A-Z Medical Glossary
Plain-English definitions of treatments, conditions, credentialing, and clinical concepts covered in our reporting.
A
ABMS
American Board of Medical Specialties — the umbrella organization governing 24 specialty member boards that certify allopathic (MD) physicians in specific specialties and subspecialties.
Addiction Medicine
A medical subspecialty focused on the prevention, diagnosis, and treatment of substance use disorders. Recognized by the American Board of Preventive Medicine since 2016.
E
ECT
Electroconvulsive Therapy — a neurostimulation treatment in which a brief electrical stimulus, delivered under general anesthesia, induces a controlled seizure. Used for severe or treatment-resistant depression, mania, and catatonia.
E-E-A-T
Experience, Expertise, Authoritativeness, Trustworthiness — the framework Google's quality raters use to evaluate content credibility, especially for YMYL topics like medicine.
Esketamine
The (S)-enantiomer of ketamine, FDA-approved as the nasal spray Spravato for treatment-resistant depression and depressive symptoms in adults with major depressive disorder with acute suicidal ideation or behavior.
I
Informed Consent
The legal and ethical process by which a clinician discloses, in plain language, the diagnosis, proposed treatment, alternatives, risks, and benefits before a patient agrees to a procedure or therapy.
IV Ketamine Infusion
Slow intravenous administration of ketamine over 40-60 minutes, typically dosed at 0.5 mg/kg, used off-label for treatment-resistant depression. The most-studied ketamine-administration route in psychiatric research.
K
Ketamine
A dissociative anesthetic developed in the 1960s, now used at sub-anesthetic doses for treatment-resistant depression and other mental health conditions.
Ketamine-Assisted Therapy
A clinical protocol in which sub-anesthetic doses of ketamine are administered (IV, IM, oral, or intranasal) under medical supervision to treat depression, PTSD, anxiety, or chronic pain — typically combined with structured psychotherapy.
N
NPI
National Provider Identifier — a unique 10-digit number assigned by CMS to U.S. healthcare providers. NPIs are public and verifiable through the NPPES Registry.
NPPES
National Plan and Provider Enumeration System — the public CMS registry of NPI numbers and basic provider information for every licensed U.S. healthcare provider.
O
Off-Label Use
Prescribing an FDA-approved medication for an indication, age group, dose, or route not listed in the FDA-approved label. Off-label prescribing is legal and common when supported by clinical evidence.
Oral Ketamine
Sublingual or oral lozenge/troche formulations of ketamine, often compounded by specialty pharmacies. Bioavailability is roughly 20-30% compared to IV; commonly used for at-home maintenance treatment under physician supervision.
P
PHI
Protected Health Information — any individually identifiable health information transmitted or maintained in any form by a HIPAA-covered entity.
Physician Licensure
State-level legal authorization to practice medicine, granted by a state medical board after verification of education, training, examinations (USMLE/COMLEX), and background.
Primary Care
First-contact, comprehensive medical care typically delivered by family medicine physicians, internists, or pediatricians. Functions as the patient's main point of entry into the healthcare system.
Psychiatric Evaluation
A structured clinical interview by a psychiatrist or qualified mental-health clinician to assess symptoms, history, risk, and treatment options. Required before initiating most psychiatric treatments including ketamine treatment.
PTSD
Post-Traumatic Stress Disorder — a psychiatric condition that may develop after exposure to a traumatic event, characterized by intrusive memories, avoidance, negative mood changes, and altered arousal/reactivity. Affects roughly 6% of U.S. adults in their lifetime.
T
Telehealth
Delivery of clinical services over phone or video. Telehealth visits require the prescriber to be licensed in the state where the patient is physically located at the time of the visit.
Telemedicine
Often used interchangeably with telehealth; sometimes scoped specifically to clinical-care services delivered remotely (vs. broader 'telehealth' which includes education, administrative meetings, etc.).
TMS
Transcranial Magnetic Stimulation — an FDA-cleared, non-invasive brain stimulation therapy delivered through magnetic pulses applied to the scalp. Used for major depression, OCD, and smoking cessation.
Treatment-Resistant Depression (TRD)
A subtype of major depressive disorder defined by inadequate response to at least two adequate trials of antidepressant medications from different classes.