Reference
Glossary
Every term you will meet on a clinic website or an intake form, defined in plain language and nothing else.
A
Anaesthetic dose
Also: Surgical dose
The dose used to render a person unconscious for surgery, several times higher than the subanaesthetic dose used for mood indications.
B
BDNF
Also: Brain-derived neurotrophic factor
Brain-derived neurotrophic factor, a protein involved in the growth and survival of neurons. A surge in BDNF is part of the proposed mechanism by which ketamine may produce antidepressant effects.
Bioavailability
The proportion of an administered dose that reaches the bloodstream unchanged. It differs sharply between intravenous, intramuscular and sublingual routes, which is why the same milligram figure means different things.
D
Dissociation
A sense of detachment from the body, surroundings or the passage of time. It is the effect people most commonly ask about, typically peaks partway through an infusion, and usually resolves within half an hour of the session ending.
E
Esketamine
Also: Spravato
The S-enantiomer of ketamine, marketed as Spravato. It holds FDA approval for treatment-resistant depression in adults and is restricted to certified centres under a REMS programme.
G
Glutamate system
The brain's principal excitatory neurotransmitter system. Ketamine acts on it, which is what distinguishes its mechanism from conventional antidepressants that target monoamines.
I
Induction course
Also: Loading phase
The initial series of sessions, conventionally six delivered over two to three weeks. The figure comes from early trial protocols rather than comparative research.
Integration
The structured work of making sense of what a session surfaced, usually delivered as therapy in the days afterwards. Programmes differ enormously in how seriously they take it.
M
Maintenance
Also: Booster sessions
Ongoing sessions after the induction course, commonly every two to six weeks. This is the part that determines the real annual cost of treatment.
N
NMDA receptor
Also: N-methyl-D-aspartate receptor
N-methyl-D-aspartate receptor, a glutamate receptor at which ketamine acts as an antagonist. This is the primary molecular target underlying its effects.
Neuroplasticity
The brain's capacity to form and reorganise connections. The hypothesis that ketamine opens a temporary window of heightened plasticity is the reason integration therapy is thought to matter.
O
Off-label
The use of an approved drug for an indication it was not approved for. It is legal and routine across medicine. Generic ketamine used for depression is off-label; esketamine for treatment-resistant depression is not.
R
REMS
Also: Risk Evaluation and Mitigation Strategy
Risk Evaluation and Mitigation Strategy, an FDA safety programme. Esketamine's REMS restricts administration to certified centres and requires at least two hours of post-dose observation.
S
Schedule III
A US controlled substance classification indicating recognised potential for misuse and dependence. Ketamine sits here, which shapes how legitimate programmes are structured.
Subanaesthetic dose
Also: Low-dose ketamine
The low dose used for mood indications, typically near 0.5 mg/kg over about forty minutes. The person remains awake, breathing independently and able to communicate.
T
Titration
Adjusting a dose between sessions according to response and tolerability, rather than running a fixed protocol regardless of what the previous session produced.
Treatment-resistant depression
Also: TRD
Depression that has not responded adequately to at least two antidepressant trials at appropriate doses and durations. The term has a specific meaning and only applies after those trials.