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Research draft

antidepressant

vr.tr.antidepressant · PHY.OBJ

Enable an AI agent to recognise an antidepressant medicinal product, assess its documented condition and use constraints, and identify actions requiring clinical or pharmaceutical authority.

Thing Registry Physical world and living systems

Research draft, second pass

A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.

Researched by: Codex + Grok

Purpose and description

Enable an AI agent to recognise an antidepressant medicinal product, assess its documented condition and use constraints, and identify actions requiring clinical or pharmaceutical authority.

A prescription psychotropic medicine whose primary licensed indication is the treatment of depressive disorders, acting mainly by modulating monoamine neurotransmission (serotonin, noradrenaline, and/or dopamine) or related glutamatergic/melatonergic pathways.

It can be Match a label or pack to an antidepressant product record and flag uncertain identity.; Compare ingredient, strength, route and release characteristics while identifying equivalence claims that require authoritative confirmation.; Retrieve applicable product instructions and surface unresolved safety checks for an authorised professional.; Link a pack to an existing prescription or treatment plan and flag mismatches without generating a new regimen.; Record storage concerns, expiry or recall matches and route the pack for quarantine or disposition review.; Document suspected adverse effects or treatment-change concerns and route them to the responsible clinical workflow..

Distinguishing features

Require an identified medicinal product and an attributable basis for calling it an antidepressant; a mood-related marketing claim alone does not establish membership.

Separate antidepressant product identity from the condition for which someone receives it; classification and the indication for a particular use must be recorded independently.

Distinguish the finished medicinal product from its active substance by recording formulation, strength, route and release characteristics.

Distinguish an antidepressant from another medicine used alongside it by requiring classification evidence for that product itself.

Distinguish a physical product or pack from a prescription or treatment plan: instructions referring to a medicine are not the medicine.

Scope

+ Evidence supporting classification of a medicinal product as an antidepressant

+ Active ingredient composition, strength, dosage form, route and release characteristics

+ Product-specific authorised uses and instructions, with jurisdiction and source dates

+ Documented safety constraints relevant to evaluating a proposed use

+ Condition, traceability and disposition of a particular pack or batch

- Diagnosis and longitudinal assessment of depression or other conditions

- Patient medical history, preferences and clinical risk assessment

- Individual prescribing decisions, dose schedules and treatment-change plans

- Molecular structure, synthesis and pharmacology of active substances as independent entities

- Psychotherapy delivery and organisation of mental health services

Characteristics

Antidepressant classification basis
Source-attributed classification; confirmed, disputed or unresolved Establishes membership without relying on product names or the recipient's diagnosis.
Active ingredient composition
Links to each identified active substance, preserving the labelled chemical form Supports ingredient matching and detection of overlapping products.
Labelled strength
Labelled mass per dosage unit or mass per volume, with ingredient and expression basis Prevents confusion between presentations and between concentration and administered dose.
Administration presentation
Source-attributed dosage form, administration route and release designation Determines which handling and administration instructions must be consulted.
Authorisation context
Product authorisation record linked to jurisdiction, status and effective date Keeps recognised uses and restrictions tied to the applicable product and jurisdiction.
Applicable safety information
Versioned product information and safety notices Provides an attributable basis for reviewing proposed use and escalation requirements.
Pack usability
Unassessed, no recorded defect, review required, quarantined or unsuitable; with evidence Separates observed physical suitability from clinical suitability for a person.
Batch and expiry identity
Manufacturer or supplier identifiers, batch identifier and labelled expiry Supports recall matching and assessment of whether the pack remains usable.

Also called

monoamine oxidase inhibitorMelatonin receptor agonisttetracyclic antidepressantserotonin–norepinephrine reuptake inhibitorselective serotonin reuptake inhibitorAtypical antidepressantnoradrenergic and specific serotonergic antidepressantantidepressants in Japansecond-generation antidepressive agentsadrenergic uptake inhibitorstricyclic antidepressant

Where this came from

wikidata · CC0 1.0

Also registered as vr.tr.antidepressant

Drafted structure

Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 18 findings · 32 questions.

Antidepressant identity Establishes which medicinal product is represented and why it belongs in this registry entry.

An agent must distinguish product classification from mood-related claims, active-substance identity and the reason a person receives treatment.

Classification evidence

Records the attributable basis and boundaries of antidepressant membership.

Membership basis

Record the classification claim, its source and any disagreement without treating the registry name as proof.

  1. Which authoritative record identifies this product or its active ingredient as an antidepressant? provenance
  2. How is membership distinguished from a mood-support claim or use as an accompanying medicine? boundary

Product resolution

Separates the medicinal product from names, substances and physical instances.

Identified product

Record enough identifying evidence to resolve the product and link a pack to it without conflating brands or formulations.

  1. Which product name, supplier, jurisdiction and product identifier resolve the medicine being represented? definition
  2. Does the available evidence identify a finished product, an active substance or only an unresolved name? boundary
Composition and presentation Captures the formulation distinctions needed to interpret an antidepressant pack and its instructions.

Ingredient names alone do not establish matching strength, administration characteristics or permissible handling.

Ingredient and strength

Records what each dosage unit or volume contains using the label's expression basis.

Labelled composition

Preserve each active ingredient, its labelled form and its stated quantity rather than silently normalising potentially different expressions.

  1. Which active ingredients and chemical forms are stated in the product information? definition
  2. What strength or concentration is stated for each ingredient, in which units and on what expression basis? measurement

Release and administration

Links dosage form, route and release designation to product-specific handling instructions.

Presentation constraints

Record administration characteristics and sourced permissions for altering a dosage form or comparing alternative presentations.

  1. Which dosage form, route and release designation identify this presentation? definition
  2. What do the applicable instructions permit or prohibit regarding splitting, crushing, opening or preparing this presentation? action
  3. What authoritative evidence is required before treating another presentation as interchangeable? boundary
Therapeutic use context Connects the antidepressant product to documented uses and an externally governed treatment plan.

Product classification, authorised indications and the purpose of an individual prescription are distinct facts.

Authorised use

Records the jurisdiction-specific scope of the product's authorisation.

Indication and population boundaries

Represent labelled indications and population limits as dated source claims rather than universal permissions.

  1. Which indications and population boundaries appear in the applicable product authorisation? boundary
  2. Which jurisdiction, document version and effective date support those boundaries? provenance

Treatment plan link

Relates the product to an existing clinical instruction without owning prescribing decisions.

Intended use match

Record whether the identified presentation matches the referenced prescription and keep the clinical purpose in the linked treatment plan.

  1. Which authorised prescription or treatment-plan record specifies the intended product and presentation? provenance
  2. Which identity, strength, route or release mismatches require resolution before the proposed action proceeds? action
Safety and treatment changes Makes antidepressant safety information and treatment-transition constraints available for professional review.

An agent needs to recognise unresolved contraindication, interaction, monitoring and treatment-change questions without deciding a person's regimen.

Use safety review

Links product-specific warnings to the external information required to assess a proposed use.

Safety check requirements

Record sourced contraindications, interactions and monitoring requirements, keeping unknown patient context distinct from a completed check.

  1. Which contraindications, interacting substances and monitoring requirements are stated for this antidepressant product? provenance
  2. Which checks require linked information about other medicines, age, pregnancy or relevant organ function? boundary
  3. What sourced escalation instructions apply to reported worsening mood, suicidal thoughts or other serious suspected reactions? action

Initiation, switching and stopping

Records where starting, changing or ending treatment requires an explicit clinical plan.

Transition instructions

Link product-specific information about treatment transitions to the responsible clinician's plan and preserve unresolved symptom attribution.

  1. Which sourced instructions address initiation, missed doses, switching, interruption or discontinuation for this product? provenance
  2. Which proposed changes require a documented clinician decision before an agent may support their execution? action
  3. How will possible discontinuation effects, adverse effects and recurrence of the treated condition be recorded without asserting an unassessed cause? boundary
Pack condition and disposition Assesses a physical antidepressant pack against its specific formulation and supply requirements.

A correctly identified antidepressant may still require withholding from use because its provenance, condition or applicable instructions are unresolved.

Traceability and condition

Connects pack evidence to product-specific expiry, storage and recall information.

Pack usability evidence

Record batch identity, expiry, observed damage and storage evidence, including any applicable limit after opening or preparation.

  1. Which product and batch identifiers connect this pack to supply records and applicable recall notices? provenance
  2. What evidence supports compliance with this presentation's expiry, storage and any after-opening or preparation limits? measurement

Permitted pack actions

Bounds physical handling and disposition using product information and applicable local authority.

Handling and disposition decision

Record the evidence and authority supporting supply, administration support, quarantine, return or disposal of the identified pack.

  1. Which applicable supply rules and professional instructions govern dispensing or administration of this antidepressant? action
  2. Which observed defects, recall matches or unresolved identity concerns require quarantine or professional review? action
  3. Which local instructions govern return or disposal of unused quantities of this product? provenance
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.

A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.

Reported evidence

Findings from the breadth pass, kept separate from the structural claims.

Kinds and varieties

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

  • Selective serotonin reuptake inhibitors (SSRIs)
  • Serotonin-noradrenaline reuptake inhibitors (SNRIs)
  • Tricyclic antidepressants (TCAs)
  • Monoamine oxidase inhibitors (MAOIs)
  • Atypical / multimodal antidepressants (e.g. mirtazapine, bupropion, vortioxetine)
  • NMDA-receptor modulators used as antidepressants (e.g. esketamine, ketamine)
  • Melatonergic antidepressants (agomelatine)
  • Herbal products used as antidepressants (St John's wort / Hypericum)
  1. Which of these kinds and varieties hold for the sense of antidepressant this model covers, and on what evidence? provenance

Identifiers and schemes

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

  • Wikidata - Q12140 - Item for the pharmacological class 'antidepressant'
  • WHO ATC - N06A* - Nervous system → psychoanaleptics → antidepressants; subgroups N06AA, N06AB, N06AF, N06AG, N06AX
  • MeSH - D000928 - Descriptor 'Antidepressive Agents'
  • RxNorm - TTY=IN or SCD under antidepressant class - US ingredient and clinical-drug codes for individual agents, not the class as a whole
  1. Which of these identifiers and schemes hold for the sense of antidepressant this model covers, and on what evidence? provenance

Standards and regulation

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

  • WHO Collaborating Centre for Drug Statistics Methodology - ATC/DDD classification N06A
  • US FDA - class labelling and boxed warning on suicidality (21 CFR drug labelling; Medication Guides)
  • EMA / national competent authorities - marketing authorisation, SmPC, and pharmacovigilance for individual products
  • NICE (England & Wales) - NG222 Depression in adults
  • Controlled-substance scheduling is generally not class-wide (most oral antidepressants are prescription-only, not scheduled; ketamine/esketamine are exceptions)
  1. Which of these standards and regulation hold for the sense of antidepressant this model covers, and on what evidence? provenance

Real-world use

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

  • Primary-care and psychiatric outpatient prescribing for major depressive disorder, often after or alongside psychological therapy
  • Licensed or off-label use for anxiety disorders, OCD, PTSD, neuropathic pain (e.g. duloxetine, amitriptyline), migraine prophylaxis, and smoking cessation (bupropion)
  • Hospital and crisis use of rapid-acting agents (IV ketamine, intranasal esketamine) for treatment-resistant depression
  • Dispensed as oral tablets/capsules for weeks to years; treatment is typically continued 6-12 months after remission of a first episode
  1. Which of these real-world use hold for the sense of antidepressant this model covers, and on what evidence? provenance

Typical measurements

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

  • Defined Daily Dose (WHO DDD) - agent-specific (e.g. sertraline 50, fluoxetine 20, amitriptyline 75, venlafaxine 100) - mg/day
  • Therapeutic plasma concentration (TDM, selected agents) - e.g. nortriptyline ~50-150; amitriptyline+nortriptyline ~80-200; venlafaxine+ODV ~100-400 - ng/mL
  • Time to clinical response - 2-6 weeks for conventional monoaminergic agents; hours to days for ketamine/esketamine - weeks (or hours for NMDA agents)
  • Treatment duration after first-episode remission - 6-12 - months
  1. Which of these typical measurements hold for the sense of antidepressant this model covers, and on what evidence? provenance

Failure modes and hazards

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

  • Inadequate response or treatment-resistant depression despite adequate dose and duration
  • Antidepressant discontinuation / withdrawal syndrome after abrupt stop or missed doses (especially short-half-life SNRIs/SSRIs)
  • Increased suicidal thinking and behaviour in people under 25, particularly early in treatment
  • Serotonin syndrome when combined with other serotonergic drugs (MAOIs, triptans, tramadol, St John's wort)
  • Hyponatraemia (SSRIs/SNRIs, especially in older adults), QTc prolongation (citalopram, some TCAs), seizures and overdose lethality (TCAs, MAOIs)
  • Manic switch in undiagnosed bipolar disorder
  • Sexual dysfunction, weight gain, bleeding risk with SSRIs (platelet serotonin)
  1. Which of these failure modes and hazards hold for the sense of antidepressant this model covers, and on what evidence? provenance

Regional variation

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

  • First-line agent choice differs: SSRIs dominate in UK/US/EU; some East Asian practice still uses more TCAs or locally marketed agents (e.g. tianeptine in parts of Europe/Asia, restricted in others)
  • St John's wort is a registered herbal medicine in Germany and some EU states, a dietary supplement in the US, and not a licensed antidepressant in the UK NHS pathway
  • Esketamine (Spravato) availability and reimbursement vary widely; IV ketamine for depression is often off-label outside specialist clinics
  • Direct-to-consumer advertising of named antidepressants is permitted in the US and New Zealand, not in most other countries
  1. Which of these regional variation hold for the sense of antidepressant this model covers, and on what evidence? provenance

Neighbouring kinds and how to tell them apart

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

  • Anxiolytic / benzodiazepine - Benzodiazepines act on GABA-A and are used for acute anxiety/insomnia; they are not antidepressants. An antidepressant may treat anxiety over weeks but does not produce immediate GABA-ergic sedation.
  • Mood stabiliser (lithium, valproate, lamotrigine) - Mood stabilisers are licensed primarily for bipolar disorder; antidepressants treat unipolar depression and can precipitate mania if bipolar illness is missed.
  • Antipsychotic - Antipsychotics target dopamine D2 (and often 5-HT2A); some (quetiapine, aripiprazole) are adjuncts in depression but the class indication is psychosis/mania, not first-line unipolar depression.
  • Stimulant / wakefulness agent - Stimulants increase catecholamines for ADHD/narcolepsy and are not licensed as antidepressants, though they may lift energy; they lack the delayed monoamine-reuptake therapeutic profile of standard antidepressants.
  • Psychotherapy / neurostimulation (CBT, ECT, rTMS) - These are interventions, not drugs; they may be first-line or alternatives and are not classified under ATC N06A.
  1. Which of these neighbouring kinds and how to tell them apart hold for the sense of antidepressant this model covers, and on what evidence? provenance

Sources

  1. ATC/DDD Index 2026: N06A Antidepressants - Official WHO anatomical-therapeutic classification of antidepressants as a drug class, with subgroups (N06AA non-selective monoamine reuptake inhibitors, N06AB SSRIs, N06AF MAOIs, N06AG MAO-A inhibitors, N06AX other antidepressants) and defined daily doses.
  2. Depression in adults: treatment and management (NG222) - UK clinical practice: first-line SSRI choice, stepped-care use, switching, duration of treatment, and distinction from psychological therapies and other medicines.
  3. Suicidality and Antidepressant Drugs - Boxed Warning / Medication Guide - US regulatory framing of the class, boxed warning on suicidality in children, adolescents and young adults, and class-wide labelling.
  4. antidepressant (Q12140) - Canonical identifier for the class as a chemical/pharmacological group, with cross-links to MeSH, ATC, and related items.

What the second pass must settle

  • Does an existing world model already own antidepressant medicinal products or a sufficiently complete parent concept, requiring a link instead of a separate publication?
  • Does the registry intend this entry to cover active substances as well as finished medicinal products, and how should the PHY.OBJ boundary be resolved?
  • Which classification authorities should establish membership, especially for combination products, disputed classifications and products authorised differently across jurisdictions?
  • Which primary product records and safety sources will be researched, versioned and maintained before this structural draft can become a supported publication?
  • Where should responsibility sit between this model and neighbouring clinical models for monitoring, treatment transitions and assessment of reported symptoms?