Addiction is a leading cause of disability around the world and we are continuing to find ways to enhance treatment and recovery outcomes. Could brain stimulation techniques be the latest addition to our line-up of effective treatments?
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Addiction is a disease that affects the brain. As addiction progresses, drugs change the brain’s structure and the way it functions, and these observable changes lead to maladaptive behaviors like compulsive drug seeking and use despite negative consequences. Treatments for substance use disorder aim to heal the brain and change harmful behaviors. While many empirically-supported pharmacological and behavioral interventions are available for treating addiction, relapse is common and our pursuit to enhance current treatments and discover new ones continues. This review evaluates recent research assessing the therapeutic potential of brain stimulation techniques for treating substance use disorders.
The authors performed an extensive review on 60 studies, conducted between the years 2000 and 2017, that assessed the effects of brain stimulation on substance use disorder outcomes. The authors entered specific search terms into databases containing hundreds of thousands of scientific articles to find the studies that met their specific criteria to be included in this review. Studies meeting their criteria needed to assess one of three brain stimulation techniques.
Activating or suppressing activity in a specific brain site by holding a magnet (AKA electromagnetic coil) against the head near that site and sending short pulses of electrical current through the magnet, which painlessly pass through the forehead and stimulate brain cells in the desired area.
SOURCE: Bryan Christie Design
Activating or suppressing the activity of specific brain regions by sending a constant low-intensity current through two or more electrodes placed on the head. This painless and noninvasive technique is very similar to rTMS.
SOURCE: Valentin, L. S. S., Fregni, F., & Carmona, M. J. C. (2015). Effects of the Transcranial Direct Current Stimulation on Prevention of Postoperative Cognitive Dysfunction after Cardiac Surgery: Prospective, Randomized, Double-Blind Study. J Neurol Stroke, 3(1), 00078.
Unlike rTMS and tDCS, which are noninvasive, this technique requires brain surgery. Two small electrodes are placed on either side of a specific brain structure. These electrodes are attached via thin wires to battery-operated generators placed in the chest. Electrical pulses continuously pass from the generators to the electrodes in the brain, which stimulate brain cells in that specific area. This technique can continuously target specific structures deep within the brain and directly manipulate brain circuits associated with drug-related rewards.
The studies included in this review also needed to measure the effects of these brain stimulation techniques on specific outcomes including, substance use (e.g., reducing or stopping use after treatment) and craving (in general and/or during exposure to drug cues, for example, craving in response to viewing images of a beer bottle). All studies evaluated people diagnosed with a substance use disorder (drug or alcohol abuse / dependence based on the diagnostic and statistical manual of mental disorders, or DSM).
In general, investigation typically consisted of an active group, which received the brain stimulation treatment, and a sham group. The sham group believed they were receiving the treatment, but either no actual brain stimulation occurred, or stimulation was applied to a brain region that is thought to be unrelated to addiction processes (e.g., motor cortex). A sham condition helps researchers determine the effectiveness of the actual treatment, accounting for the possible effects of general study participation, including the belief that they will get better from the treatment, usually called a “placebo effect”.
rTMS (28 studies):
Investigations of rTMS show promising results for alcohol dependence, nicotine dependence, cocaine dependence, and methamphetamine dependence. In these studies rTMS generally had a large effect on craving and/or substance use, with rTMS patients showing reduced craving and consumption relative to sham treated patients or their own pre-treatment measures (craving and use before rTMS). However, these positive treatment effects were largely specific to studies that administered multiple rTMS treatments. Studies implementing a single treatment had less successful outcomes. Stimulating frontal brain regions, particularly the right dorsolateral prefrontal cortex (plays an important role in reward processing, motivation, and behavioral control), also seems to produce the best outcomes. Only one study assessed rTMS for cannabis use disorder, which showed no effect of rTMS on craving. None of the rTMS studies included in this review addressed opioid use disorder.
tDCS (23 studies):
Fewer tDCS studies have been conducted. Among them, tDCS is shown to reduce alcohol, nicotine, and cocaine craving and/or consumption compared to sham treatment and pre-treatment measures. Similar to rTMS, positive tDCS treatment effects are generally observed when the right dorsolateral prefrontal cortex is stimulated and when individuals receive multiple treatment episodes, but the size of this effect on craving and consumption is less consistent across tDCS studies, ranging from small to large. Treatment sessions lasting longer than 10 minutes also seemed to be more effective. The effects of tDCS in individuals with methamphetamine, opioid, and cannabis use disorders have each been evaluated in only one study. Although each of these studies show promise for tDCS as a potential treatment across these three substance use disorders, it is too early to make conclusions about its therapeutic effects.
DBS (9 studies):
Interestingly, all DBS studies revealed positive results, with DBS in the nucleus accumbens (a structure deep in the center of the brain, also associated with processing drug-related rewards) decreasing craving and/or consumption of alcohol, tobacco, cocaine, and opioids. However, given that surgery is required for this procedure, available data are limited to small sample sizes that range from one to ten participants and many studies are based on a single participant (i.e. case studies).
This review highlights the potential for brain stimulation techniques to help treat a variety of substance use disorders. More research is needed to fine-tune these techniques, better understand their mechanisms of action, and make formal conclusions about their effectiveness. Still, they pose an intriguing potential treatment option for those who have not had much success with standard treatments and seek alternative therapies. Given the noninvasive nature and relatively low cost of rTMS and tDCS, exploring their potential therapeutic benefits for treating substance use disorders is certainly worthwhile. Despite the invasive procedures needed for administering DBS, it could ultimately prove to be a potential option for those suffering from more severe substance use disorders who have tried all other treatment options to no avail.
Although these brain stimulation techniques seem to produce positive outcomes in the short-term, this review also underscores the need for further investigation before they can be implemented clinically. Importantly, the long-term effects of brain stimulation are not yet clear. Exceptionally few studies have followed patients over time to see how long these treatment benefits last. To date, sham-controlled studies have found both positive and negative long-term outcomes (e.g., 6 months, 1 year) after brain stimulation treatments, with higher relapse rates and improved abstinence rates observed in actively treated patients compared to sham treated patients. However, the effects of brain stimulation beyond the first few weeks or months are vastly understudied. Prospective research can help us identify what these long-term effects are, and whether or not it has important implications for addiction treatment.
Coles, A. S., Kozak, K., & George, T. P. (2018). A review of brain stimulation methods to treat substance use disorders. The American journal on addictions, 27(2), 71-91.
l
Addiction is a disease that affects the brain. As addiction progresses, drugs change the brain’s structure and the way it functions, and these observable changes lead to maladaptive behaviors like compulsive drug seeking and use despite negative consequences. Treatments for substance use disorder aim to heal the brain and change harmful behaviors. While many empirically-supported pharmacological and behavioral interventions are available for treating addiction, relapse is common and our pursuit to enhance current treatments and discover new ones continues. This review evaluates recent research assessing the therapeutic potential of brain stimulation techniques for treating substance use disorders.
The authors performed an extensive review on 60 studies, conducted between the years 2000 and 2017, that assessed the effects of brain stimulation on substance use disorder outcomes. The authors entered specific search terms into databases containing hundreds of thousands of scientific articles to find the studies that met their specific criteria to be included in this review. Studies meeting their criteria needed to assess one of three brain stimulation techniques.
Activating or suppressing activity in a specific brain site by holding a magnet (AKA electromagnetic coil) against the head near that site and sending short pulses of electrical current through the magnet, which painlessly pass through the forehead and stimulate brain cells in the desired area.
SOURCE: Bryan Christie Design
Activating or suppressing the activity of specific brain regions by sending a constant low-intensity current through two or more electrodes placed on the head. This painless and noninvasive technique is very similar to rTMS.
SOURCE: Valentin, L. S. S., Fregni, F., & Carmona, M. J. C. (2015). Effects of the Transcranial Direct Current Stimulation on Prevention of Postoperative Cognitive Dysfunction after Cardiac Surgery: Prospective, Randomized, Double-Blind Study. J Neurol Stroke, 3(1), 00078.
Unlike rTMS and tDCS, which are noninvasive, this technique requires brain surgery. Two small electrodes are placed on either side of a specific brain structure. These electrodes are attached via thin wires to battery-operated generators placed in the chest. Electrical pulses continuously pass from the generators to the electrodes in the brain, which stimulate brain cells in that specific area. This technique can continuously target specific structures deep within the brain and directly manipulate brain circuits associated with drug-related rewards.
The studies included in this review also needed to measure the effects of these brain stimulation techniques on specific outcomes including, substance use (e.g., reducing or stopping use after treatment) and craving (in general and/or during exposure to drug cues, for example, craving in response to viewing images of a beer bottle). All studies evaluated people diagnosed with a substance use disorder (drug or alcohol abuse / dependence based on the diagnostic and statistical manual of mental disorders, or DSM).
In general, investigation typically consisted of an active group, which received the brain stimulation treatment, and a sham group. The sham group believed they were receiving the treatment, but either no actual brain stimulation occurred, or stimulation was applied to a brain region that is thought to be unrelated to addiction processes (e.g., motor cortex). A sham condition helps researchers determine the effectiveness of the actual treatment, accounting for the possible effects of general study participation, including the belief that they will get better from the treatment, usually called a “placebo effect”.
rTMS (28 studies):
Investigations of rTMS show promising results for alcohol dependence, nicotine dependence, cocaine dependence, and methamphetamine dependence. In these studies rTMS generally had a large effect on craving and/or substance use, with rTMS patients showing reduced craving and consumption relative to sham treated patients or their own pre-treatment measures (craving and use before rTMS). However, these positive treatment effects were largely specific to studies that administered multiple rTMS treatments. Studies implementing a single treatment had less successful outcomes. Stimulating frontal brain regions, particularly the right dorsolateral prefrontal cortex (plays an important role in reward processing, motivation, and behavioral control), also seems to produce the best outcomes. Only one study assessed rTMS for cannabis use disorder, which showed no effect of rTMS on craving. None of the rTMS studies included in this review addressed opioid use disorder.
tDCS (23 studies):
Fewer tDCS studies have been conducted. Among them, tDCS is shown to reduce alcohol, nicotine, and cocaine craving and/or consumption compared to sham treatment and pre-treatment measures. Similar to rTMS, positive tDCS treatment effects are generally observed when the right dorsolateral prefrontal cortex is stimulated and when individuals receive multiple treatment episodes, but the size of this effect on craving and consumption is less consistent across tDCS studies, ranging from small to large. Treatment sessions lasting longer than 10 minutes also seemed to be more effective. The effects of tDCS in individuals with methamphetamine, opioid, and cannabis use disorders have each been evaluated in only one study. Although each of these studies show promise for tDCS as a potential treatment across these three substance use disorders, it is too early to make conclusions about its therapeutic effects.
DBS (9 studies):
Interestingly, all DBS studies revealed positive results, with DBS in the nucleus accumbens (a structure deep in the center of the brain, also associated with processing drug-related rewards) decreasing craving and/or consumption of alcohol, tobacco, cocaine, and opioids. However, given that surgery is required for this procedure, available data are limited to small sample sizes that range from one to ten participants and many studies are based on a single participant (i.e. case studies).
This review highlights the potential for brain stimulation techniques to help treat a variety of substance use disorders. More research is needed to fine-tune these techniques, better understand their mechanisms of action, and make formal conclusions about their effectiveness. Still, they pose an intriguing potential treatment option for those who have not had much success with standard treatments and seek alternative therapies. Given the noninvasive nature and relatively low cost of rTMS and tDCS, exploring their potential therapeutic benefits for treating substance use disorders is certainly worthwhile. Despite the invasive procedures needed for administering DBS, it could ultimately prove to be a potential option for those suffering from more severe substance use disorders who have tried all other treatment options to no avail.
Although these brain stimulation techniques seem to produce positive outcomes in the short-term, this review also underscores the need for further investigation before they can be implemented clinically. Importantly, the long-term effects of brain stimulation are not yet clear. Exceptionally few studies have followed patients over time to see how long these treatment benefits last. To date, sham-controlled studies have found both positive and negative long-term outcomes (e.g., 6 months, 1 year) after brain stimulation treatments, with higher relapse rates and improved abstinence rates observed in actively treated patients compared to sham treated patients. However, the effects of brain stimulation beyond the first few weeks or months are vastly understudied. Prospective research can help us identify what these long-term effects are, and whether or not it has important implications for addiction treatment.
Coles, A. S., Kozak, K., & George, T. P. (2018). A review of brain stimulation methods to treat substance use disorders. The American journal on addictions, 27(2), 71-91.
l
Addiction is a disease that affects the brain. As addiction progresses, drugs change the brain’s structure and the way it functions, and these observable changes lead to maladaptive behaviors like compulsive drug seeking and use despite negative consequences. Treatments for substance use disorder aim to heal the brain and change harmful behaviors. While many empirically-supported pharmacological and behavioral interventions are available for treating addiction, relapse is common and our pursuit to enhance current treatments and discover new ones continues. This review evaluates recent research assessing the therapeutic potential of brain stimulation techniques for treating substance use disorders.
The authors performed an extensive review on 60 studies, conducted between the years 2000 and 2017, that assessed the effects of brain stimulation on substance use disorder outcomes. The authors entered specific search terms into databases containing hundreds of thousands of scientific articles to find the studies that met their specific criteria to be included in this review. Studies meeting their criteria needed to assess one of three brain stimulation techniques.
Activating or suppressing activity in a specific brain site by holding a magnet (AKA electromagnetic coil) against the head near that site and sending short pulses of electrical current through the magnet, which painlessly pass through the forehead and stimulate brain cells in the desired area.
SOURCE: Bryan Christie Design
Activating or suppressing the activity of specific brain regions by sending a constant low-intensity current through two or more electrodes placed on the head. This painless and noninvasive technique is very similar to rTMS.
SOURCE: Valentin, L. S. S., Fregni, F., & Carmona, M. J. C. (2015). Effects of the Transcranial Direct Current Stimulation on Prevention of Postoperative Cognitive Dysfunction after Cardiac Surgery: Prospective, Randomized, Double-Blind Study. J Neurol Stroke, 3(1), 00078.
Unlike rTMS and tDCS, which are noninvasive, this technique requires brain surgery. Two small electrodes are placed on either side of a specific brain structure. These electrodes are attached via thin wires to battery-operated generators placed in the chest. Electrical pulses continuously pass from the generators to the electrodes in the brain, which stimulate brain cells in that specific area. This technique can continuously target specific structures deep within the brain and directly manipulate brain circuits associated with drug-related rewards.
The studies included in this review also needed to measure the effects of these brain stimulation techniques on specific outcomes including, substance use (e.g., reducing or stopping use after treatment) and craving (in general and/or during exposure to drug cues, for example, craving in response to viewing images of a beer bottle). All studies evaluated people diagnosed with a substance use disorder (drug or alcohol abuse / dependence based on the diagnostic and statistical manual of mental disorders, or DSM).
In general, investigation typically consisted of an active group, which received the brain stimulation treatment, and a sham group. The sham group believed they were receiving the treatment, but either no actual brain stimulation occurred, or stimulation was applied to a brain region that is thought to be unrelated to addiction processes (e.g., motor cortex). A sham condition helps researchers determine the effectiveness of the actual treatment, accounting for the possible effects of general study participation, including the belief that they will get better from the treatment, usually called a “placebo effect”.
rTMS (28 studies):
Investigations of rTMS show promising results for alcohol dependence, nicotine dependence, cocaine dependence, and methamphetamine dependence. In these studies rTMS generally had a large effect on craving and/or substance use, with rTMS patients showing reduced craving and consumption relative to sham treated patients or their own pre-treatment measures (craving and use before rTMS). However, these positive treatment effects were largely specific to studies that administered multiple rTMS treatments. Studies implementing a single treatment had less successful outcomes. Stimulating frontal brain regions, particularly the right dorsolateral prefrontal cortex (plays an important role in reward processing, motivation, and behavioral control), also seems to produce the best outcomes. Only one study assessed rTMS for cannabis use disorder, which showed no effect of rTMS on craving. None of the rTMS studies included in this review addressed opioid use disorder.
tDCS (23 studies):
Fewer tDCS studies have been conducted. Among them, tDCS is shown to reduce alcohol, nicotine, and cocaine craving and/or consumption compared to sham treatment and pre-treatment measures. Similar to rTMS, positive tDCS treatment effects are generally observed when the right dorsolateral prefrontal cortex is stimulated and when individuals receive multiple treatment episodes, but the size of this effect on craving and consumption is less consistent across tDCS studies, ranging from small to large. Treatment sessions lasting longer than 10 minutes also seemed to be more effective. The effects of tDCS in individuals with methamphetamine, opioid, and cannabis use disorders have each been evaluated in only one study. Although each of these studies show promise for tDCS as a potential treatment across these three substance use disorders, it is too early to make conclusions about its therapeutic effects.
DBS (9 studies):
Interestingly, all DBS studies revealed positive results, with DBS in the nucleus accumbens (a structure deep in the center of the brain, also associated with processing drug-related rewards) decreasing craving and/or consumption of alcohol, tobacco, cocaine, and opioids. However, given that surgery is required for this procedure, available data are limited to small sample sizes that range from one to ten participants and many studies are based on a single participant (i.e. case studies).
This review highlights the potential for brain stimulation techniques to help treat a variety of substance use disorders. More research is needed to fine-tune these techniques, better understand their mechanisms of action, and make formal conclusions about their effectiveness. Still, they pose an intriguing potential treatment option for those who have not had much success with standard treatments and seek alternative therapies. Given the noninvasive nature and relatively low cost of rTMS and tDCS, exploring their potential therapeutic benefits for treating substance use disorders is certainly worthwhile. Despite the invasive procedures needed for administering DBS, it could ultimately prove to be a potential option for those suffering from more severe substance use disorders who have tried all other treatment options to no avail.
Although these brain stimulation techniques seem to produce positive outcomes in the short-term, this review also underscores the need for further investigation before they can be implemented clinically. Importantly, the long-term effects of brain stimulation are not yet clear. Exceptionally few studies have followed patients over time to see how long these treatment benefits last. To date, sham-controlled studies have found both positive and negative long-term outcomes (e.g., 6 months, 1 year) after brain stimulation treatments, with higher relapse rates and improved abstinence rates observed in actively treated patients compared to sham treated patients. However, the effects of brain stimulation beyond the first few weeks or months are vastly understudied. Prospective research can help us identify what these long-term effects are, and whether or not it has important implications for addiction treatment.
Coles, A. S., Kozak, K., & George, T. P. (2018). A review of brain stimulation methods to treat substance use disorders. The American journal on addictions, 27(2), 71-91.
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