Effects of rTMS on Cigarette Smoking and Cognition in Schizophrenia
Condition: Schizophrenia; Nicotine Addiction
MeSH terms: Tobacco Use Disorder; Schizophrenia
Study type: Interventional

Summary: 
      Cigarette smoking rates are extremely high in persons with schizophrenia and this increases
      the risk of disease and death due to tobacco-related disorders. One of the features of
      schizophrenia is reduced cognitive abilities, such as poor attention and memory. It is
      thought that people with schizophrenia smoke cigarettes to reduce these cognitive problems,
      as nicotine can improve cognitive function in these people. When people with schizophrenia
      stop smoking it causes further cognitive difficulties, which makes quitting harder for them
      compared to people without schizophrenia. A method called repetitive transcranial magnetic
      stimulation (rTMS) allows clinicians to give repeated magnetic pulses through the scalp to
      cause changes in brain activity and behaviour. rTMS can improve cognitive function in people
      with schizophrenia. Studies have also shown that rTMS can reduce tobacco craving and
      consumption of cigarettes. Therefore, we believe that rTMS will improve the cognitive
      deficits observed during cigarette smoking abstinence and help reduce cravings for
      cigarettes. Ultimately, rTMS may help smokers with schizophrenia who can't quit smoking with
      available treatments. This study will examine the effect of rTMS on tobacco cravings and
      cognitive problems produced by overnight abstinence from cigarette smoking in persons with
      schizophrenia in comparison to people without mental illness who smoke. Important information
      about the potential of rTMS for the treatment of cognitive deficits and tobacco addiction in
      schizophrenia will be obtained. Providing more effective smoking cessation treatments in
      people with schizophrenia may lead to improved physical and mental health for these patients,
      who are extremely susceptible to tobacco addiction and tobacco-related illness.
    


Intervention name(s): Repetitive Transcranial Magnetic Stimulation (rTMS); Sham Repetitive Transcranial Stimulation (rTMS)
Intervention type(s): Device; Device
Intervention description(s): Subjects will undergo two testing weeks (active and sham rTMS treatment), washout period ≥ 1 month between the testing weeks. rTMS treatment sessions will take place twice daily on days 1-3 of each test week. Active treatment will be delivered at 90% resting motor threshold intensity. Stimulation will be administered at 20 Hz with 25 stimulation trains of 30 stimuli each with an inter-train interval of 30 sec at equivalent stimulation parameters as those used in our pilot trial. Stimulation Site: Advanced neuronavigation methods will be used to target rTMS to the dorsolateral prefrontal cortex following a T1 weighted MRI scan.; Subjects will undergo two testing weeks (active and sham rTMS treatment) administered in a randomized order, to which both experimenter and participant will be blind. There will be a washout period of at least one month between the testing weeks to ensure that any changes in cortical function induced by rTMS have returned to baseline. rTMS treatment sessions will take place twice daily on days 1-3 of each test week. Sham Condition: A single-wing tilt rTMS coil position producing somatic sensation (contraction of scalp muscles) with minimal direct brain effects will be used (same stimulation parameters and site as active condition).
Other intervention name(s): Brain stimulation
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Basic Science
Keywords: Schizophrenia; Nicotine; Transcranial Magnetic Stimulation; Cognition; EEG