Etiology of Erectile Dysfunction today: Organic vs. Psychogenic
Organic vs. Psychogenic
Dr. Rajesh Taneja
Senior consultant Urology and Andrology
PSRI Hospital, New Delhi
Erectile Dysfunction (ED) has had the distinction of a disease which occurs as an invisible disorder in an otherwise seemingly normal individual with morphologically normal organ. Historically, this has been interpreted in past as an effect of some kind of an evil spirit or black magic. In the latter half of twentieth century, it was recognized as an organic disorder. Even then, almost 90% of these men were supposed to be suffering from a psychological disorder which was manifesting as ED. However towards the end of last century, medical literature was full of articles and research papers suggesting that a majority of men suffering from ED had an organic etiology. This classification of ED on the ‘Basis of Etiology’ was required to plan the therapeutic strategies in dealing with this disorder. Before the advent, widespread availability and documented safety & efficacy of use of penile prosthesis, ED was considered primarily as a disorder to be treated by psychotherapy and counselling. However, as the advancements in the surgical treatment of ED established effective therapeutic modalities, most of the research papers recognised ED as an organic disorder needing an organic treatment.
Soon after the FDA of USA approved Sildenafil citrate for the treatment of ED in 1998, a new era of understanding of ED was ushered in. Use of Sildenafil has since been recommended as a first line therapeutic trial by most urological guidelines. It was found to have the advantage of treating so called vascular ED in men with compromised cavernosal arteries and at the same time improving their psychological state. In addition patients thought to have a primarily psychological ED were also found to be benefitted by the drug. Thus the primary need of differentiation of ED on the basis of etiology became less important clinically while planning the first therapeutic trial.
The organic and psychogenic factors in the aetiology of ED are well established and are broadly mentioned in table1. It is important to understand the physiology of erections in order to understand the pathogenesis of ED. Reflexogenic erections occurs due to local sensory stimulation, while psychogenic erections occur as a result of central stimulation via visual, auditory, tactile, gustatory and psychic (fantasy) stimuli. In the resting state, cavernosal trabecular smooth muscles are under the influence of Sympathetic Nor Adrenergic nerve (NA) fibers and the non adrenergic, noncholinergic (NANC) fibers. Release of noradrenaline from NA fibers causes contraction of trabecular smooth muscle and perpetuates the flaccid state, while NANC fibers stimulate the release of Nitrous Oxide (NO) which facilitates the relaxation of smooth muscle leading to erection. It is important to emphasize that increased sympathetic activity, which may be due to psychological stress can be overriding, resulting in a failure of erection. Thus it can be argued that Psychological factors are actually capable of an organic disruption in the final cascade leading onto erection. On the other hand, let us examine the case of organic impotence. Any reduction in the erectile function as an event with poor performance can result in disappointment and guilt which may progress to a state of subclinical depression. Once this occurs, it is not unusual to develop anxiety regarding future performance. Any pre-performance anxiety is likely to adversely affect the erectile function and end up in poor performance. Therefore, it may be argued that any patient with organic ED is likely to have an accompanying psychological component, which cannot be ignored as it has a potential to interfere with the final cascade of erection through noradrenergic fibers.
Aging is a learnt behavior. It is well known that certain cultures like in India, sexual activity is expected to decline beyond a certain age and stage of life, e.g. after the children grow up or get married or one becomes a grandparent. It then means that men beyond a certain age would start distancing themselves from the sexual activity. This is purely a psychological state of mind. Less sexual activity may result in faster reduction of testosterone as each ejaculation is expected to push up the testosterone levels. Reduction in testosterone in turn results in cavernosal dysfunction. Thus a seemingly psychological state can be shown to adversely affect the organ in the long run (either use it or lose it).
These are a few arguments to state that the two kinds of factors, organic and psychological do not operate in isolation and in fact are usually coexisting. The distinction between organic and psychogenic was based also on the results of certain investigations which were carried out in laboratory settings which are actually so different from the real time bedroom settings.
The classification of ED based on etiology therefore is not a sharp distinction but rather blurred. Any given case therefore should be classified as primarily organic or primarily psychogenic. The widespread use of Sildenafil as therapeutic trial aims to benefit a significant proportion of both types of cases of ED. However, therapeutic trial should not bypass the standard history and examination to gather useful data like drug induced or obvious psychogenic due to marital discord.
Figure 1 Physiology of Erection
Table 1. Etiology of ED
i) Generalized Unresponsiveness
ii) Generalized Inhibition
i) Partner related
ii) Performance related
iii) Psychogenic distress
Table 2 Clinical differentiation of ED
|Non coital erections
|Anxiety and fear