Non-invasive brain stimulation reduced cigarette cravings among smokers with schizophrenia, according to a preliminary study at the Centre for Addiction and Mental Health (CAMH).
People with schizophrenia have smoking rates that are three to four times higher than the general population. One of the complex reasons is that they may get some benefits from the nicotine in cigarettes to their cognitive functioning – their memory, thinking and perceptions. Some studies also suggest smokers with schizophrenia crave cigarettes more than other smokers. These factors may contribute to the low rates of quitting seen in these individuals, and high rates of tobacco-related death and disability.
Repetitive transcranial magnetic stimulation (rTMS), a non-invasive approach, may help in two ways, which prompted clinical scientists from CAMH’s Schizophrenia Program to conduct this study.
Past CAMH research has shown that rTMS improves a person’s cognitive functioning. rTMS may replace the cognitive benefits of smoking, and enable smokers to have more control over their cravings. CAMH’s Research Imaging Centre has also shown that rTMS causes the release of dopamine, a neurotransmitter important in addictions, in the same way as nicotine.
But there have been few studies in this area, and none among smokers with schizophrenia, note researchers Drs. Tony George, Victoria Wing and Jeff Daskalakis, whose study was recently published in Schizophrenia Research.
Six study participants were randomly assigned to receive rTMS, while nine received a sham treatment to serve as a control group. All participants had five sessions of either rTMS or sham treatment per week for four weeks.
After one week, rTMS significantly reduced cravings in smokers compared with the control group, according to craving measures that were taken before and after treatment. Although the numbers are small, the findings warrant further investigation of rTMS as a potential addition to smoking cessation treatments, the researchers say.
It’s not known exactly how rTMS affects cravings or how long the effect will last. Further work is underway in this collaborative research between CAMH’s Biobehavioural Addictions and Concurrent Disorders Research Lab and Brain Stimulation Treatment and Research Unit.
The researchers are aiming to identify the specific effects of rTMS in smokers with and without schizophrenia in a three-year laboratory-based study, which is being funded by the Canadian Institutes of Health Research (CIHR), to prepare for a larger treatment trial of rTMS in smokers with schizophrenia.