What are some common terms associated with depression?

The following glossary contains medical definitions to help you understand terms related to the treatment of depression.

Adverse reactions

Any undesired actions or effects of a drug or treatment. Adverse reactions are also known as side effects. They are recorded as the percentage of patients who experience them; for example, if 10 people out of 100 in a clinical trial take a medicine and develop a headache, then 10% of the study participants experienced this adverse reaction.

Antidepressants

Medications that treat depression. There are several different types of antidepressants, such as selective serotonin reuptake inhibitors, serotonin and norepinephrine reuptake inhibitors, tricyclic antidepressants, and monoamine oxidase inhibitors. They vary in how they work, in their side effects, and how they may interact with other medications.

Clinical trial

A research study designed to answer specific questions about new therapies or new ways of using known treatments. Clinical trials are used to determine whether new drugs or treatments are both safe and effective.

Contraindication

A situation in which a drug, procedure, or treatment should not be used because it may be harmful to the patient.

Controlled study

A trial in which a test treatment is compared with a treatment that has known effects. While one treatment group receives the medication being studied, another group, called the control group, receives either no treatment, standard treatment (which may be another medicine or another approach to care), or placebo (sugar pill) in order to compare the effects of different treatments.

Diagnostic and Statistical Manual of Mental Disorders (DSM)

The standard classification reference for mental disorders used by mental health professionals in the United States.

Food and Drug Administration (FDA)

The U.S. Department of Health and Human Services agency responsible for ensuring the safety and effectiveness of all drugs, biologics, vaccines, and medical devices.

Major depressive disorder (MDD)

A serious medical condition that is characterized by a combination of symptoms, including persistent sad, anxious, or "empty" moods; feelings of hopelessness, guilt, or worthlessness; helplessness and loss of interest or pleasure in activities that were once enjoyed. Symptoms of depression interfere with normal functioning and are not associated with other psychiatric conditions, including mixed, manic, or hypomanic episodes.

Major depressive episode

A person with depression has at least 5 of the following symptoms:

• Depressed mood
• Loss of interest or pleasure
• Feelings of worthlessness or guilt
• Agitation or restlessness
• Fatigue or loss of energy
• Trouble thinking, making decisions, or concentrating
• Disturbed sleep, such as insomnia
• Changes in appetite or weight
• Thoughts of death or suicide or suicide attempts

At least one of the symptoms must be "depressed mood" or "loss of interest or pleasure." A person with depression will have experienced these symptoms for at least a 2-week period, and the symptoms will be noticeably different from what the patient experienced in the past.

Montgomery-Asberg Depression Rating Scale (MADRS)

A rating scale used by researchers to assess the severity of depression among diagnosed patients. It is designed to be sensitive to change resulting from treatment.

Neurotransmitter

A chemical in the brain that transmits nerve impulses from one neuron to an adjacent neuron at a place called a synapse.

Norepinephrine

A neurotransmitter and a hormone that aids in the regulation of cognition, motivation, and intellect.

Placebo

A biologically inactive substance administered to some participants in a clinical trial for the purpose of comparing no treatment to active treatment. In a blinded trial, patients do not know whether they are receiving a placebo or the drug being tested.

Psychiatrist

A physician who specializes in the diagnosis and treatment of mental illnesses.

Psychiatry

The medical specialty concerned with the diagnosis and treatment of mental illnesses.

Psychologist

A person trained in the study of the mind and behavior in relation to different areas of human activity, including the family, education, and employment and also trained in the treatment of mental health problems.

Psychotherapist

A professionally trained and licensed person who uses a variety of techniques to improve the mental health and coping skills of their patients. Psychotherapists come from diverse backgrounds and include psychologists, counselors, social workers, and psychiatrists.

Psychotherapy

Treatment of emotional, behavioral, personality, and psychiatric disorders in the context of an established therapeutic relationship between a psychotherapist and client/group. Most forms of psychotherapy use verbal communication; interpersonal and cognitive-behavioral therapies are among the most common.

Selective serotonin reuptake inhibitor (SSRI)

A class of antidepressants used to treat major depressive disorder. SSRIs are thought to work by inhibiting the reuptake of serotonin, an action which allows more serotonin to be available to be taken up by other nerves.

Serotonin and norepinephrine reuptake inhibitor (SNRI)

A class of antidepressants used to treat major depressive disorder. SNRIs are thought to work by inhibiting the reuptake of serotonin and norepinephrine.

Serotonin

A neurotransmitter that aids in the regulation of mood, appetite, sleep, muscle contraction, and some brain functions, including memory and learning.

Sheehan Disability Scale (SDS)

A self-rated scale, designed to measure the extent to which a patient’s functioning is impaired by depressive symptoms in three major categories: work/school life, social life, and family/home life.