Biochemical factors in anxiety neurosis

Autonomic balance revisited: panic anxiety and heart rate variability

The analysis of heart rate variability (HRV) is becoming widely used in clinical research to provide a window into autonomic control of HR. This technique has been valuable in elucidating the autonomic underpinnings of panic disorder (PD), a condition that is marked by reports of heart palpitations. A body of research has emerged that implicates a relative reduction in HRV and cardiac vagal tone in PD, as indicated by various HRV measures. These data are consistent with the cardiac symptoms of panic attacks, as well as with developmental evidence that links high vagal tone with enhanced attention, effective emotion regulation, and organismic responsivity. Implications of these findings for nosology and pathophysiology are discussed. Reports of reduced HRV in PD contrast with portrayals of excess autonomic lability in anxiety. This contradiction is addressed in the context of traditional homeostatic models versus a systems perspective that views physiologic variability as essential to overall stability.

Alcoholism and panic disorder: is the comorbidity more than coincidence?

Studies on alcoholic patients have found a higher than expected prevalence of panic disorder, and suggest a positive correlation between the level of alcohol consumption and severity of anxiety. Conversely, there is an increased prevalence of alcoholism among patients with panic disorder and their blood relatives. A comparison of symptoms, physiological and neurochemical changes known to occur in both alcohol withdrawal and panic disorder reveals a degree of similarity between the 2 conditions. Based on the data, we propose that the chemical and cognitive changes occurring as the result of repeated alcohol withdrawals may kindle and condition coincidence of panic attacks in susceptible individuals. Implications of our postulates for treatment of alcohol withdrawal and panic disorder in alcoholics and for future studies are discussed.

Hyperventilation and panic disorder

Hyperventilation syndrome and panic disorder are both common, serious, and easily treatable disorders. The similarity of their symptoms and physiology, the demonstration of hyperventilation during spontaneous and laboratory-induced panic episodes, provocation of panic-like symptoms in some patients with panic disorder using hyperventilation, the importance of psychologic factors in producing hyperventilation, and successful treatment of panic disorder with breathing retraining all indicate a strong association between these two conditions. About 50 percent of patients in each group show evidence of both disorders. It is suggested that many patients in each group show evidence of both disorders. It is suggested that many patients with either diagnosis have the same disorder and share a biologically and often genetically determined hypersensitivity of a central "alarm" system. Panic and hyperventilation provoked by inappropriate activation of this system are postulated to reinforce each other by a positive feedback loop. Treatments directed at any part of this loop are likely to be successful. Clinical implications of the link between these conditions are discussed.

The biological basis of anxiety. An overview

The DSM-III divides anxiety disorders into two broad categories, Phobic Disorders and Anxiety States. Anxiety states characterised by panic attacks have been separated from generalised anxiety disorders. While this classification may not be generally accepted it is of heuristic value. Delineation of panic disorder as a distinct diagnostic entity has led to renewed efforts to identify a biological cause for the sudden severe somatic and psychological symptoms experienced by these patients. A review of evidence for the involvement of the major neurotransmitter systems is presented. Systematic investigations in DSM-III defined groups of patients are only beginning to be reported. It is difficult as yet to draw any definite conclusions, but some tentative evidence for abnormalities of the noradrenergic system and the GABA-benzodiazepine chloride ionophore receptor complex are emerging. The reliable induction of panic attacks by chemical agents provides the promise of a greater understanding of the possible biological mechanisms involved in this anxiety disorder.

The role of endorphins in exercise: a review of current knowledge

Exercise training is used increasingly to prevent and treat disease, and millions of healthy persons participate in various aerobic-type sports; yet, the mechanisms by which exercise produces various clinical effects is imperfectly understood. Emerging evidence suggests that the endogeneous opioid endorphins may be involved in two widely varying aspects of exercise: endocrine control and behavior and mood adaptation. The present paper summarizes these findings. The relationship of endorphins and adrenocorticotropin to stress and the aspects of endorphins' involvement in the concept of "runner's high" are discussed. J Orthop Sports Phys Ther 1983;4(3):169-173.

Tranquilizer Effect of Exercise: A Critical Review

In brief: Evidence suggests that none of the currently used tranquilizer drugs can be used without risking side effects and/or addiction. Many people have contended that physical exercise relieves anxiety, but until recently no experimental evidence has supported this subjective conclusion. Dr. deVries examined this hypothesis by reviewing available data and surveys of expert opinion and controlled psychological and physiological experiments. He believes that appropriate types, intensities, and durations of exercise can produce a significant tranquilizer effect. Rhythmic exercise such as walking, jogging, cycling, and bench stepping for 5 to 30 minutes at 30% to 60% of maximum intensity was most effective.