Glossary

Plain-language definitions of mental health terms used across this site. Each definition is general educational content and not a clinical diagnosis or recommendation.

Amygdala
A small almond-shaped cluster of brain cells deep in the temporal lobe. It plays a central role in detecting potential threats and triggering rapid responses.
Anxiety
A felt state of activation and worry that varies from a normal human emotion to a clinical disorder. Anxiety becomes a clinical concern when it interferes with daily life.
Autonomic Nervous System
The part of the nervous system that controls automatic body functions like heart rate, breathing, and digestion. It has two main branches: sympathetic (activating) and parasympathetic (settling).
Board Certification
A formal recognition that a physician has met the standards of a specialty board, including passing examinations and completing accredited training. Board certification is voluntary and is separate from state medical licensure.
Cognitive Arousal
The state of having an active, alert mind. Pre-sleep cognitive arousal is one of the strongest predictors of insomnia.
Cognitive Behavioral Therapy (CBT)
An evidence-based therapy approach that helps people identify and modify unhelpful thinking and behavioral patterns. CBT is delivered by trained licensed clinicians.
Cognitive Defusion
A technique from acceptance and commitment therapy that helps a person put space between themselves and their thoughts, rather than treating each thought as a literal truth.
Cortisol
A hormone produced by the adrenal glands that follows a daily rhythm and rises in response to stress.
Depression
A clinical condition characterized by persistent low mood, loss of interest or pleasure, and other changes in sleep, appetite, energy, and concentration. Depression varies in severity and benefits from clinical evaluation.
Dialectical Behavior Therapy (DBT)
An evidence-based therapy approach combining cognitive techniques with mindfulness and emotion regulation skills.
Evidence-Based
Refers to approaches that have been studied in research and shown to be helpful for specific conditions. Evidence-based treatments are the standard in modern clinical care.
Exposure and Response Prevention (ERP)
An evidence-based therapy for obsessive-compulsive disorder. It involves gradual exposure to feared situations or thoughts while preventing the compulsive response.
High-Functioning Anxiety
Not a formal diagnosis. A descriptive pattern in which a person experiences chronic anxiety while continuing to perform well in work and life. Often invisible to the people around them.
Hypervigilance
A state of elevated alertness to potential threats. The system stays in scan mode even when no specific danger is present.
Intrusive Thoughts
Unwanted thoughts that arrive without permission and often clash with a person's values. Common across the general population. When persistent and distressing, they can be a feature of obsessive-compulsive disorder.
Medication Management
The clinical process of evaluating, prescribing, monitoring, and adjusting psychiatric medications. Medication management requires a licensed prescriber. For plain-language information on specific psychiatric medications, see PsychiatryRx.org.
Obsessive-Compulsive Disorder (OCD)
A clinical condition characterized by intrusive thoughts (obsessions) and repetitive behaviors or mental acts (compulsions) performed to reduce distress. Responds well to specific evidence-based approaches.
Panic Attack
A sudden episode of intense fear or discomfort accompanied by physical symptoms like racing heart, shortness of breath, sweating, or feelings of unreality. Panic attacks can occur with or without a panic disorder diagnosis.
Panic Disorder
A clinical condition characterized by recurrent unexpected panic attacks and persistent concern about future attacks.
Parasympathetic Nervous System
The branch of the autonomic nervous system that slows the heart, deepens breathing, and supports digestion, repair, and rest.
Prefrontal Cortex
The part of the brain behind the forehead involved in deliberate reasoning, decision-making, and impulse control. Engagement with the prefrontal cortex can be reduced during high-activation states.
Post-Traumatic Stress Disorder (PTSD)
A clinical condition that can develop after exposure to traumatic events. Includes symptoms like intrusive memories, avoidance, changes in mood, and changes in arousal. Responds to specific evidence-based approaches.
Psychiatrist
A medical doctor (MD or DO) who specializes in mental health. Psychiatrists can prescribe medication, diagnose conditions, and provide therapy.
Rumination
Repetitive, often unproductive thinking about the same topic. Rumination differs from reflection in that it loops without converging on a conclusion.
SSRI
Selective serotonin reuptake inhibitor. A class of antidepressant medication. For plain-language, psychiatrist-reviewed guides to specific SSRIs and other psychiatric medications, see PsychiatryRx.org.
Sympathetic Nervous System
The branch of the autonomic nervous system that activates the body for action, including raising heart rate and mobilizing energy.
Telepsychiatry
The delivery of psychiatric care through video, phone, or other remote technologies. Telepsychiatry outcomes are comparable to in-person care for most common conditions.
Therapist
A licensed mental health clinician who provides talk therapy. Therapists generally don't prescribe medication.
Vagal Tone
A measure of activity in the vagus nerve, which is part of the parasympathetic nervous system. Higher vagal tone is generally associated with better stress recovery.
Vagus Nerve
A major nerve of the parasympathetic nervous system, running from the brainstem through the body and influencing heart rate, digestion, and other functions.

This glossary is general educational reference and isn't a diagnostic tool. For any specific condition or symptom, please consult a licensed clinician.