Smokers and schizophrenia

Research shows that 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 stimuli in a similar way as those who have schizophrenia. The impact is also stronger the more the person smokes.

Schizophrenia is hereditary. Still, research hasn’t been able to pinpoint the gene responsible.

Pharmacopyschologist Professor Boris Quednow from University Hospital of Psychiatry, Zurich, and Professor Georg Winterer’s group from University of Cologne have developed a new approach to find that gene. Using electroencephalography (EEG) they studied the processing of a simple acoustic stimuli (clicking sounds). When processing the sound, healthy people suppress the processing other stimuli that are irrelevant to that task. Patients with schizophrenia exhibit deficits in this kind of filtering and therefore their brains are overwhelmed with too much information. As psychiatrically healthy people filter the stimuli, individual stimulus processing can be associated with particular genes.

Quednow and Winterer examined how far acoustic stimulus filtering is connected with a known risk gene called “transcription factor 4” or TCF4. TCF4 is a protein that plays a role in early brain development. Since many schizophrenic patients smoke, the scientists studied their smoking habits.

The data showed that healthy people with carriers of the TCF4 gene also filter stimuli less effectively – similar to those with schizophrenia. They then found that primarily smokers with TCF4 had this problem. “Smoking alters the impact of the TCF4 gene on acoustic stimulus filtering,” explained Quednow. “Therefore smoking might also incrase the impact of particular genes on the risk of schizophrenia.”

The results of the study could be important for predicting schizophrenic disorders.

Source: ScienceDaily, University of Zurich

photo by John Nyboer