Affect
A feeling, mood, or emotion, or the visible, outward appearance of feeling.

Alzheimer's disease
Named for Dr. Alois Alzheimer, who first described the disease in 1907, Alzheimer's disease causes gradually increasing dementia, including memory loss, confusion, problems with judgment, planning and concentration, and personality changes; in its later stages it also affects physical abilities. The disease's causes, cures and preventions are unknown.

Antidepressants
Medicines developed to treat depression. They are prescribed based on the particular diagnosis of a patient and administered under appropriate risk management models. In some cases, such as, depression caused by a neurochemical imbalance – anti-depressants might be essential for a favorable outcome. Usually, treatment must continue for several weeks before full therapeutic effect can be measured.

Antipsychotic
A medication that works to relieve symptoms such as delusions, racing thoughts, hallucinations, paranoia and other symptoms that may appear during mania or depression.

Anxiety disorder
A chronic condition characterized by an excessive and persistent sense of apprehension with physical symptoms such as sweating, palpitations, and feelings of stress. Anxiety disorders have biological and environmental causes.

Atypical
A form of depression or bipolar disorder that does not follow usual or expected patterns.

Bipolar
A disorder characterized by switching between the two extremes or "poles" of mania, a highly active or agitated state, and depression, a sad, withdrawn state.

Cognitive behavioral therapy (CBT)
A type of psychotherapy to help the patient identify and change pessimistic thoughts and beliefs that can lead to depression and help the patient develop "coping" techniques.

Confusion
The inability to think with your usual speed or clarity. When confused, you will also have difficulty focusing your attention and you may feel somewhat disoriented. Confusion interferes with your ability to make decisions.

Delirium
A change in thinking or consciousness that develops over a few hours or days. It is not a disease but develops as the result of an acute medical condition or drug toxicity.

Delusion
False belief firmly held by a person even though others recognize the belief to be clearly untrue. Delusions may be part of mania, dementia or depression.

Dementia
Significant loss of intellectual abilities such as memory capacity, severe enough to interfere with daily life. The symptoms of dementia can include changes in personality, mood and behavior. Disease and injury cause irreversible dementia. But dementia caused by drugs, alcohol, hormone imbalances, vitamin deficiencies or depression may be reversible.

Depression
A potentially serious mental health condition that involves the body, mind and emotions. Often characterized by a profound change in mood and/or a profound loss of interest in once-pleasurable things or activities. Depression can affect the way you eat, sleep and function; how you feel about yourself and others; and what think about the world around you.

Dissociative disorders
A group of mental disorders where people chronically escape their reality in involuntary, unhealthy ways ranging from suppressing memories to assuming alternate identities. The patterns of dissociative disorders usually develop as a reaction to trauma and function to keep difficult memories at bay.

Dysthymia (dysthymic disorder)
An illness characterized by a chronically depressed mood for most of the day, more days than not, for at least two years, with symptom-free periods lasting less than two months. Dysthymia may be difficult to identify or diagnose because the person may believe that sadness is part of his or her personality. While dysthymia is not as severe as major depression, it can be just as disabling.

Electroconvulsive therapy (ECT)
Statistically the most effective treatment for depression. Produces a seizure in the brain of the patient (who is under general anesthesia) by applying electrical stimulation via electrodes placed on the scalp. Repeated treatments are necessary to achieve the most complete desired response. Memory loss and other cognitive problems are common yet typically short-lived side effects.

Electrolyte
Salts and minerals that can conduct electrical impulses in the body. Common human electrolytes are sodium chloride, potassium, calcium, and sodium bicarbonate. Electrolytes control the fluid balance of the body and are important in muscle contraction, energy generation, and almost every major biochemical reaction in the body.

Hallucination
Seeing or hearing things that are not there. Hallucinations may occur with severe mania, or with depression that has psychotic features.

Hypothermia
Abnormally low body temperature. The condition needs treatment at body temperatures of 35C (95 F) or below. And hypothermia becomes life threatening below body temperatures of 32.2 C (90 F).

Ideation
The process of forming and relating thoughts, feelings ideas. This term "suicidal ideation" is often used to describe the symptom of depression in which a person becomes obsessed with death and motivated to take his or her own life. This symptom needs to be treated immediately.

Interpersonal therapy
Therapy to improve problems in relationships that may be contributing to the depression.

Mental
Relating to the mind.

Mood disorders
Used to describe the wide variety of depressive states possible because of the numerous possible symptoms and combinations of symptoms that a patient might exhibit as someone suffering from depression or anxiety.

Neurochemical disorder
An identifiable and measurable chemical imbalance in the brain, which causes depression. Neurochemical disorders tend to be responsible for most severe cases of depression, usually marked by major changes in personality, detachment from reality and similar symptoms. A neurochemical imbalance might be suspected when the person's circumstances don't seem to warrant depression.

Neurotransmitters
Chemicals that are used to relay, amplify and modulate electrical signals between brain cells. Many medications for mood disorders adjust the amounts of certain neurotransmitters in the brain, including serotonin, norepinephrine, and GABA (gamma-aminobutyric acid).

Personality dysfunction
Associated with more severe cases. Depression can trigger sometimes dramatic changes in personality – from happy-go-lucky to deep sadness, from calm and reserved to talkative and agitated, from rational to irrational. The people in your circle of influence might say they "don't know you anymore."

Problem-solving therapy
Therapy to help the person learn more effective ways to manage problems.

Psychiatrist
A medical doctor (MD) who specializes in illnesses of the brain and the medications to treat them.

Psychologist/psychotherapist
A trained and licensed professional (PhD, MSW, LCSW, EdD, and other advanced degrees) who specializes in talk therapy. Most psychologists cannot prescribe medication, but they can offer a great deal of help through therapy.

Psychosis
A treatable condition in which a person may be confused and have delusions or hallucinations. Psychosis may co-occur with mania or depression. Although it is often a temporary state, people experiencing psychosis should get immediate treatment to avoid putting themselves or others in danger.

Psychotherapies
Also referred to as the "talking" therapies. The goal is to help patients "talk through" their illness and their circumstances, overcoming unwarranted fears, feelings of anxiety or inadequacy and the like. Patients also can be "trained" in certain life skills that help them recognize, address and overcome aspects of their depression and lead more well-adjusted lives.

Psychotic depression
A severe major depressive that is accompanied by delusions (believing things that are not true, such as that people are out to get you) or hallucinations (seeing or hearing things that are not there). Psychotic depression is most common in late life.

Schizophrenia
One of several brain diseases whose symptoms that may include loss of personality (flat affect), agitation, catatonia, confusion, psychosis, unusual behavior, and withdrawal. The illness usually begins in early adulthood. The causes of schizophrenia are not yet fully known.

Supportive psychotherapy
Therapy aimed at providing emotional support to help the person cope with and resolve difficulties that may worsen the depression

Treatment-resistant depression
The continuation of depression symptoms despite treatment with at least three or four different medications.