Cigarette smoking normalizes deficits in sensorimotor gating in schizophrenia

[David Baxter PhD]

Cigarette smoking normalizes deficits in sensorimotor gating in schizophrenia
By Ingrid Grasmo
30 June 2009
Schizophr Res 2009; 112: 86?90

Study results show that cigarette smoking has a positive effect on sensorimotor gating in patients with schizophrenia, improving the prepulse inhibition (PPI) deficit of the startle response to levels comparable to those seen in healthy individuals.

?These findings have significant implications for understanding vulnerability to tobacco dependence in schizophrenia, which may lead to the development of more effective treatments for PPI deficits and tobacco dependence in this population,? write Tony George (University of Toronto, Ontario, Canada) and co-authors in the journal Schizophrenia Research.

The authors studied PPI of the startle response as a function of smoking status and schizophrenia diagnosis in smokers with schizophrenia (n=14), non-smokers with schizophrenia (n=15), control smokers (n=11), and control non-smokers (n=10).

The authors found the smokers with schizophrenia had comparable levels of PPI ? as seen by significant differences in the peak onset ? to control smokers and non-smokers (33.0, 28.5, and 39.1 ms, respectively). Significantly higher levels of PPI were seen in smokers with schizophrenia than schizophrenia nonsmokers (peak onset = 33.0 vs 14.3 ms).

Furthermore, at all prepulse to pulse intervals (30, 60, and 120 ms), non-smokers with schizophrenia had an approximate 50% reduction in PPI compared with control non-smokers.

The study results therefore suggest that acute smoking to produce smoking satiation is associated with apparent normalization of PPI deficits in patients with schizophrenia.

A previous study conducted by George et al demonstrated that acute smoking deprivation was associated with a reduction in PPI in schizophrenia patients, and that acute smoking improved PPI.

The team says that taken together, both study results suggest that ?cigarette smoking has a positive effect on PPI deficits in patients with schizophrenia, and that there is a selectivity to this effect since PPI was not altered in smoking versus non-smoking control patients.?

They add: ?Further studies of the interactive effects of smoking and schizophrenia diagnosis on PPI and other sensory gating measures are clearly warranted and could provide important information towards developing novel therapeutics for neurocognitive dysfunction in schizophrenia based on central nicotinic acetylcholine receptor systems.?

Abstract

 

[Always Changing]

sensorimotor gating,

improving the prepulse inhibition (PPI)

can someone explain what these mean?

 

[David Baxter PhD]

sensorimotor gating
A behavioural trait in humans and animals that reflects the ability to filter out extraneous stimuli and to process information that comes in rapid succession.
Source: Reviews glossary

Prepulse inhibition
[T]he process whereby a relatively mild stimulus -- the prepulse -- acts through CNS synapses to suppress the response to a strong, startle-eliciting stimulus when the prepulse precedes the startle stimulus by a brief duration (in mammals, about 10 to 500 milliseconds).
Source: NEUROBIOLOGY: ON SENSORIMOTOR GATING

 

[Always Changing]

thank you david,,

So smoking by people with schizophrenia is good? if that is what positive means in this article, can the same be said then for other disorders? Bipolar for inst?
just curious.

 

[David Baxter PhD]

I'm not sure I'd go as far as to say that smoking is good. Therec are still the concerns about cancer, heart disease, lung diseaqse, etc., etc.

What's of interest about this article is that it may help us to understand what happens in schizophrenia and why individuals with schizophrenia seem to have such a high propensity for smoking (nicotine).

 

[Always Changing]

maybe we will see a type of nicotine patch as an added med for some peope with schizophrenia and related conditions.

As a smoker I can say that smoking does relieve some anxiety symptoms for me but do understand the risks as you have outlined above. Smoking is highly addictive and I am not in any way advocating anyone take up smoking.
maybe I should have claried my previous post by saying those patients who already smoke.

 

[Pheonix]

That is some very interesting info. I used to smoke for years (packed up 10 years ago thankfully). I used to binge smoke, (not smoke for days or weeks then smoke a pack of 20 with beer when I went out to socialize in the pub). Somehow it help me concentrate on conversations and the beer made me relax as I was shy. Then next day I would feel awful with nicotine toxicity. I am a highly creative painter and had a schizotypal diagnosis. Now its more of a mood disorder. But I never believed I was schizophrenic. I read that artists share the sensory motor gating thing with schizophrenics. I have that, sometimes I am too overloaded with stuff going on around me (traffic, horns, bright surfaces, planes taking off) its painful. I don't think its a disorder as such because in the countryside I open up my senses and breathe and see every lizard, quivering leaf, bird in the sky and goats on far hill all at once and it does not bother me at all. Its interesting how man made made simulations are overloading and natural ones are coped with, even an advantage, say in hunting for food.