Cigarette smoking and white matter microstructure in schizophrenia

Area of Science:

• Neuroscience
• Psychiatry
• Radiology

Background:

• Schizophrenia is frequently comorbid with nicotine addiction.
• Both schizophrenia and nicotine use are associated with white matter microstructure alterations detected by diffusion tensor imaging (DTI).

Purpose of the Study:

• To investigate fractional anisotropy (FA) differences in brain white matter between smoking and non-smoking schizophrenia patients and healthy controls.
• To explore the influence of intellectual quotient (IQ) on these FA differences.

Main Methods:

• Diffusion tensor imaging (DTI) was performed on 43 schizophrenia patients (28 smoking, 15 non-smoking) and 40 healthy non-smoking controls.
• Fractional anisotropy (FA) was analyzed in global and regional regions of interest, with and without IQ as a covariate.

Main Results:

• Smoking schizophrenia patients showed lower FA in global, total cortical, frontal, and occipital regions compared to controls.
• Frontal lobe FA differences between smoking and non-smoking patients were significant without IQ correction but not after.
• FA was correlated with IQ in schizophrenia patients, but not in controls.

Conclusions:

• Smoking-related alterations in white matter microstructure (FA) in schizophrenia may be mediated by IQ.
• Low FA in specific brain regions could serve as a neural marker for schizophrenia, low IQ, and nicotine addiction.