Smokers could be more prone to schizophrenia, study finds

March 26, 2012, University of Zurich

Smoking alters the impact of a schizophrenia risk gene. Scientists from the universities of Zurich and Cologne demonstrate that healthy people who carry this risk gene and smoke process acoustic stimuli in a similarly deficient way as patients with schizophrenia. Furthermore, the impact is all the stronger the more the person smokes.

Schizophrenia has long been known to be hereditary. However, as a melting pot of disorders with different is concealed behind manifestations of , research has still not been able to identify the main gene responsible to this day.

In order to study the of schizophrenia, the frequency of particular risk genes between healthy and ill people has mostly been compared until now. Pharmacopyschologist Professor Boris Quednow from University Hospital of Psychiatry, Zurich, and Professor Georg Winterer's workgroup at the University of Cologne have now adopted a novel approach. Using (EEG), the scientists studied the processing of simple acoustic stimuli (a sequence of similar clicks). When processing a particular stimulus, healthy people suppress the processing of other stimuli that are irrelevant to the task at hand. Patients with schizophrenia exhibit deficits in this kind of stimulus filtering and thus their brains are probably inundated with too much information. As psychiatrically healthy people also filter stimuli with varying degrees of efficiency, individual stimulus processing can be associated with particular genes.

In a large-scale study involving over 1,800 healthy participants from the general population, Boris Quednow and Georg Winterer examined how far acoustic stimulus filtering is connected with a known risk gene for schizophrenia: the so-called "transcription factor 4" gene (TCF4). TCF4 is a protein that plays a key role in . As patients with schizophrenia often smoke, the scientists also studied the smoking habits of the .

The data collected shows that psychiatrically healthy carriers of the TCF4 gene also filter stimuli less effectively – like people who suffer from schizophrenia. It turned out that primarily smokers who carry the risk gene display a less effective filtering of acoustic impressions. This effect was all the more pronounced the more the people smoked. Non-smoking carriers of the risk gene, however, did not process stimuli much worse. "Smoking alters the impact of the TCF4 gene on acoustic stimulus filtering," says Boris Quednow, explaining this kind of gene-environment interaction. "Therefore, smoking might also increase the impact of particular genes on the risk of schizophrenia." The results could also be significant for predicting schizophrenic disorders and for new treatment approaches, says Quednow and concludes: "Smoking should also be considered as an important cofactor for the risk of schizophrenia in future studies." A combination of genetic (e.g. TCF4), electrophysiological ( filtering) and demographic (smoking) factors could help diagnose the disorder more rapidly or also define new, genetically more uniform patient subgroups.

Explore further: Understanding Schizophrenia

More information: Boris B. Quednow et al. Schizophrenia risk polymorphisms in the TCF4 gene interact with smoking in the modulation of auditory sensory gating. In: PNAS, March 26, 2012. DOI: 10.1073/pnas.1118051109

Related Stories

Understanding Schizophrenia

November 16, 2011
(Medical Xpress) -- Genetic mutations that cause schizophrenia could be linked to systems in the brain responsible for learning and memory, a major University study suggests.

Recommended for you

New study offers insights on genetic indicators of COPD risk

January 16, 2018
Researchers have discovered that genetic variations in the anatomy of the lungs could serve as indicators to help identify people who have low, but stable, lung function early in life, and those who are particularly at risk ...

Previous influenza virus exposures enhance susceptibility in another influenza pandemic

January 16, 2018
While past exposure to influenza A viruses often builds immunity to similar, and sometimes different, strains of the virus, Canadian researchers are calling for more attention to exceptions to that rule.

Don't hold your nose and close your mouth when you sneeze, doctors warn

January 15, 2018
Pinching your nose while clamping your mouth shut to contain a forceful sneeze isn't a good idea, warn doctors in the journal BMJ Case Reports.

New antifungal provides hope in fight against superbugs

January 12, 2018
Microscopic yeast have been wreaking havoc in hospitals around the world—creeping into catheters, ventilator tubes, and IV lines—and causing deadly invasive infection. One culprit species, Candida auris, is resistant ...

Dengue takes low and slow approach to replication

January 11, 2018
A new study reveals how dengue virus manages to reproduce itself in an infected person without triggering the body's normal defenses. Duke researchers report that dengue pulls off this hoax by co-opting a specialized structure ...

Different strains of same bacteria trigger widely varying immune responses

January 11, 2018
Genetic differences between different strains of the same pathogenic bacterial species appear to result in widely varying immune system responses, according to new research published in PLOS Pathogens.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.