In a double-blinded, randomized, parallel controlled design, patients with schizophrenia spectrum disorder will be exposed to active or sham repetitive transcranial magentic stimulation (TMS) which was guided by functional magnetic resonance image (MRI). Smoking reduction/cessation and brain functional connectivity changes will be assessed at baseline, different stages of rTMS and/or follow-ups.
Neuroimaging studies suggest that high rate of smoking in patients with schizophrenia may be due to an overlap of nicotine addiction related circuitries and schizophrenia related circuitries, such that schizophrenia impact some of the same circuitries that increase risks for severe nicotine addiction in general. Those identified overlapping circuitries have been linked to several key features of nicotine addiction and can be represented by resting state functional connectivities. Transcranial magnetic stimulation (TMS) provides a non-invasive means for altering brain electrical neural activity. TMS has been approved by FDA for treatment of depression. Other applications have not been approved but it has been used in a wide range of clinical research especially in neurology and psychiatry. There are preliminarily significant improvements in treatments of smoking cessation in schizophrenia using TMS with small samples, but those treatments are not robust in larger samples. The high inter-subject variability limits the efficacy of TMS treatment in schizophrenia patients. We aim to develop a TMS method targeting special brain circuits that are both smoking cessation and schizophrenia related. If the corresponding brain circuits were successfully modulated, the treatment efficacy will be significantly improved and schizophrenia patients will benefit from the TMS treatment of smoking cessation.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
DOUBLE
Enrollment
44
Multiple trains of active transcranial magnetic stimulation in a day, for multiple days.
Multiple trains of sham transcranial magnetic stimulation in a day, for multiple days.
University of Maryland, Baltimore
Baltimore, Maryland, United States
Cigarette Per Day
Cigarette per day (CPD) is measured to index smoking reduction and cessation. The change of CPD between baseline and end-of-treatment (1-month time point), 3-month follow up (4-month time point) and 6-month follow up (7-month time point) are reported. Negative values of the change of CPD indicate reductions in cigarette consumption.
Time frame: 7 months
Functional Magnetic Resonance Imaging (fMRI)
Resting-state functional connectivity (rsFC) obtained from fMRI is used to evaluate the TMS effect on smoking cessation. The strength of rsFC was first defined by correlation coefficient (r). Because the distribution of r values is highly skewed, z scores (normally distributed) were computed via fisher r-to-z transform. The z score central value (i.e., z score of 0) represents no relationship between the two brain regions. A positive (negative) z score indicates a positive (negative) association between the two brain regions. According to our pilot data determined from a separate study, stronger rsFC (i.e., larger positive z score) was related to less smoking severity. The changes of rsFC between baseline and end-of-treatment (1-month time point) and 3-month follow up (4-month time point) are reported. A positive (negative) value of rsFC change suggests the rsFC was enhanced (weakened) by the intervention. No fMRI data were collected at 6-month follow up (7-month time point).
Time frame: 4 months
Cotinine
Cotinine level is an objective index of smoking status. Higher level of cotinine indicates more nicotine consumption. The change of cotinine level between baseline and end-of-treatment (1-month time point) is reported. Cotinine data were not collected at 3-month follow up (4-month time point) or 6-month follow up (7-month time point).
Time frame: 1 month
End-expired Carbon Monoxide (CO)
End-expired CO measure is an instant measure of smoking status. Higher CO level indicates more nicotine consumption. The change of CO level between baseline and end-of-treatment (1-month time point) is reported. No CO data were collected at 3-month follow up (4-month time point) or 6-month follow up (7-month time point).
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Time frame: 1 month
Normalized Gamma Power of Auditory Static State Response (ASSR) From Electroencephalography (EEG)
EEG is used to evaluate the brain activities that are corresponding to the TMS. Auditory static state response (ASSR) at gamma frequency (i.e., 40 Hz) is obtained from the EEG recording. The gamma power of ASSR was normalized as the ratio between the power at 40 Hz (i.e., gamma power) and the power of its neighboring frequencies (i.e., 39 and 41 Hz). Increased normalized gamma ASSR is usually related to the improvement of psychosis symptoms. The change of ASSR between baseline and end-of-treatment (1-month time point) and 3-month follow up (4-month time point) are reported. No EEG data were collected at 6-month follow up (7-month time point).
Time frame: 4 months