Effects of rTMS on Cigarette Smoking and Cognition in Schizophrenia

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.

Conditions

• Schizophrenia
• Nicotine Addiction

Interventions

DEVICE

Repetitive Transcranial Magnetic Stimulation (rTMS)

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.

DEVICE

Sham Repetitive Transcranial Stimulation (rTMS)

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).

Sponsors & Collaborators

• Canadian Institutes of Health Research (CIHR)

  collaborator OTHER_GOV

• Centre for Addiction and Mental Health

  lead OTHER

Principal Investigators

• Tony P George, M.D. · Centre for Addiction and Mental Health, Schizophrenia Program, Toronto, ON, Canada

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

QUADRUPLE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

55 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2012-04-30

Primary Completion

2015-09-30

Completion

2015-09-30

Countries

• Canada

Study Locations