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KRISTINA SUNDQUIST, GÖLIN FRANK, and JAN SUNDQUIST
Urbanisation and incidence of psychosis and depression: Follow-up study of 4.4 million women and men in Sweden
The British Journal of Psychiatry 2004; 184: 293-298 [Abstract] [Full text] [PDF]
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[Read eLetter] Increased testosterone may be the cause...
James M. Howard   (9 April 2004)
[Read eLetter] Destigmatizing campaigns, urbanisation and psychosis!
Dr.Naseem A. Qureshi   (19 April 2004)

Increased testosterone may be the cause... 9 April 2004
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James M. Howard,
biologist
independent

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Re: Increased testosterone may be the cause...

jmhoward{at}arkansas.net James M. Howard

Increased testosterone may be the cause of the findings of Sundquist, et al., that is, that “A high level of urbanisation is associated with increased risk of psychosis and depression for both women and men.” Two hypotheses are required to explain this. It is my hypothesis that human evolution is driven by testosterone ("Androgens in Human Evolution," Rivista di Biologia / Biology Forum 2001; 94: 345-362). Based on this, I suggest the "secular trend," the increase in size and earlier puberty of children, is actually an increase in the percentage of individuals of higher testosterone. The “trend” may actually be a change in percentage of individuals within our populations and their “characteristics” may also be increasing. This phenomenon occurs when a "feed and breed" environment occurs. In these situations, individuals of higher testosterone, men and women, will increase more rapidly than those of lower testosterone over time. (Individuals of higher testosterone are more aggressive and sexual; they will increase in percentage with time.) Urban areas are "feed and breed" centers. I suggest urban centers are areas of higher testosterone.

It is my hypothesis that dehydroepiandrosterone (DHEA) is directly involved in growth and development, and subsequent maintenance, of all tissues, especially the brain. (The large brain of mammals may have resulted from an evolutionary increase in DHEA (“Hormones in Mammalian Evolution,” Rivista di Biologia / Biology Forum 2001; 94: 177-184). Numerous reports of beneficial effects of DHEA on neurons and tissue-level structures of the brain exist in the literature. I have suggested in the past that depression and schizophrenia, among other mental diseases, result from low DHEA during growth and development, subsequently exposed by adverse circumstances during maintenance. DHEA is low in depression and schizophrenia. Two other hormones may adversely affect the function or availability of DHEA: cortisol and testosterone. Over the past few years the connection of low DHEA, along with increased cortisol, have been demonstrated regarding depression. It is known that schizophrenia is often characterized as resulting from a non-causal, but significant, stressful event (cortisol) usually beginning in the late teens or early twenties (testosterone of puberty, in men and women, along with the natural decline of DHEA which begins around age twenty). In individuals of low DHEA, increased cortisol and testosterone may expose underlying, silent pathology.

Therefore, I suggest that increased rates of psychoses and depression in urban areas may be the product of increased stress and testosterone in both men and women. As suggested above, the secular trend may be due to increasing numbers of individuals of higher testosterone. This increase in these individuals of higher testosterone, along with increasing stress of urbanization, may account for the findings of Sundquist, et al., as well as reports of current increases of these mental disorders.

Destigmatizing campaigns, urbanisation and psychosis! 19 April 2004
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Dr.Naseem A. Qureshi,
Medical Director [A], Director, CME&R
Buraidah Mental Health Hospital, Saudi Arabia

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Re: Destigmatizing campaigns, urbanisation and psychosis!

qureshinaseem{at}hotmail.com Dr.Naseem A. Qureshi

Dear Sir: I read with interest an article by Sundquist and her colleagues. First, this study is highly impressive in the sense that it fulfills almost all statistical requirements for estimating accurately the incidence and prevalence of a complex mental disorders such as psychosis and depressive disorder. Secondly, the findings of this study can be generalized to at least all European countries and other developed nations.

Notably, by and large the etiology of complex psychiatric disorders such as schizophrenia and mood disorders until now is speculative and more often an array of biological, psychological and sociocultural factors have been evoked in the etiopathogenesis of these disorders [Qureshi, 1981]. Urbanisation,i.e destroying rural quality of a district as an environmental factor has a long history of its association with increased incidence of psychosis and depression, though some studies have reported inconsistent results. Furthermore, a selective review of literature of the past five decades suggests that incidence of psychosis is rather low in rural areas. Moreover, the WHO International Pilot Studies on Outcome of Schizophrenia have attested this fact and have also reported that the outcome of psychosis is relatively better in developing countries where urbanisation is a slow process, which is not coupled with greater stressors. We have also reported the similar results [Qureshi,Prakash & Sethi,1990].

Besides many other factors which explain the increased incidence of psychosis and depression in urban areas, mental disorder destigmatising campaigns, mental disorder awareness programs, and early screening programs for mental diseases have definite impact on the incidence of psychosis and depression. Obviously, these programs are more often directed at urban population. The other relevant factor which could explain this epidemiological trend is the revealed pattern of rather benign symptomatology of psychosis and depression among rural patients in particular female gender and most importantly unaffected family members and also people living in rural areas are reported to have a high index of tolerability of their kith and kin with mental disorders including psychosis and depression.

Declaration of interest:none

Reference:

Sundquist K, Frank G, & Sundquist J.Urbanisation and incidence of psychosis and depression: Follow-up study of 4.4 million women and men in Sweden. Br J Psychiatry 2004; 184: 293-298

Qureshi NA. Etiology of schizophrenia. J Comm Psychiatry(Mumbay)1981; Jan-March: 25-32.

Qureshi NA, Prakash R, Sethi BB. A follow-up study of schizophrenia. Arab J Psychiatry 1990; 1: 190-200.

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