Study sug­gests smok­ing- men­tal ill­ness link

Townsville Bulletin - - NEWS -

CHEM­I­CALS in to­bacco may help trig­ger se­ri­ous men­tal ill­nesses such as schizophre­nia, a study sug­gests. New re­search shows that smok­ing can triple the chances of de­vel­op­ing psy­chosis.

Pre­vi­ously the fact that peo­ple with psy­chotic men­tal ill­nesses are more likely to smoke has been put down to non- causal fac­tors, such as ob­tain­ing re­lief from dis­tress or self- med­i­ca­tion.

But now sci­en­tists be­lieve some­thing in to­bacco might ac­tu­ally be re­spon­si­ble, along­side ge­netic and en­vi­ron­men­tal in­flu­ences. “Our find­ings in­di­cate that smok­ing should be taken se­ri­ously as a pos­si­ble risk fac­tor for de­vel­op­ing psy­chosis, and not dis­missed sim­ply as a con­se­quence of the ill­ness,” said Dr James MacCabe, a mem­ber of the team from King’s Col­lege Lon­don. The re­searchers an­a­lysed data from 61 ob­ser­va­tional stud­ies in­volv­ing al­most 15,000 to­bacco users and 273,000 non- users. They found that 57 per cent of peo­ple treated for a first episode of psy­chosis were smok­ers. Psy­chotic pa­tients were three times more likely to con­sume to­bacco than in­di­vid­u­als with­out se­vere men­tal ill­ness. The study also showed that daily smok­ers be­came psy­chotic around a year ear­lier than non­smok­ers.

The sci­en­tists, whose find­ings are re­ported in The Lancet Psy­chi­a­try med­i­cal jour­nal, ac­knowl­edge that causal­ity is dif­fi­cult to prove.

One the­ory is a pos­si­ble link be­tween smok­ing and ex­cess dopamine, a brain chem­i­cal that plays a role in trans­mit­ting nerve sig­nals.

Pro­fes­sor Sir Robin Mur­ray, from the In­sti­tute of Psy­chi­a­try, Psy­chol­ogy and Neu­ro­science at King’s Col­lege, said: “Ex­cess dopamine is the best bi­o­log­i­cal ex­pla­na­tion we have for psy­chotic ill­nesses such as schizophre­nia. It is pos­si­ble that nico­tine ex­po­sure, by in­creas­ing the re­lease of dopamine, causes psy­chosis to de­velop.” A proven link has al­ready been found be­tween cannabis use and psy­chosis in ge­net­i­cally vul­ner­a­ble peo­ple.

Dr Sameer Jauhar, another mem­ber of the King’s Col­lege team, said: “Longer- term stud­ies are re­quired to in­ves­ti­gate the re­la­tion­ship be­tween daily smok­ing, spo­radic smok­ing, nico­tine de­pen­dence and the de­vel­op­ment of psy­chotic dis­or­ders.

“Ev­ery ef­fort should be made to im­ple­ment change in smok­ing habits in this group of pa­tients.”

Newspapers in English

Newspapers from Australia

© PressReader. All rights reserved.