Effects of cigarette smoking on cortical thickness in major depressive disorder.
Findings of surface-based morphometry studies in major depressive disorder (MDD) are still inconsistent. Given that cigarette smoking is highly prevalent in MDD and has documented negative effects on the brain, it is possible that some of the inconsistencies may be partly explained by cigarette use. The aim of the current study was to examine the influence of cigarette smoking on brain structure in MDD. 50 MDD patients (25 smokers and 25 non-smokers) and 22 age, education, gender and BMI matched non-smoker healthy controls underwent structural magnetic resonance imaging. Thickness and area of the cortex were measured using surface-based morphometry implemented with Freesurfer (v5.3.0). The non-smoker MDD patients had significantly increased cortical thickness, including in the left temporal cortex (p < 0.001), right insular cortex (p = 0.033) and left pre- and postcentral gyrus (p = 0.045), compared to healthy controls. We also found decreased cortical thickness in MDD patients who smoked compared to non-smoking patients in regions that overlapped with the regions found to be increased in non-smoking patients in comparison to controls. Non-smoker MDD patients had increased surface area in the right lateral occipital cortex (p = 0.009). We did not find any region where cortical thickness or surface area significantly differed between controls and either smoker MDD patients or all MDD patients. The findings of the current study suggest that cigarette smoking is associated with cortical thinning in regions found to be increased in patients with MDD. However, these results should be considered preliminary due to methodological limitations.
Department of Psychiatry, Katip Celebi University, Ataturk Training and Research Hospital, Izmir, Turkey. Electronic address: zorlunabi@hotmail.com.
Nabi
N
Zorlu
Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia; Faculty of Health, Arts and Design, Swinburne University of Technology, Hawthorn, Australia.
Vanessa Louise
VL
Cropley
Department of Psychiatry, Izmir Bozyaka Training and Research Hospital, Izmir, Turkey.
Pelin Kurtgoz
PK
Zorlu
Department of Psychiatry, Izmir Bozyaka Training and Research Hospital, Izmir, Turkey.
Dursun Hakan
DH
Delibas
Department of Radiology, Izmir Bozyaka Training and Research Hospital, Izmir, Turkey.
Zehra Hilal
ZH
Adibelli
Department of Psychiatry, Izmir Bozyaka Training and Research Hospital, Izmir, Turkey.
Emel Pasa
EP
Baskin
Department of Radiology, Izmir Bozyaka Training and Research Hospital, Izmir, Turkey.
Özgür Sipahi
ÖS
Esen
Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia.
Emre
E
Bora
Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia; Centre for Neural Engineering (CfNE), Department of Electrical and Electronic Engineering, University of Melbourne, Carlton South, VIC, Australia; Florey Institute for Neuroscience & Mental Health, Parkville, VIC, Australia.
Christos
C
Pantelis
D000293:Adolescent; D000328:Adult; D002540:Cerebral Cortex / Q000000981:diagnostic imaging*; D003865:Major Depressive Disorder / Q000150:complications* / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011569:Psychiatric Status Rating Scales; D012907:Smoking; D014029:Tobacco Use Disorder / Q000150:complications* / Q000000981:diagnostic imaging*; D055815:Young Adult
Cigarette smoking; Cortical thickness; Major depressive disorder; Structural imaging