DA - see dopamine.

DaCosta's Syndrome - an alternate name for post traumatic stress disorder or panic disorder dating back to the American Civil War.

Daymare - a daydream or fantasy which produces intense anxiety. Regular or frequent daymares can be a feature of obsessive thinking. Contrast with nightmare.

Deep Muscle Relaxation - see progressive muscle relaxation.

Degeneration - a 19th century Victorian belief that the hereditary transmission of mental illness might pose a serious danger to society.

Dehydroepiandrosterone (DHEA) - a hormone that is abundant at infancy and young adulthood. Some believe that supplements of DHEA may increase youthful vigor, but the effects of such supplements are not yet understood.

Deimos - a god from Greek mythology who personified fear, especially demoralization in the midst of conflict. Son of Ares (Mars) and Aphrodite (Venus). Brother of Phobos. Latin, Deimus. Roman, Formido or Metus. Also see mythology.

Deja Vu - a sense that something encountered for the first time is somehow familiar. Contrast with jamais vu.

Delusion - a false belief that is maintained in spite of contrary evidence.

Demoralization - feelings of being ineffective, inadequacy at solving problems, and inability to control one's life. Demoralized individuals become discouraged, frustrated, ashamed or unhappy about the difficulties of carrying out their normal routines. Such feelings are a frequent consequence of chronic anxiety disorders or depression. Also see nostalgia.

Dependence - any physical or psychological need or craving for a substance or behavior to maintain functionality or minimize adverse effects of a disorder. Some forms of dependence are innate (e.g. air, water, food), the product of a disorder (e.g. insulin) or acquired through excessive exposure (i.e. addiction). Also see withdrawal syndrome.

Depersonalization - an altered and unreal perception of ourselves, our feelings and/or our situation. Sometimes described as a loss of personal identity or feeling that one is someone else. In one person's words, "feeling like you are on the outside looking in, as your perception is altered. The real sense was that things were going on around me, but I didn't feel that I was there." Contrast with derealization. Also see hypervigilance.

Depression - a sense of unhappiness; ranging from mild anhedonia to a profound sense of futility and worthlessness. Chronic depression can be psychological or psychiatric. Depression is associated with anxiety and panic disorders in many cases. Adj. Depressive.

Derealization - an altered and unreal perception of things and objects around us in space/time. Contrast with depersonalization. Also see hypervigilance.

Desensitization - reducing sensitivity to a stressor through repeated exposure. See exposure therapy.

DHEA - see dehydroepiandrosterone.

Diagnosis - identification of an illness or disorder. Contrast with prognosis. Anxiety disorders are difficult to diagnose because their symptoms are similar to many other conditions. Anxiety disorders are not tested for directly, but are diagnosed by ruling out other conditions with similar symptoms. Consequently, the proper diagnosis of anxiety disorders often involves a number of medical tests under the supervision of a diagnostician or a general practice doctor. Conditions that are often ruled out include cardiac disorder, epilepsy, Epstein Barr virus, hypoglycemia, hypotension, Lyme disease, pernicious anemia, pheochromocytoma, porphyria, postpartum depression, respiratory disease, seasonal affective disorder, streptococcus infection, thyroid disorder.

Diagnostic and Statistical Manual (DSM) - the most respected reference for diagnosis of psychiatric disorders. Published by the American Psychiatric Association (APA), the DSM presents theoretical definitions of disorders; describing biological, psychological, and social aspects of various conditions. This manual has been dramatically revised since its first three editions, so only the more recent editions (DSM-III-R and DSM-IV) should be used in clinical settings. Contrast with International Classification of Diseases.

Diagnostician - a medical doctor who specializes in diagnosis.

Diathesis - a predisposition to a disorder.

Diet - an array of substances consumed. Contrast with nutrition.

Dionysus - a god from Greek mythology who personified fertility, especially in regard to the vine and, consequently, associated with wine. Son of Zeus (Jupiter) and Semele. Roman, Bacchus (god of wine). He removed inhibitions and freed emotions. Spring is his season of happiness and winter is his season of sadness. Mythical associations of Dionysus with Pan seem ironic when considering the nature of alcohol and seasonal affective disorder. Also see mythology.

Dissociation - a mental response that diverts consciousness from painful or traumatic associations. Such responses may include depersonalization, derealization, amnesia, splitting of identity or even loss of consciousness; in essence, escaping painful associations of reality by going to another real or imaginary place.

Distraction - redirecting attention from one thought towards another thought. Distraction can be a helpful psychological technique for reducing anxiety. For example, anticipatory anxiety can often be reduced by shifting attention from negative thoughts to positive thoughts.

Diuretic - any substance that increases urine flow and, therefore, water loss.

Dizzy - a whirling sensation with reduced feeling of balance. Also see vertigo.

Dopamine (DA) - a hormone and neurotransmitter (a catecholamine). In the central nervous system dopamine is involved in functions as diverse as motor control, cognition, and is one of the primary neurotransmitters involved in the reward centers of the brain. DA appears to regulate endorphin levels (perception of pain) and sensations of pleasure. Dysfunctional levels of DA are related to Parkinson's disease, paranoia, memory and concentration problems. DA blockade is the mechanism of action of the antipsychotic drugs. For biosynthesis details see tyrosine. Also see oxytocin, prolactin.

Dose - amount of a substance. Also see BID, pharmacokinetic, PRN, QD, QID, ramped dosage, taper, therapeutic dosage, TID, TIDM.

Double Blind Study - a study in which neither the investigator nor the subject know whether a medication or placebo is being used for any given subject. This prevents bias on the part of the subject and investigator.

Dread - a powerful anticipatory fear.

Dream - thoughts or experiences which occur when sleeping. Also see bad dream, daymare, nightmare, Oneroi, REM, sleep.

Dream Analysis - the analysis of dreams in an effort to discover unconscious meanings or symbolic associations. Also known as oneirology. Dream analysis can vary greatly depending on the underlying theory used to interpret dreams. Generally, some dreams are more meaningful than others, and some dreams may have no significant meaning at all. Within psychotherapy, the dreams most likely to have significant meaning are recurrent dreams (i.e. dreams that occur frequently and are somehow similar in content, context or theme).

Drop Attack - see akinetic seizure.

Drug - technically any substance used as a medication, although the word "drug" is sometimes used in a negative connotation (implying addiction, abuse or illicit use). Also see recreational drug.

Drug Dealer - commonly, anyone who provides recreational drugs.

Druggist - see pharmacist.

Drug Marketing Representative - see pharmaceutical representative.

Drug Representative - see pharmaceutical representative.

Drug Sales Representative - see pharmaceutical representative.

DSM - see Diagnostic and Statistical Manual.

Dysautonomia - any irregularity in the autonomic nervous system. This term applies to the somatic symptoms of anxiety such as sensory deficiencies, perspiration, hyperventilation, salivation, tachycardia.

Dysesthesia - an unpleasant sensation which may resemble prickling, itching, burning, or electrical shock. Also see brain zap, paresthesia.

Dyskinesia - impaired voluntary movement involving muscular spasms.

Dysphoria - feeling unwell or unhappy. Opposite of euphoria. Adj. Dysphoric.

Dysthesia - see dysesthesia.

Dysthymia - chronic depression or irritability, punctuated by periods of healthy mood and function.