast is with F10 and F13: opioid withdrawal is intensely distressing but, unlike alcohol or sedative withdrawal, is not typically medically dangerous on its own — a distinction learners frequently get backwards by assuming all withdrawal is equally urgent.
Core diagnostic concept
As with every category in this block, the central question is whether the six dependence-syndrome features — desire/compulsion, control difficulty, tolerance, withdrawal, neglect of alternatives, continued use despite harm — cluster together, rather than whether opioid use is occurring at all (for example, a person can use prescribed opioids appropriately for pain without meeting these criteria). The second key question specific to F11 is severity triage: opioid withdrawal, however severe subjectively, is managed very differently from alcohol or sedative withdrawal precisely because it lacks the seizure/delirium risk those carry.
Key diagnostic features
- Strong desire or compulsion to use
- A subjective pull toward using opioids, often intensifying as the next dose becomes due.
- Difficulty controlling use
- Difficulty limiting dose, frequency, or duration of use once started, including using more than intended.
- Tolerance
- Requiring escalating doses to achieve the same effect, a hallmark of sustained opioid use.
- Withdrawal state
- A distinctive syndrome (muscle aches, gooseflesh, yawning, watery eyes, diarrhoea, dysphoria, intense craving) on stopping or reducing use — highly distressing subjectively but not typically medically dangerous by itself.
- Neglect of alternative interests
- Increasing time obtaining, using, and recovering from opioids at the expense of other responsibilities and pleasures.
- Continued use despite harm
- Persisting despite awareness of physical, psychological, social, occupational or legal harm.
How to weigh evidence
These learning labels are teaching aids, not official ICD-10 terminology (see Sources and Method).
- supports Escalating self-administered doses of a prescribed opioid beyond what was prescribed, intense early-morning craving, and withdrawal symptoms relieved specifically by using again.
- consistent not decisive The person is prescribed a strong opioid for chronic pain. Appropriate, supervised medical use for pain does not by itself indicate dependence.
- raises alternative Use only during a brief prescribed post-surgical course, stopped without difficulty once healing occurred, with no craving reported afterward.
- contradicts or weakens No tolerance increase over months of steady prescribed dosing, and no difficulty stopping when the course ended.
- missing and necessary to ask Whether the person has ever tried to stop and, if so, what symptoms (if any) followed, and how severe/dangerous they were.
Diagnostic boundary
F11 is distinguished from appropriate medical opioid use by the presence of the dependence cluster rather than supervised, indicated treatment; from F10/F13 by opioid withdrawal's characteristic symptom pattern and markedly lower acute medical danger; and its psychotic-disorder subtype from an independent psychiatric illness by temporal relationship to use.
Full comparisons:
Duration and course
Minimum duration: As with F10, dependence syndrome is typically established by three or more criteria present together within the past year.
Course: Short-acting opioid withdrawal (e.g. heroin) typically begins 6-12 hours after last use, peaks around 1-3 days, and substantially resolves within about a week; longer-acting opioids have a delayed, more protracted course.
Included presentations
- A pattern meeting three or more dependence-syndrome criteria for opioid use within the past year.
- A withdrawal state with the characteristic opioid symptom pattern, temporally linked to reducing or stopping sustained use.
- Harmful use of an opioid causing demonstrable harm without the fuller dependence cluster.
Exclusions and distinguishing presentations
| If this is true instead… | Consider | Why |
|---|---|---|
| A comparably severe withdrawal course carrying seizure or delirium risk | F10 | Unlike alcohol and sedative withdrawal, opioid withdrawal is not typically medically dangerous, even though it is highly distressing — a key severity-triage distinction. |
| Persisting psychotic symptoms better explained by an independent psychiatric illness than by opioid use | independent psychiatric illness capsule | Psychotic phenomena during opioid use are less classically taught than with stimulants or cannabinoids, so an independent illness should be actively considered rather than assumed away. |
Four-character subtypes (orientation)
A learner should not assume every opioid withdrawal case requires the same urgency as alcohol withdrawal from symptom severity alone. These subtypes beyond F11.2 and F11.3 are taught here for orientation only and are not separately assessed in this pilot.
- F11.0 — Acute intoxication
- Transient euphoria/sedation, pupil constriction, drowsiness following use. (taught for orientation only, not separately assessed in this pilot)
- F11.1 — Harmful use
- A pattern causing demonstrable harm without the fuller dependence cluster. (taught for orientation only, not separately assessed in this pilot)
- F11.2 — Dependence syndrome
- Three or more of the six dependence criteria present together within the past year. (in_depth)
- F11.3 — Withdrawal state
- A characteristic, highly distressing but not typically medically dangerous symptom cluster on stopping or reducing use. (in_depth)
- F11.4 — Withdrawal state with delirium
- Rare with opioids alone; more relevant when combined with other substances. (taught for orientation only, not separately assessed in this pilot)
- F11.5 — Psychotic disorder
- Psychotic phenomena occurring during or immediately after opioid use. (taught for orientation only, not separately assessed in this pilot)
- F11.6 — Amnesic syndrome
- Chronic memory impairment associated with sustained opioid use — less classically described than with alcohol. (taught for orientation only, not separately assessed in this pilot)
- F11.7 — Residual and late-onset psychotic disorder
- Opioid-related changes persisting beyond the period of direct action. (taught for orientation only, not separately assessed in this pilot)
- F11.8 — Other mental and behavioural disorders
- An opioid-related presentation not fitting the other listed states. (taught for orientation only, not separately assessed in this pilot)
- F11.9 — Unspecified mental and behavioural disorder
- An opioid-related disturbance identified but without enough information to classify further. (taught for orientation only, not separately assessed in this pilot)
External causes to check first
Categories in this block require that the disturbance is not better explained by another external cause listed below. These short capsules are reminders, not full teaching modules.
External cause capsule — Considering an independent psychiatric illness
A reminder that a psychotic (or other psychiatric) presentation occurring alongside substance use should not automatically be assumed substance-induced — an independent illness should be actively considered when the evidence points that way, before settling for an F1x subtype as the final answer.
What to check:
- Persistence: has the presentation continued essentially unchanged well beyond that substance's expected substance-induced resolution window despite confirmed abstinence, rather than gradually resolving?
- Trajectory: is the picture static or worsening despite abstinence, rather than the gradual improvement typically expected of a resolving substance-induced disorder?
- History: is there a personal or family history of psychotic or other psychiatric illness that would raise the prior likelihood of an independent illness?
- Onset: did any psychiatric symptoms clearly predate the substance use in question, which would argue against a purely substance-induced explanation?
A full differential workup distinguishing a resolving substance-induced disorder from an emerging independent illness, which requires assessment beyond what a single vignette can establish — the honest classification-reasoning answer is often "consider an independent illness" rather than a fully certain diagnosis in either direction.
Common learner errors
Worked example — appropriate medical use versus dependence syndrome
A 55-year-old has been prescribed a strong opioid for severe chronic back pain for the past two years. Over that time the effective dose has been increased twice by her physician as pain control lessened. She takes the medication as prescribed, has never taken extra without approval, and manages her work and family life without disruption. She mentions mild discomfort if a dose is delayed slightly.
- Step 1 — Check for control difficulty: she takes the medication exactly as prescribed, with no reported difficulty limiting or controlling use.
- Step 2 — Check for neglect of alternative interests: work and family functioning are both intact, with no evidence of priorities shifting toward obtaining or using the medication.
- Step 3 — Note tolerance and mild withdrawal-type discomfort: dose increases and mild discomfort with delay are expected physiological accompaniments of sustained opioid treatment, not evidence of dependence syndrome by themselves.
- Step 4 — Weigh the overall cluster: only tolerance and a mild physiological dependence are present; the compulsion, control-difficulty, and continued-use-despite-harm criteria are absent.
- Conclusion — This is best understood as appropriate, supervised medical opioid use, not F11 dependence syndrome, because physiological tolerance and mild withdrawal-type phenomena alone do not meet the fuller dependence-syndrome cluster.
Interactive practice
- Type A Escalating use of a pain medication Recognition / application · Foundation
- Type B Distressing, but how dangerous? Boundary / differential · Boundary
- Type C Pain, prescriptions, and an unclear pattern Insufficient information · Developing
Retrieval prompts
Try answering each of these from memory before revealing where to check. Nothing you think or type here is sent or saved anywhere.
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Without looking back at the page, state why opioid withdrawal is generally considered less medically dangerous than alcohol withdrawal.
Reveal answer location
Check Duration and course, Diagnostic boundary, or the rapid revision card below — the cue you need is one of those, in this category's own already-authored wording.
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Name one feature that would make you consider appropriate medical use rather than dependence syndrome in an opioid case.
Reveal answer location
Check Duration and course, Diagnostic boundary, or the rapid revision card below — the cue you need is one of those, in this category's own already-authored wording.
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Explain in one sentence why tolerance and a mild withdrawal-type symptom alone are not enough to establish dependence.
Reveal answer location
Check Duration and course, Diagnostic boundary, or the rapid revision card below — the cue you need is one of those, in this category's own already-authored wording.
These self-checks are a personal study aid only, visible to you on this page for this visit — they are not stored and do not affect your mastery dimensions.
Rapid revision card
F11: The same six-criteria dependence-syndrome cluster applied to opioids, with a key added distinction: opioid withdrawal is intensely distressing but not typically medically dangerous, unlike alcohol or sedative withdrawal.
Decisive boundary cues:
- Control difficulty plus continued use despite harm -> weighs toward F11.2 dependence over appropriate medical use.
- Tolerance and mild withdrawal-type discomfort alone, under supervised appropriate treatment -> does not by itself establish dependence.
- Severity of subjective distress in withdrawal does not equal medical danger -> unlike F10/F13, opioid withdrawal is not typically life-threatening.
Duration/course: Short-acting opioid withdrawal typically begins 6-12 hours after last use and substantially resolves within about a week.
Nearest alternatives: F13, F10
Common mistake: Assuming any opioid withdrawal is as medically dangerous as alcohol or sedative withdrawal.
Retrieval prompt: What single question would you ask first to check whether this is appropriate medical use rather than dependence?
(or use your browser's print function) Open full-page printable revision view →
Related glossary terms
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Dependence syndrome
A cluster of behavioural, cognitive, and physiological phenomena that develop after repeated substance use, in which use of that substance takes on a much higher priority than other behaviours that once had greater value. Classically established when three or more of six criteria (strong desire/compulsion, difficulty controlling use, tolerance, a physiological withdrawal state, progressive neglect of alternative interests, and continued use despite clear harm) have been present together within the past year.
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Tolerance
A state in which increasing amounts of a substance are needed to achieve the effects originally produced by a lower amount, or in which continued use of the same amount produces a markedly diminished effect. One of the six criteria contributing to a dependence-syndrome classification.
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Withdrawal state
A group of symptoms, of variable severity and clustering, occurring on absolute or relative withdrawal of a substance after repeated, and usually prolonged and/or high-dose, use of that substance. Onset, timing, and medical danger vary considerably by substance.
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Craving
A strong subjective desire or compulsion to use a substance. One of the six criteria contributing to a dependence-syndrome classification, and often prominent during withdrawal as well.
Source basis
WHO ICD-10 international classification structure and code/title (ICD-10 Browser, 2019 English release).
Original educational synthesis, informed by general published clinical-education understanding of ICD-10 F11 and the general dependence-syndrome criteria; no verbatim CDDG or DCR text is reproduced. See Sources and Method for the full policy.
Last reviewed: 2026-09-15. Full policy: Sources and Method.
Educational resource only. This page and its cases teach ICD-10 classification reasoning using fictional scenarios. It does not diagnose real people and should not be used to assess yourself or anyone else. If you are worried about your own or someone else's opioid or other drug use, please speak with a qualified health professional.