F15 — Mental and behavioural disorders due to use of other stimulants, including caffeine

What is this category?

F15's most important teaching point is restraint: because caffeine is included here, this category is the clearest test of whether a learner over-applies the dependence-syndrome framework to any regular substance use rather than checking the actual criteria. Amphetamine-type stimulants otherwise parallel cocaine (F14) closely in intoxication and psychotic-disorder phenomena.

Core diagnostic concept

For amphetamine-type stimulants, the classification approach mirrors F14 closely: distinguish transient intoxication phenomena from a more sustained substance-induced psychotic disorder by timing and persistence. For caffeine specifically, the central question is different and more basic: does a genuine six-criteria dependence cluster exist, or is this simply regular, unproblematic daily use that happens to involve a psychoactive substance?

Key diagnostic features

Acute intoxication phenomena (amphetamine-type)

Euphoria, increased energy, agitation, and sometimes suspiciousness during and shortly after use, closely paralleling cocaine intoxication.

Caffeine intoxication

Restlessness, nervousness, insomnia, and rapid heart rate following notably excessive intake — a real, if rarely clinically significant, ICD-10 state distinct from ordinary caffeine consumption.

Dependence syndrome

The same six-criteria cluster applied to whichever stimulant is used; for caffeine, this is uncommon and requires genuine evidence of control difficulty, tolerance, and continued use despite harm — not simply drinking coffee every morning.

Psychotic disorder (amphetamine-type)

A sustained psychotic picture, closely resembling cocaine-induced psychosis, temporally linked to heavy amphetamine-type stimulant use.

Withdrawal state

For amphetamine-type stimulants, a 'crash' similar to cocaine's; for caffeine, headache, fatigue, and irritability on abruptly stopping regular substantial intake.

How to weigh evidence

These learning labels are teaching aids, not official ICD-10 terminology (see Sources and Method).

• supports Escalating use of an amphetamine-type stimulant with agitation, paranoia persisting for over a week despite verified abstinence, and clear difficulty controlling use.
• consistent not decisive The person drinks three cups of coffee every morning and feels tired without it. Regular caffeine use with mild withdrawal-type tiredness alone does not establish dependence syndrome.
• raises alternative Headache and irritability only on the specific days coffee is skipped, with no difficulty controlling ordinary intake and no harm reported.
• contradicts or weakens No control difficulty, no escalating use, and no harm from what remains an unremarkable daily caffeine habit.
• missing and necessary to ask Whether there is any difficulty controlling intake or any harm from the substance use, rather than simply how often it occurs.

Duration and course

Minimum duration: Dependence syndrome, as elsewhere in this block, is typically established by three or more criteria present together within the past year — genuinely uncommon for caffeine.

Course: Amphetamine-type stimulant intoxication and psychotic-disorder timing closely parallel cocaine's; caffeine intoxication and withdrawal are both typically brief, resolving within a day or so.

Included presentations

• Transient amphetamine-type stimulant intoxication with euphoria and agitation, resolving as expected.
• A pattern meeting three or more dependence-syndrome criteria for any stimulant covered by this category, including the uncommon case of genuine caffeine dependence.
• Caffeine intoxication following notably excessive intake.

Exclusions and distinguishing presentations

Four-character subtypes (orientation)

A learner should not classify ordinary daily caffeine use as dependence syndrome or intoxication without genuine evidence of the full criteria or notably excessive intake respectively. Subtypes beyond F15.0 and F15.2 are taught here for orientation only and are not separately assessed in this pilot.

F15.0 — Acute intoxication

Euphoria and agitation (amphetamine-type) or restlessness and rapid heart rate (caffeine) during and shortly after use. (in_depth)

F15.1 — Harmful use

A pattern causing demonstrable harm without the fuller dependence cluster. (taught for orientation only, not separately assessed in this pilot)

F15.2 — Dependence syndrome

Three or more of the six dependence criteria present together within the past year — genuinely uncommon for caffeine specifically. (in_depth)

F15.3 — Withdrawal state

A post-use 'crash' (amphetamine-type) or headache/fatigue/irritability (caffeine) on stopping regular substantial intake. (taught for orientation only, not separately assessed in this pilot)

F15.4 — Withdrawal state with delirium

Rare with this category's substances. (taught for orientation only, not separately assessed in this pilot)

F15.5 — Psychotic disorder

A sustained psychotic picture temporally linked to heavy amphetamine-type stimulant use, closely paralleling cocaine. (taught for orientation only, not separately assessed in this pilot)

F15.6 — Amnesic syndrome

Chronic memory impairment associated with sustained use — rare with this category's substances. (taught for orientation only, not separately assessed in this pilot)

F15.7 — Residual and late-onset psychotic disorder

Stimulant-related changes persisting beyond the period of direct action. (taught for orientation only, not separately assessed in this pilot)

F15.8 — Other mental and behavioural disorders

A stimulant-related presentation not fitting the other listed states. (taught for orientation only, not separately assessed in this pilot)

F15.9 — Unspecified mental and behavioural disorder

A stimulant-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.

Common learner errors

• Common mistake: Treating any regular use of a psychoactive substance as automatic dependence

Worked example — ordinary caffeine use versus dependence syndrome

A 33-year-old drinks two cups of coffee every morning, has done so for years, and reports a mild headache on the rare day she skips it, which resolves once she has a cup later that day. She has never tried to cut down, has no difficulty controlling her intake, and reports no harm of any kind from her coffee habit. She specifically asks whether this means she is "dependent on caffeine."

1. Step 1 — Check for control difficulty: she reports no difficulty controlling her intake and has never needed or wanted to cut down.
2. Step 2 — Check for tolerance: no mention of escalating amounts needed for the same effect over the years.
3. Step 3 — Check for harm: she reports no harm of any kind — physical, social, or occupational — from her coffee habit.
4. Step 4 — Weigh the mild withdrawal-type headache alone: an occasional mild headache resolved by a cup of coffee is a minor physiological accompaniment, not evidence of the fuller dependence cluster by itself.
5. Conclusion — This is best understood as ordinary, unproblematic caffeine use, not dependence syndrome (F15.2), because only a single, mild criterion is present and none of the others — control difficulty, tolerance, neglect of alternatives, or harm despite continued use — are met.

Interactive practice

• Type A Just her morning coffee? Recognition / application · Foundation
• Type B Which stimulant, and does it matter? Boundary / differential · Boundary

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.

1. Without looking back at the page, state why caffeine's inclusion in this category is a deliberate teaching point rather than a claim that coffee drinking is a disorder.

   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.

   I recalled this I need to review this

2. Name the feature that most distinguishes ordinary regular caffeine use from caffeine dependence syndrome.

   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.

   I recalled this I need to review this

3. Explain in one sentence how amphetamine-type stimulant intoxication and psychosis parallel cocaine's.

   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.

   I recalled this I need to review this

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.

Related glossary terms

• 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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