Anxiety defined

SmoUer JW, Tsuang MT (1998) Panic and phobic anxiety defining phenotypes for genetic studies. Am J Psychiatry 155 1152-1162... 

To examine whether the new degree of anxiety defined by Eq. (6.7) can express the appropriate degree of anxiety. 

Generalized anxiety disorder has been relatively neglected from the point of view of both health economics and pharmacoeconomics. The changing diagnostic criteria have made it difficult to compare data over time, leading researchers to focus on the more clearly defined disorders such as panic and obsessions. Drug treatment has been dominated by the benzodiazepines, usually available genetically and cheaply. However, as the final section of this chapter will show, all this is in flux. 

Table 32.1 describes 30 persons who have been observed to use one of four available therapeutic compounds for the treatment of one of three possible disorders. The four compounds in this measurement table are the benzodiazepine tranquillizers Clonazepam (C), Diazepam (D), Lorazepam (L) and Triazolam (T). The three disorders are anxiety (A), epilepsy (E) and sleep disturbance (S). In this example, both measurements (compounds and disorders) are defined on nominal scales. Measurements can also be defined on ordinal scales, or on interval and ratio scales in which case they need to be subdivided in discrete and non-overlapping categories. 

If you look in the medical literature, you will often see the term placebo defined as a non-specific treatment. What does it mean to say that a treatment is not specific It could mean that the treatment is effective for many different disorders, rather than for only one particular condition. In this sense, placebos are indeed non-specific. Besides depression, placebos have been shown to affect anxiety, pain, ulcers, irritable bowel syndrome, Parkinson s disease, angina, autoimmune diseases, Alzheimer s disease, rheumatoid arthritis, asthma, gastric function, sexual dysfunction and skin conditions. We know this from the thousands of studies in which placebos have been used as control conditions, against which the effects of medication have been evaluated, and from studies that were specifically designed to assess the placebo effect. 

Neuropeptide S (NPS) is a recently discovered bioactive peptide that has emerged as a new signaling molecule in the complex circuitry that modulates sleep-wakefulness and anxiety-like behavior. The peptide precursor is expressed most prominently in a novel nucleus located in the perilocus coeruleus, a brain structure with well-defined functions in arousal, stress, and anxiety. NPS was also found to induce anxiolytic-like behavior in a battery of four different tests of innate responses to stress. Infusion of NPS potently increases wakefulness and suppresses non-REM (NREM) and REM sleep (Xu et al, 2004). NPS binds to a G-protein-coupled receptor, the NPS receptor, with nanomolar affinity activation of the receptor mobilizes intracellular calcium. The NPS receptor is expressed throughout the brain, particularly in regions relevant to the modulation of sleep and waking, in the tuberomammillary region, lateral hypothalamus, and medial thalamic nuclei. 

Animal models of fear and anxiety have primarily used the rat, the mouse and, to a lesser extent, nonhuman primates. It is not particularly difficult to evoke or measure anxiety in these species. However, difficulties arise when one attempts to define exactly how a stimulus and resultant behavioral response are related to human behavior, i.e. when a mouse exhibits freezing behavior to an unfamiliar and threatening cue, what is the human equivalent Or, similarly, what stimulus could one present to a rat to best model the anxiety-inducing-experience of... 

BZ dependence is defined by the appearance of a predictable withdrawal syndrome (i.e., anxiety, insomnia, agitation, muscle tension, irritability, nausea, malaise, diaphoresis, nightmares, depression, hyperreflexia, tinnitus, delusions, hallucinations, and seizures) upon abrupt discontinuation. 

DSM-IV defines social anxiety disorder as an excessive fear of scrutiny by others in social situations. Refer to Table 5.9 for the diagnostic criteria for social anxiety... 

In this chapter, we consider categorical anxiety disorders as defined by the standardized diagnostic criteria of American Psychiatric Association s Diagnostic and Statistical Manual for Psychiatric Disorders [i.e., DSM-III (1980), DSM-III-R (1987), DSM-IV (1994)]. The subtypes of anxiety states included are panic disorder, agoraphobia, specific phobia, social phobia, generahzed anxiety/overanxious disorder, separation anxiety, and obsessive-compulsive disorder. 

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