Neurostimulation: New Frontiers in Mental Health Treatment

In this episode of the Neurostimulation Podcast, host Dr. Michael Passmore, Clinical Associate Professor at the University of British Columbia, delves into a groundbreaking meta-analysis on the efficacy of neurostimulation techniques like TMS and tDCS across various mental disorders. Covering 208 randomized controlled trials, the discussion highlights the potential of these techniques in treating conditions such as generalized anxiety disorder, substance use disorders, obsessive-compulsive disorder, depression, schizophrenia, and PTSD. Passmore breaks down the results, emphasizing the importance of protocol standardization, discusses the implications for clinical practice, and explores future research directions and innovations in neurostimulation. Listeners are encouraged to consider the challenges and opportunities within this evolving field and to stay engaged for upcoming episodes focusing on personalized mental health care.

00:00 Welcome to the Neurostimulation Podcast

02:52 Introduction to Neurostimulation Techniques

07:12 Key Findings from the Meta-Analysis

11:06 Clinical Implications and Future Directions

17:29 Advanced Evidence-Based Critical Analysis

24:18 Summary and Final Thoughts

Study:

https://pubmed.ncbi.nlm.nih.gov/35365806/

Resources:

Transcranial Direct Current Stimulation (tDCS):

Centre for Addiction and Mental Health (CAMH): Provides an overview of tDCS, its applications, and ongoing research into its efficacy for major depressive disorder. 

https://www.camh.ca/en/your-care/programs-and-services/therapeutic-brain-intervention-service

Wikipedia - Transcranial Direct-Current Stimulation: Offers detailed information on the technique, its mechanisms, clinical applications, and current research findings. 

https://en.wikipedia.org/wiki/Transcranial_direct-current_stimulation

The Times - Discusses recent research on the efficacy and safety of home-based tDCS devices for treating depression.

https://www.thetimes.co.uk/article/electrifying-your-brain-at-home-can-treat-depression-study-finds-btdbjz2gh

Repetitive Transcranial Magnetic Stimulation (rTMS):

Centre for Addiction and Mental Health (CAMH): Provides an overview of rTMS, its applications, and current research studies focusing on psychiatric conditions such as major depression, obsessive-compulsive disorder, and schizophrenia. 

https://www.camh.ca/en/health-info/mental-illness-and-addiction-index/repetitive-transcranial-magnetic-stimulation

Nova Scotia Health: Offers a detailed pamphlet explaining how rTMS works, potential side effects, and what patients can expect during treatment sessions. 

https://www.nshealth.ca/patient-education-resources/1975

Sunnybrook Health Sciences Centre: Discusses the use of rTMS as a treatment for depression, including patient experiences and insights from medical professionals. 

https://health.sunnybrook.ca/mental-health/rtms-depression-treatment/

Mental Health General: Provides an in-depth article on rTMS, covering its mechanisms, effectiveness, and the mental health conditions it may help treat. 

https://www.mentalhealthgeneral.com/repetitive-transcranial-magnetic-stimulation-everything-you-need-to-know/

The Royal’s Institute of Mental Health Research: Features information on their Neuromodulation Research Clinic, which offers personalized rTMS treatments for depression and ongoing research initiatives. 

https://www.rtmsresearch-ottawa.ca/

Welcome to the Neurostimulation Podcast.

2

I'm Michael Passmore, Clinical

Associate Professor in the Department

3

of Psychiatry at the University of

British Columbia in Vancouver, Canada.

4

The Neurostimulation Podcast is all

about bringing cutting edge neuroscience

5

and neurostimulation education to

you every week, free of charge.

6

We're going to look at the latest

research breakthroughs, how the

7

technology works and most importantly,

how all of this is being translated

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into real world treatments that

can improve health and wellbeing.

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So whether you are a researcher, a

clinician, a student, or just somebody

10

who's curious about how our brains

work and what we can do to help them to

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work better, this podcast is for you.

12

My mission is to make the

science accessible, inspiring,

13

and relevant to your daily life.

14

As part of my commitment to evidence based

analysis, in every episode that we discuss

15

a specific study, I'm going to include an

advanced critical appraisal of that study.

16

If you're not interested in this

deeper dive into the methodology

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and analysis, feel free to skip

ahead on the timeline to focus in

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on other aspects of the discussion.

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This podcast is separate from my clinical

and academic roles and is part of my

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personal effort to bring neuroscience

education to the general public.

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Accordingly, I would like to emphasize

that the information shared in

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this podcast is for educational

purposes only, and is not intended

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as medical advice or a substitute

for professional medical guidance.

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Always consult with your health care

provider to discuss your own specific

25

health needs and treatment options.

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By listening to or watching this

podcast, you acknowledge and agree that

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any decisions related to your health

care are your own responsibility and

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should be made in consultation with

a qualified medical professional.

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This episode is presented

by ZipStim Neurostimulation.

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Full disclosure, ZipStim is

the neurostimulation clinic

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that I own and operate.

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You can find out more about our clinical

neurostimulation programs at zipstim.com.

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That's Z I P S T I M dot com.

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Now let's get started.

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Mike: Today we're going to explore

a groundbreaking study that could

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change how we view non invasive

brain stimulation for mental health.

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This episode focuses on a comprehensive

review and meta analysis titled,

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Efficacy of Neurostimulation Across

Mental Disorders, Systematic Review

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and Meta Analysis of 208 Randomized

Controlled Trials, published in

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the journal Molecular Psychiatry.

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We're spotlighting the largest meta

analysis to date on neurostimulation,

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covering an incredible 208

randomized controlled trials.

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This study provides a comprehensive

look at two key techniques,

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transcranial magnetic stimulation,

or TMS, and transcranial direct

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current stimulation, or tDCS.

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It evaluates their effectiveness across

a range of mental health conditions.

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from depression and anxiety

to schizophrenia and PTSD.

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So why does this matter?

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As mental health challenges continue

to rise globally, especially in

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the wake of the COVID 19 pandemic,

there is an urgent need for safe,

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effective, and accessible treatments.

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Neurostimulation is emerging as a

powerful tool, offering hope where

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traditional therapies might fall

short or are poorly tolerated.

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But what do the numbers say?

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Which conditions show the most promise?

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And how do we navigate the

challenges of translating this

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research into real world practice?

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In this episode, we'll break down the

findings of this monumental study and

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we're going to explore the mental health

conditions, where neurostimulation

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has shown the greatest potential.

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So grab a cup of coffee or your

favourite beverage and let's get started.

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By the end of the episode you'll

have a clearer understanding of

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how neurostimulation fits into the

broader landscape of mental health

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care and where it's headed next.

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Let's start by setting the stage.

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The study that we're discussing

today is a meta analysis, which is

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essentially a way to synthesize data

from multiple high quality studies.

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It provides a bird's eye view of how

effective neurostimulation really is

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for various mental health conditions.

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Now what makes this particular meta

analysis stand out is its scope.

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It includes 208 randomized controlled

trials, making it the largest synthesis

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of its kind for transcranial magnetic

stimulation, or TMS, and transcranial

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direct current stimulation, or tDCS.

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So what exactly are TMS and tDCS?

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If you're new to the podcast,

here's a quick refresher.

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TMS uses magnetic fields to induce

electrical currents in targeted brain

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regions, altering neural activity.

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It's most commonly delivered as repetitive

TMS or rTMS and can be either high

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frequency or low frequency stimulation.

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tDCS, on the other hand, uses

low electrical currents delivered

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through electrodes on the scalp.

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It doesn't induce neuronal firing

directly, but modulates brain

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activity, making the neurons more

or less likely to fire, depending

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on the polarity of the current.

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This meta analysis doesn't

just look at one condition.

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It spans multiple disorders, including

depression, which is by far the most

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studied, generalized anxiety disorder,

or GAD, Obsessive Compulsive Disorder,

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or OCD, Post Traumatic Stress Disorder,

or PTSD, Schizophrenia, focusing on both

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positive and negative symptoms, Substance

Use Disorders, and even cognitive

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deficits like attention and working memory

issues in disorders like Schizophrenia.

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So what did they measure?

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Outcomes included reductions in core

symptoms like depression or anxiety

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severity and improvements in cognitive

functions such as attention, working

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memory, and executive functioning.

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This broad approach provides

us with valuable insights into

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where neurostimulation excels and

where it might need refinement.

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/ . Let's break down the

findings of this study.

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The results of this meta analysis

are both exciting and nuanced.

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Let's go through them condition

by condition, highlighting where

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neurostimulation shows the most promise.

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First, let's look at generalized

anxiety disorder, or GAD.

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TMS was a clear standout

here, with a large effect

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size, or SMD of negative 1.8.

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Only three RCTs were included, but all

use different stimulation protocols,

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including both high frequency and

low frequency stimulation of the

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right dorsolateral prefrontal cortex,

or DLPFC, and parietal cortex.

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This consistency across protocols

suggests a strong potential for TMS in

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treating GAD, although more research is

needed to refine the best parameters.

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Second is Substance Use Disorder, or SUD.

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tDCS showed a medium to large

effect size, an SMD of negative

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0.73 , for reducing cravings and

symptoms related to substance use.

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No significant heterogeneity was

found, which means that these

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results were fairly consistent.

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This is exciting because SUD, Substance

Use Disorder, is notoriously difficult

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to treat and tDCS could provide a new

non invasive option for helping patients.

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Third is Obsessive

Compulsive Disorder, or OCD.

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TMS demonstrated a medium effect size, or

SMD, around negative 0.66, with specific

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protocols showing even stronger results.

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The bilateral DLPFC stimulation

stood out as particularly

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effective, with low heterogeneity.

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Low frequency stimulation of the

supplementary motor area, or SMA, and

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also right DLPFC also showed promise.

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These findings highlight the importance

of tailoring TMS protocols to specific

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brain regions and symptom profiles.

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What about unipolar depression

or major depressive disorder?

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TMS and tDCS were both effective.

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High frequency stimulation of

the left DLPFC, a commonly used

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protocol, had a medium effect size.

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Bilateral stimulation showed

a smaller but more consistent

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effect with less heterogeneity.

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This reinforces the idea that TMS

can be a game changer for patients

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with treatment resistant depression,

but protocol optimization is key.

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Fifth is schizophrenia.

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TMS and tDCS were effective for

negative symptoms with medium

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effect sizes, but results for

positive symptoms were less clear.

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tDCS was particularly promising

for improving attention and working

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memory, addressing cognitive deficits

that medications often fail to treat.

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This is a significant step forward, as

cognitive symptoms are a major barrier

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to functional recovery in schizophrenia.

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Sixth is post traumatic

stress disorder, or PTSD.

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TMS demonstrated a large effect

size with an SMD of negative 1.09,

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especially with low frequency

stimulation of the right DLPFC.

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This aligns with growing evidence

that targeting specific brain

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regions can effectively alleviate

PTSD symptoms, including hyper

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arousal and intrusive thoughts.

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Across these findings, what's clear

is that both TMS and tDCS hold

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incredible potential for treating

mental health conditions that are often

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resistant to traditional therapies.

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But it's not just about

whether these techniques work.

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It's also about fine tuning the

protocols to maximize their effectiveness

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and ensure consistent results.

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Now that we've unpacked the findings of

this study, let's explore what they mean

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for clinical practice and patient care.

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Neurostimulation techniques like TMS

and tDCS are not just promising, they're

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already reshaping how we approach

some of the most challenging mental

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health conditions First, let's look at

standardizing protocols for effectiveness.

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One of the most striking takeaways

from this meta analysis is the

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importance of session frequency

and protocol standardization.

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For example, the analysis suggests that 10

to 20 sessions of TMS are optimal across

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conditions like depression, PTSD, and OCD.

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Interestingly, extending beyond

20 sessions doesn't appear to

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necessarily lead to greater benefits.

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What about treatment resistant cases?

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Conditions like unipolar depression

or major depressive disorder,

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PTSD and negative symptoms in

schizophrenia are notoriously

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difficult to treat with traditional

pharmacotherapy and/or psychotherapy.

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Neurostimulation offers a viable

alternative or complement to these

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other therapies, giving clinicians

more tools to help their patients.

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For example, transcranial magnetic

stimulation can help patients

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who haven't responded to multiple

antidepressant trials, reinforcing

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its role as a frontline treatment

for treatment resistant depression.

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What about cognitive deficits?

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Cognitive symptoms, especially

in conditions like schizophrenia,

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are often under-addressed

by conventional treatments.

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These findings suggest that tDCS can

improve attention and working memory.

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which could significantly enhance

functional outcomes for patients.

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These kinds of improvements can translate

into better everyday functioning,

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such as improved job performance or

general ability to manage daily tasks.

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What about combining treatments

for a synergistic effect?

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The study focused on neurostimulation

as a standalone therapy.

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But previous research indicates

that combining it with other

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interventions can amplify its effects.

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For instance, TMS plus cognitive

behavioral therapy, or CBT, particularly

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promising for anxiety and PTSD.

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tDCS plus cognitive training, a

potential game changer for ADHD and

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cognitive deficits in other disorders.

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These approaches suggest that

future protocols might pair

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neurostimulation with existing

therapies for a more holistic approach.

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How about expanding accessibility?

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One exciting aspect of tDCS is its

potential for home-based treatment,

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particularly for conditions like

substance use disorders and depression.

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This could make neurostimulation more

accessible, especially for individuals

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who face barriers to in-clinic treatment.

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There's also the potential for app-based

monitoring or remote supervision to

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help ensure safety and improve efficacy.

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Ultimately, the findings of this

study remind us that neurostimulation

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isn't just about treating symptoms.

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It's about restoring function, hope,

and agency to patients who may have felt

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left behind by other treatment options.

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While the results of this meta

analysis are promising, They're also a

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reminder that the journey of advancing

neurostimulation is far from over.

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Let's discuss the key challenges

and where we go from here.

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First, there are still

significant research gaps.

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For example, conditions like ADHD and

tic disorders remain underexplored with

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too few studies to draw firm conclusions.

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We also need more RCTs exploring

long-term effects and how well

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benefits are sustained over time.

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Ongoing research is going to

be very important to address

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these gaps in our knowledge.

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What about managing heterogeneity?

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One of this study's major

limitations was heterogeneity or

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variability in results across trials.

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Factors like stimulation site,

frequency intensity, and patient

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demographics all influence outcomes.

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For instance, high frequency TMS

on the left DLPFC shows promise for

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treating depression, but results vary

widely depending on the number of

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sessions and patient characteristics.

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Future research must identify the best

parameters for each condition, tailoring

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treatments to maximize efficacy.

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How about ethical and

practical considerations?

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Accessibility and

affordability are crucial.

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While tDCS offers potential for home-based

treatment, ensuring proper supervision and

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preventing misuse is going to be critical.

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Similarly, TMS's cost and reliance on

specialized equipment can limit its reach.

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There is a need for policies and

programs to help make neurostimulation

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more affordable and available

to underserved populations.

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What are some innovations on the horizon?

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Emerging technologies like closed

loop neurostimulation, which adapts

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stimulation in real time based on

brain activity, could dramatically

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improve precision and outcomes.

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We need to explore the potential for AI

driven personalization, where machine

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learning algorithms help to identify the

best protocols for individual patients.

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What about combining

modalities for greater impact?

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We've discussed combining neurostimulation

with CBT or cognitive training approaches,

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but what about pairing TMS with tDCS?

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Could these two techniques work

synergistically to address both symptoms

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and underlying brain dysfunction?

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This might be an exciting

area for future exploration.

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The future of neurostimulation is bright.

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But it requires collaboration across

research clinical practice and policy

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in order to fully unlock its potential

Now i'd love to hear from you.

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What are your thoughts on these

challenges and opportunities?

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Reach out to share your

perspective or suggest topics

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for future podcast episodes.

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Now I'm going to offer an advanced

evidence-based critical analysis of this

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study using the PRISMA analysis, PRISMA

stands for the Preferred Reporting Items

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for Systematic Reviews and Meta Analyses,

is a checklist and a framework that allows

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us to highlight both the study's strengths

and potential areas for improvement.

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First, let's look at the

title and the abstract.

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What about the strengths?

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The study's title clearly

conveys its purpose.

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A systematic review and meta analysis

of neurostimulation techniques, TMS and

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tDCS, across mental health disorders.

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The abstract effectively summarizes

the key findings, objectives,

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and methods, providing a

comprehensive snapshot for readers.

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What are some areas for improvement?

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Well, the abstract could provide more

detailed information on limitations,

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such as heterogeneity or publication

bias to give a balanced view up front.

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Second, let's look at the introduction.

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What were the strengths?

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The introduction establishes a strong

rationale for the study by highlighting

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gaps in neurostimulation research and

the need for comprehensive synthesis.

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The objectives are clearly

stated, aligning with PRISMA

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guidelines to ensure transparency.

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What are some areas for improvement?

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It could elaborate on how this study

builds on previous meta analyses or

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systematic reviews, differentiating its

contribution to the field in general.

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Third, let's look at the methods.

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What were the strengths?

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The study adheres to PRISMA's

emphasis on a detailed methodology.

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It specifies inclusion

and exclusion criteria.

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search strategies across

databases, and the statistical

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methods used for meta analysis.

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The use of randomized controlled trials,

or RCTs, ensures high quality data,

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minimizing the potential for bias.

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While the study includes 208 RCTs, it

doesn't clarify how grey literature,

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such as unpublished studies or non

English studies, were handled, which

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may introduce some publication bias.

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The heterogeneity of the protocols,

for example, variation in stimulation

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sites, frequencies, and session

counts, is acknowledged, but not fully

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addressed in terms of its potential

impact on pooled effect sizes.

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Fourth are results.

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What were the strengths?

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Well, the results were well organized

with clear subgroup analyses for specific

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disorders, like GAD, OCD, and depression.

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The effect sizes, or SMDs, are

reported with confidence intervals.

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which helps in assessing the

precision and reliability of findings.

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What about the limitations in reporting?

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High heterogeneity, or I squared

values, is reported for some outcomes,

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but not consistently explained.

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The PRISMA guidelines recommend

sensitivity analyses, or meta regression,

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in order to address heterogeneity,

which could strengthen the findings.

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There's no discussion of small

study effects or potential biases in

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specific subgroups, such as studies

with high versus low risk of bias.

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Fifth is the discussion.

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What were the strengths?

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Well, the discussion contextualized the

findings within existing literature,

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highlighting where neurostimulation has

strong evidence and where gaps remain.

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The clinical implications are

thoughtfully explored, including the

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importance of protocol standardization

and the potential for home-based tDCS.

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What would be some areas for improvement?

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Well, the study does not sufficiently

address limitations such as the

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reliance on studies with small sample

sizes, short follow-up durations,

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or lack of blinding in some trials.

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The discussion could also include a

more robust critique of the variability

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in effect sizes, particularly for

conditions like depression, where

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multiple protocols are in use.

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Then there's the risk of bias assessment.

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What were the strengths?

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Well, the study included a risk of

bias assessment for included RCTs,

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which is a key PRISMA requirement.

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Use of standardization tools,

for example, the Cochrane risk of

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bias tool, ensures credibility.

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But what about the limitations?

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While the assessment identifies high

risk studies, it doesn't adequately

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explore how these studies may have

influenced the meta analysis results.

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Exclusion or subgroup analyses for high

risk studies could have added clarity.

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Limitations and future directions.

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What were the strengths?

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The authors acknowledge heterogeneity

and the need for more targeted

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studies in underrepresented conditions

like ADHD and tic disorders.

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Calls for standardizing protocols,

for example, session count,

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stimulation parameters, are

valuable for advancing the field.

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What could be some areas for improvement?

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Well, the study could expand on

the ethical and practical barriers

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to implementing neurostimulation

more widely, such as cost,

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accessibility, and patient adherence.

328

There could have been a greater emphasis

on the need for large scale, multi center

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trials with longer term follow up, which

could help to guide future research.

330

Let's look at the overall

quality and contribution.

331

What were the strengths?

332

This study is a landmark synthesis

offering the most comprehensive

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evidence to date on TMS and tDCS

across mental health conditions.

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Its findings provide actionable insights

for clinicians and researchers reinforcing

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neurostimulation's role in treating

treatment-resistant conditions, and

336

in offering patients an alternative

to traditional treatment options.

337

As a final critique, this study excels

in scope and rigor, but it could benefit

338

from a deeper analysis of variability

and publication bias, as well as more

339

practical recommendations for integrating

the findings into clinical practice.

340

Using the PRISMA framework to critique

this study highlights its strength

341

as a comprehensive meta analysis

while pointing out areas where future

342

reviews and research could improve.

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By addressing these limitations, the

field of clinical neurostimulation can

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advance even further, offering more

precise, effective, and accessible

345

care options for mental health.

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Okay, let's quickly recap the

highlights of what we've covered.

347

Let's summarize the key takeaways

from today's discussion.

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We started by exploring the largest

meta analysis to date, which evaluated

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208 randomized controlled trials on

TMS and tDCS across various conditions.

350

We learned that TMS shows strong

potential for treating conditions like

351

GAD, OCD, PTSD, and major depressive

disorder, while tDCS excels in addressing

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cognitive deficits in schizophrenia

and symptoms of substance use disorder.

353

We discussed how tailoring protocols

like focusing on specific stimulation

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sites, or standardizing session counts

can optimize outcomes for patients.

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And finally, we tackle the challenges,

including research gaps, heterogeneity

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in results, and the need for greater

accessibility and affordability in

357

neurostimulation treatment options.

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These findings aren't just numbers.

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They're a testament to how far we've

come in understanding and harnessing

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the power of neurostimulation

in helping the brain to heal.

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Neurostimulation represents a frontier in

mental health care, but it's also a field

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where there's so much more to discover.

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Every study, every clinical trial,

and every patient experience

364

adds another piece to the puzzle.

365

Did today's discussion

spark your curiosity?

366

Maybe you're a clinician thinking about

incorporating neurostimulation into your

367

own practice, or maybe you're a researcher

interested in the next big questions.

368

I would love to hear your thoughts.

369

Share them with me on our social

media outlets or through the podcast

370

website on the comment section below

any way that works best for you.

371

If you're a researcher or a clinician,

consider joining the movement to

372

push neurostimulation forward.

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Collaborate on studies, refine protocols,

or explore how these techniques can

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complement traditional therapy options.

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And don't forget to tune in next

time, where we're going to be

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looking in a fascinating direction

that could redefine how we approach

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personalized mental health care.

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For more resources, insights, or to catch

up on previous episodes, please visit

379

our website or follow us on social media.

380

If you've enjoyed today's episode,

don't forget to like and subscribe,

381

and also feel free to leave a review.

382

It really helps us to reach

more people who are passionate

383

about mental health innovation,

neuroscience, and neurostimulation.

384

Thank you so much for joining me

today on the Neurostimulation Podcast.

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I sincerely appreciate your time,

your interest, and your attention.

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Until next time, stay curious, stay

compassionate, and let's keep exploring

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the future of mental health care together.