Psychogenic mechanisms

To understand the phenomenon of MCS will require interaction among many disciplines to allow for the examination of the influence of the mind on the body and the influence of physical disease on the psyche. Illness should not be regarded as less real because psychogenic mechanisms may play a major role in... 

Major depression is a complex disorder with a highly variable course and an inconsistent response to treatment—and no established biogenic or psychogenic mechanism.55 We really don t understand it, we don t know how to treat it in all cases, and we don t know what causes it. We have only some intriguing correlations. 

GAD is primarily felt to be a psychogenic disorder. However, there is some speculation that at least some GAD patients may suffer from a biologically mediated disorder. One hypothesis is that mentioned above a deficiency of neurochemicals. Another model has emerged more recently. Treatment with serotonin agonists such as buspirone and 5-HT antidepressants (SSRI s) has been shown to reduce "what-ifing" (worry) in some GAD patients. However, the mechanism of action and underlying pathophysiology are not well understood. 

Erection occurs as a result of increased pressure in the corpora cavernosa, which translates into penile rigidity. The pressure increase is caused by three synergistic processes (i) relaxation of the smooth muscles of the corpora cavernosa (2)increase in arterial blood flow to the penis and (5) restriction of the venous blood flow out of the penis. Both central and peripheral mechanisms contribute to the process of penile erection. At the central level, the psychological component of penile erection is controlled by the hypothalamic and limbic systems (140). At the peripheral level, both sympathetic and parasympathetic pathways as well as several mediators are involved. Psychogenic and local stimulation results in the release of neurotransmitters from the cavemosal nerve terminals and smooth muscle endothelium. Factors that mediate the corpus cavemosum relaxation include nitric oxide (NO), vasoactive intestinal peptide (VIP), calcitonin gene-related peptide (CGRP), and prostaglandin. 

A common mechanism may underlie the psychogenic action of the indole type hallucinogens on the one hand and the compounds related to adrenaline on the other, but it is not yet possible to say whether this action is related to 5-hydroxytryptamine or to adrenaline. Adrenochrome and adrenolutin have structural similarities with the indoles and, under similar conditions, both LSD and mescaline similarly antagonize the action of 5-hydroxytryptamine on isolated preparations . There is some evidence that LSD... 

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