Can brain electrostimulation replace antidepressants and help with stress?
Over the past year, research on non-invasive brain electrical stimulation has advanced far ahead. Thus, a large-scale analytical study based on 1,412 scientific articles revealed that the effect on the brain by weak direct current (tDCS) is effective for the treatment of depression and several other mental illnesses.
And, apparently, tDCS is not inferior in effectiveness to standard antidepressants, and in terms of safety, it also significantly outperforms them. Interestingly, similar electrostimulation can be used by healthy people to improve their mood and greater resistance to everyday stress.
Considering that in developed countries up to 17% of people at least once in their lives suffer from depression (as, for example, in the USA), and a decrease in mood as a result of depression entails various cognitive disorders: from memory problems to impaired ability to solve problems, then scientists suggest the widest potential application of the new technology.
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Brain electrical stimulation (tDCS) is the effect on the cerebral cortex with a weak direct current through electrodes located in certain areas of the head. Such an effect changes the physiological state of neurons, making them more or, conversely, less prone to stimulation. Depending on the location of the electrodes, such stimulation leads to a variety of effects : from alleviating chronic pain and treating mental illness in patients to accelerating learning and improving concentration in healthy people.
To date, more than 15,000 scientific experiments on humans have been conducted on the effects of tDCS on literally everything from schizophrenia to tinnitus treatment. However, the trouble of research is their strong heterogeneity: different exposure parameters (stimulation time, current strength, etc.) and different research quality - from good double-blind, placebo-controlled - to works in which there is not even a placebo group. Attempts to synthesize current knowledge of tDCS have already been made , but they have sinned by taking the analysis with different designs and sample sizes.
A large-scale study of a large team of neuroscientists from France, Germany, Switzerland, New Zealand, Italy and Belgium is perhaps the first example of a qualitative understanding of the influence of tDCS on various diseases. How tDCS can improve the cognitive functions of healthy people is the subject of a separate discussion previously covered .
Scientists analyzed a huge array of tDCS studies: no more, no less than 1,412 articles, in which more than 8,000 people participated, and selected works with only high-quality design among them.
The experiments were supposed to be with a control group of people (whose stimulation was imitated to exclude the placebo effect), as well as randomized ones (that is, subjects were randomly divided into groups). In all studies, people had to undergo not one tDCS session (which may not be enough for the effect), but several. In addition, higher priority was given to studies in which more than 25 people took part, and studies in which there were less than 10 participants were not taken into account at all.
Analysis of these studies has shown that tDCS is effective for treating several common diseases: depression, chronic pain, and addictions (for example, for alcohol, nicotine, and even soft drugs), but it does not help with chronic tinnitus. Based on these studies, scientists concluded that electrostimulation is effective in the case of those diseases where restructuring of the brain is not required.
The principle of operation of tDCS is not too complicated. Electrodes applied to the scalp affect the brain with a weak direct current (1-2 milliamperes). A positively charged electrode (“anode”) reduces the potential difference across the neuron membrane, which facilitates their excitation in the event of signals from neighboring neurons. A negatively charged electrode (“cathode”), on the contrary, increases the potential difference, reducing the excitability of neurons.
The result of a few minutes of electrical stimulation is an increase in the activity of the cerebral cortex under the anode, which lasts an hour or more after the procedure is completed. In the case of conducting tDCS for several days in a row, changes in interneuronal contacts , synapses, occur in the cortex neurons. For example, they may increase in size, which facilitates the transmission of a signal from one neuron to another. This process is called synaptic plasticity, and it is he who is responsible for preserving the effects of tDCS after completion of the course of effects.
The principle on which treatment of depression with tDCS is based is also quite simple. Studies show that depressed patients differ in the activity of certain areas of the frontal lobes of the cortex of the left and right hemispheres. Electrical stimulation is designed to compensate for this imbalance. To do this, over the less active brain area have a positively charged electrode ("anode"), which slightly increases its activity.
The analysis showed that electrostimulation of 20-30 minutes a day for at least several days in a row leads to a steady improvement in the condition of patients with severe, clinical form of depression. For this, correct positioning of the electrodes is crucial. The anode should be located above the left prefrontal cortex (DLPFC) - F3, and the cathode - on the right supraorbital region - FP2. Interestingly, if you move the cathode a few inches higher - the effect disappears.
Scientists assigned this conclusion “Class B”, that is, “technology is likely to be effective” and believe that in order to recognize electrostimulation as uniquely effective, research should be conducted with a large number of participants. However, transcranial electrostimulation has already been approved for the treatment of depression in Europe .
Interestingly, a direct comparison of tDCS and some antidepressants shows that electrical stimulation is not inferior to them in terms of effectiveness. For example, a double-blind, randomized study by scientists from Harvard demonstrated that after tDCS, patients with depression recovered faster than after taking fluoxitin, a selective serotonin reuptake inhibitor.
Another study showed that tDCS is not inferior to sertraline, another popular anti-depressant. It is important to note that in the case of a combination of both effects (electrical stimulation with an antidepressant) - the effect was superior to each of the therapies separately.
However, if the efficacy of tDCS and antidepressants (at least some) is similar, in terms of safety, electrical stimulation significantly outpaces them. Indeed, the side effects of antidepressants can be quite serious (up to obesity, sexual problems and even hallucinations).
Side effects at tDCS are much less significant. Although they were closely monitored in each of the studies, among the undesirable consequences for patients, periodically, there was only a slight tingling and burning sensation, as well as skin irritation in the areas of electrode attachment.
However, today the tDCS technology has one major drawback. For treatment, patients are forced to go to the clinic for procedures (unlike antidepressants, which can be taken at home on their own).
That is why several companies set about developing portable medical devices for home use. These are, for example, the New York company Soterix Medical and the Korean startup Ybrain . In addition, several non-medical tDCS devices are already being produced, offering the same arrangement of electrodes for depression under the sign of "improving mood".
Andre Bruoni, a neuroscientist and psychiatrist at the University of SĂŁo Paulo, believes that such devices have 3 potential advantages:
- Price: Since tDCS devices are relatively cheap, people will prefer technology over transcranial magnetic stimulation (TMS) over them.
- Ease of use: Brouoni says that startups like Soterix "are developing very safe and reliable devices for home use with almost zero risk."
- Short treatment: tDCS therapy for depression will begin with an intensive course - for example, 2 weeks of daily electrostimulation sessions - after which much rarer sessions will be held to maintain the effect. This is a great advantage over antidepressants, which often require courses from 9 months (during which they can cause negative side effects).
Interestingly, electrical stimulation from depression (“anode” - on the left dorsolateral prefrontal cortex) can be useful for healthy people. For example, in 2016, a double-blind, placebo-controlled study on 66 healthy volunteers showed that electrical stimulation significantly improved the general mood of the subjects, including reduced anxiety, depression, hostility to others, reduced fatigue and a sense of confusion.
Another study of the same year, conducted by Oxford scientists on 60 healthy people, showed that tDCS increases a person’s resistance to stress.
Against the background of the constant increase in the number of such studies, a rather large community of people who use tDCS in their daily lives has been formed. On the Reddit site alone, more than 8,000 people are constantly sharing their experiences using tDCS devices, while about 30% tried using technology to treat depression (other users use tDCS to improve memory, concentration and concentration).
For procedures, people use special non-medical devices - designed for everyday use, which are already being released in the USA - Thebrainstimulator , Hong Kong - Priormind and since last year - in Russia - Brainstorm neurostimulator . All of them allow the electrodes to be placed on several (up to 10) different zones of the head, for different cognitive effects, among which there is an improvement in mood.
It is a curious fact that in the first non-medical tDCS device, manufactured by the American company foc.us and intended to improve the reaction and concentration of attention of gamers, the electrodes were located precisely to improve mood (from depression):
It is possible that this is why such a device was popular: although it did not directly affect the reaction and memory, it improved the mood and due to this the users liked it. However, foc.us subsequently corrected its mistake and the similar device is no longer produced.
Many scientists, however, are wary of the independent use of tDCS, which is fraught with many inadvertent errors (for example, improper placement of electrodes on the head or too long an exposure time - instead of 20-30 minutes), which can lead to undesirable results. But on the other hand, scientists themselves are now proposing that people use tDCS at home as part of scientific experiments, when they are convinced that people fully comply with safety precautions.
And, apparently, tDCS is not inferior in effectiveness to standard antidepressants, and in terms of safety, it also significantly outperforms them. Interestingly, similar electrostimulation can be used by healthy people to improve their mood and greater resistance to everyday stress.
Considering that in developed countries up to 17% of people at least once in their lives suffer from depression (as, for example, in the USA), and a decrease in mood as a result of depression entails various cognitive disorders: from memory problems to impaired ability to solve problems, then scientists suggest the widest potential application of the new technology.
')
Brain electrical stimulation (tDCS) is the effect on the cerebral cortex with a weak direct current through electrodes located in certain areas of the head. Such an effect changes the physiological state of neurons, making them more or, conversely, less prone to stimulation. Depending on the location of the electrodes, such stimulation leads to a variety of effects : from alleviating chronic pain and treating mental illness in patients to accelerating learning and improving concentration in healthy people.
To date, more than 15,000 scientific experiments on humans have been conducted on the effects of tDCS on literally everything from schizophrenia to tinnitus treatment. However, the trouble of research is their strong heterogeneity: different exposure parameters (stimulation time, current strength, etc.) and different research quality - from good double-blind, placebo-controlled - to works in which there is not even a placebo group. Attempts to synthesize current knowledge of tDCS have already been made , but they have sinned by taking the analysis with different designs and sample sizes.
A large-scale study of a large team of neuroscientists from France, Germany, Switzerland, New Zealand, Italy and Belgium is perhaps the first example of a qualitative understanding of the influence of tDCS on various diseases. How tDCS can improve the cognitive functions of healthy people is the subject of a separate discussion previously covered .
Electrical stimulation helps with depression, chronic pain and addictions
Scientists analyzed a huge array of tDCS studies: no more, no less than 1,412 articles, in which more than 8,000 people participated, and selected works with only high-quality design among them.
The experiments were supposed to be with a control group of people (whose stimulation was imitated to exclude the placebo effect), as well as randomized ones (that is, subjects were randomly divided into groups). In all studies, people had to undergo not one tDCS session (which may not be enough for the effect), but several. In addition, higher priority was given to studies in which more than 25 people took part, and studies in which there were less than 10 participants were not taken into account at all.
Analysis of these studies has shown that tDCS is effective for treating several common diseases: depression, chronic pain, and addictions (for example, for alcohol, nicotine, and even soft drugs), but it does not help with chronic tinnitus. Based on these studies, scientists concluded that electrostimulation is effective in the case of those diseases where restructuring of the brain is not required.
Mechanism of action
The principle of operation of tDCS is not too complicated. Electrodes applied to the scalp affect the brain with a weak direct current (1-2 milliamperes). A positively charged electrode (“anode”) reduces the potential difference across the neuron membrane, which facilitates their excitation in the event of signals from neighboring neurons. A negatively charged electrode (“cathode”), on the contrary, increases the potential difference, reducing the excitability of neurons.
The result of a few minutes of electrical stimulation is an increase in the activity of the cerebral cortex under the anode, which lasts an hour or more after the procedure is completed. In the case of conducting tDCS for several days in a row, changes in interneuronal contacts , synapses, occur in the cortex neurons. For example, they may increase in size, which facilitates the transmission of a signal from one neuron to another. This process is called synaptic plasticity, and it is he who is responsible for preserving the effects of tDCS after completion of the course of effects.
Principle of treatment of depression
The principle on which treatment of depression with tDCS is based is also quite simple. Studies show that depressed patients differ in the activity of certain areas of the frontal lobes of the cortex of the left and right hemispheres. Electrical stimulation is designed to compensate for this imbalance. To do this, over the less active brain area have a positively charged electrode ("anode"), which slightly increases its activity.
The analysis showed that electrostimulation of 20-30 minutes a day for at least several days in a row leads to a steady improvement in the condition of patients with severe, clinical form of depression. For this, correct positioning of the electrodes is crucial. The anode should be located above the left prefrontal cortex (DLPFC) - F3, and the cathode - on the right supraorbital region - FP2. Interestingly, if you move the cathode a few inches higher - the effect disappears.
Scientists assigned this conclusion “Class B”, that is, “technology is likely to be effective” and believe that in order to recognize electrostimulation as uniquely effective, research should be conducted with a large number of participants. However, transcranial electrostimulation has already been approved for the treatment of depression in Europe .
Electrostimulation vs antidepressants
Interestingly, a direct comparison of tDCS and some antidepressants shows that electrical stimulation is not inferior to them in terms of effectiveness. For example, a double-blind, randomized study by scientists from Harvard demonstrated that after tDCS, patients with depression recovered faster than after taking fluoxitin, a selective serotonin reuptake inhibitor.
Another study showed that tDCS is not inferior to sertraline, another popular anti-depressant. It is important to note that in the case of a combination of both effects (electrical stimulation with an antidepressant) - the effect was superior to each of the therapies separately.
However, if the efficacy of tDCS and antidepressants (at least some) is similar, in terms of safety, electrical stimulation significantly outpaces them. Indeed, the side effects of antidepressants can be quite serious (up to obesity, sexual problems and even hallucinations).
Side effects at tDCS are much less significant. Although they were closely monitored in each of the studies, among the undesirable consequences for patients, periodically, there was only a slight tingling and burning sensation, as well as skin irritation in the areas of electrode attachment.
Cure depression at home?
However, today the tDCS technology has one major drawback. For treatment, patients are forced to go to the clinic for procedures (unlike antidepressants, which can be taken at home on their own).
That is why several companies set about developing portable medical devices for home use. These are, for example, the New York company Soterix Medical and the Korean startup Ybrain . In addition, several non-medical tDCS devices are already being produced, offering the same arrangement of electrodes for depression under the sign of "improving mood".
Andre Bruoni, a neuroscientist and psychiatrist at the University of SĂŁo Paulo, believes that such devices have 3 potential advantages:
- Price: Since tDCS devices are relatively cheap, people will prefer technology over transcranial magnetic stimulation (TMS) over them.
- Ease of use: Brouoni says that startups like Soterix "are developing very safe and reliable devices for home use with almost zero risk."
- Short treatment: tDCS therapy for depression will begin with an intensive course - for example, 2 weeks of daily electrostimulation sessions - after which much rarer sessions will be held to maintain the effect. This is a great advantage over antidepressants, which often require courses from 9 months (during which they can cause negative side effects).
TDCS to improve mood?
Interestingly, electrical stimulation from depression (“anode” - on the left dorsolateral prefrontal cortex) can be useful for healthy people. For example, in 2016, a double-blind, placebo-controlled study on 66 healthy volunteers showed that electrical stimulation significantly improved the general mood of the subjects, including reduced anxiety, depression, hostility to others, reduced fatigue and a sense of confusion.
Another study of the same year, conducted by Oxford scientists on 60 healthy people, showed that tDCS increases a person’s resistance to stress.
Against the background of the constant increase in the number of such studies, a rather large community of people who use tDCS in their daily lives has been formed. On the Reddit site alone, more than 8,000 people are constantly sharing their experiences using tDCS devices, while about 30% tried using technology to treat depression (other users use tDCS to improve memory, concentration and concentration).
For procedures, people use special non-medical devices - designed for everyday use, which are already being released in the USA - Thebrainstimulator , Hong Kong - Priormind and since last year - in Russia - Brainstorm neurostimulator . All of them allow the electrodes to be placed on several (up to 10) different zones of the head, for different cognitive effects, among which there is an improvement in mood.
It is a curious fact that in the first non-medical tDCS device, manufactured by the American company foc.us and intended to improve the reaction and concentration of attention of gamers, the electrodes were located precisely to improve mood (from depression):
It is possible that this is why such a device was popular: although it did not directly affect the reaction and memory, it improved the mood and due to this the users liked it. However, foc.us subsequently corrected its mistake and the similar device is no longer produced.
Many scientists, however, are wary of the independent use of tDCS, which is fraught with many inadvertent errors (for example, improper placement of electrodes on the head or too long an exposure time - instead of 20-30 minutes), which can lead to undesirable results. But on the other hand, scientists themselves are now proposing that people use tDCS at home as part of scientific experiments, when they are convinced that people fully comply with safety precautions.
Source: https://habr.com/ru/post/373157/
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