Deep Brain Stimulation for Schizophrenia

Expanding the horizons of a technique that’s been around for decades to treat Schizophrenia based on modern advances in science and technology.

Table Of Contents

1. Introduction
2. How does DBS work?
3. What is Schizophrenia?
4. What makes DBS for Schizophrenia harder to achieve than for other Psychiatric conditions?
5. How would DBS for Schizophrenia work?
6. The Road to Success
7. Key Takeaways

Introduction

In 1987, an invasive neurotechnology called Deep Brain Stimulation (DBS) was first developed by a group of French scientists working on a treatment for essential tremor. Since then, it’s become widespread as a treatment for essential tremor as well as other movement based disorders such as Parkinson’s and dystonia. However, over the past two decades the horizons of this technology have been expanded to certain types of psychiatric disorders such as Major Depressive Disorder and OCD.

Deep Brain Stimulation has been being used for Parkinson’s and essential tremor for decades.

As soon as this shift begun, people began to experiment with utilizing Deep Brain Stimulation for a variety of brain based conditions such as Alzheimer’s, Epilepsy, Anorexia nervosa, and even addiction. They were able to progress DBS treatments for each of these conditions into advanced phases of trials, and the results looked very promising. However, at the time, there was one specific condition where the testing couldn’t even make it to the clinical stages: Schizophrenia. DBS for this condition presented barriers which at the time, scientists weren’t equipped with the technology to address. So this condition was left behind while other DBS treatments helped patients in new influential ways.

That said, it’s now 2021. The past decade and a half have yielded exponential advances across the board in the world of science and technology. Ambitious scientists have brought all sorts of new technologies to life, incorporating entities such as video games and virtual reality into modern treatments of neurological conditions. Although DBS has seemingly been around for decades, its continuous widespread efficacy make it worthy of revisiting for the Schizophrenic patients in need whom it never reached. With the modern advances in science and technology, using Deep Brain Stimulation for patients with Schizophrenia is a possibility we can bring to life, and one surely worth the work it will require.

How does DBS work?

Deep Brain Stimulation is initiated through a type of invasive Brain Computer Interface (meaning it’s located inside the skull directly in or on the brain) called a deep Brain Computer Interface (dBCI). The dBCI sends trains of consistent electrical pulses to the areas it is targeting, which vary based on the condition they’re being used to treat. The pulses then reach neurons from the target area, and the treatment is able to spread throughout that region based on a natural technique called neuromodulation where a neuron uses chemicals to control other nearby populations of neurons.

The parts of a DBS device

Current DBS systems operate in an open loop manner, where the brain can receive the pulses from the dBCI, but the device can’t read any brain signals. A current project being worked towards in this field is creating a bidirectional DBS device that can send and receive signals.

What is Schizophrenia?

Schizophrenia is a chronic psychotic disorder experienced by over 20 million people worldwide that impacts one’s ability to think, feel, and behave clearly. Schizophrenics often experience thoughts or experiences that seem out of touch with reality (delusions or hallucinations), disorganized speech or behavior, decreased participation in daily activities, and highly disorganized or abnormal motor behavior among other symptoms.

Symptoms of schizophrenia are sorted into two categories: positive and negative. Positive symptoms (which include hallucinations, delusions, disorganized thoughts or speech, etc.) are symptoms a person experiences in addition to common experiences, which a person without the condition or a similar one would not experience at all.

Patients with Schizophrenia can experience both positive and negative symptoms.

Negative symptoms, also known as deficit symptoms (such as lack of emotion, lessened joy or motivation, delayed speech, difficulty beginning and continuing activities, etc.) are symptoms which exist as deficits of qualities that an average individual experiences in greater quantities or frequencies. These deficits can be sorted into four main categories: relational, communicative, affective, and avolition/conational (motivation based).

While research has been unsuccessful in identifying a single root cause of Schizophrenia, it is thought to be a combination of genes, environment, and psychosocial factors. Schizophrenia has no known cure, but it can be treated, typically through a combination of antipsychotic medication, psychotherapy, and coordinated specialty care services (recovery oriented treatment programs). However, up to 30% of patients on antipsychotics are resistant to the medication, so it’s evident a new alternative is needed.

What makes DBS for Schizophrenia Harder to Achieve than for Other Psychiatric Conditions?

There are many factors that separate Schizophrenia from other psychiatric disorders with regards to making it a use case of Deep Brain Stimulation. One of the most obvious is that the dBCI would need to target certain brain regions that none of the other conditions required for treatment. For positive symptoms of Schizophrenia, an example of this is the need to target the temporal cortex (responsible for functions such as creating conscious memory, language comprehension, and behavior). For negative symptoms, a unique target area is the ventral tegmental area (VTA) which is responsible for reward, motivation, cognition, and aversion.

Another setback lies in the protocol executed during trials to achieve an accurate model. There is an abundance of observation and testing required during trials and in order to design a good prototype, which is always executed using an animal model. This animal is typically some form or rat or mouse. Not only is Schizophrenia not found in these rodents, no other species on Earth can get Schizophrenia. Scientists presume this is based on the significant complexity of the human brain and its parts versus that of other animals. Regardless, this makes it more challenging to gain a good understanding of the condition as it cannot be experienced by other animals and humans cannot be as observed as easily in this capacity.

Typically, DBS treatments are tested on mice.

In addition, a more simple barrier which has prevented Schizophrenics from having access to this treatment is the lack of trials based on these other barriers. Although technology has been advancing and making it easier for this to be achieved, a technique cannot and will not be approved to become a widespread treatment without many trials and evidence to support the fact that it’s safe, effective, and consistent.

How would DBS for Schizophrenia Work?

There are several different mechanisms that can be executed by Deep Brain Stimulators depending on the goal of the treatment. Given the fact that positive and negative symptoms of Schizophrenia are essentially opposites while still being parts of one same condition, they would each need to be targeted with opposite mechanisms. While positive symptoms need Direct inhibition (suppression or blocking) of neural activity, negative symptoms need Direct excitation of neural activity.

A DBS device can perform a variety of different functions depending on what it’s being used to treat.

There would also be a slight variance in the brain regions targeted for each type of symptom. Both types of symptoms require targeting the nucleus accumbens (naCC), but as stated already positive symptoms also require targeting of the temporal cortex while negative symptoms should be treated in the VTA.

Since patients with Schizophrenia can experience both positive and negative symptoms, one patient would need their dBCI to extend to many different regions, making it slightly larger and more complex. However, conditions which have recently been approved for DBS treatments such as OCD need to target up to 5 different areas, so this should be achievable.

Although they may be substantially different conditions than Schizophrenia, the recent approval of Deep Brain Stimulation for other psychiatric conditions such as OCD and Major Depressive Disorder act as a case study for how modern innovation and technology enable DBS to become a treatment option for many conditions that it was previously not doable for. They help ground the idea that this technology could be successfully adapted to treat Schizophrenia, and plausible to begin executing immediately without waiting to wait any longer for upcoming technology.

The Road to Success

I’ve already provided many specific details on what would be required of the technology, where it should target, and what features it should have. Given the fact that this technology already exists for other conditions, there’s a preexisting protocol on how to design and implant dBCI devices once they’re approved. The main difference in execution will be in the trials.

Since there are no animals who experience Schizophrenia, observation will either have to be gained from human observations (which will likely require different tactics than mice) or from preexisting data and experiments.

The majority of the time it takes to create a DBS Schizophrenia treatment will likely spent on trials. Before this treatment can get approved by the FDA as its DBS predecessors were, there will need to be many trials. Although this treatment is clearly feasible and evidence suggests it can make it through all phases of trial to become mainstream at least for drug resistant patients, there will still be many issues that arise and tests which will need to be done in order to release the best version of the product. This will take time as it always does, but that says nothing about the practicality or efficacy of the product itself.

Finally, the DBS will make it through each phase of trials and should gain approval from the FDA. Over time it will become more widely accepted, accessible and affordable. When invasive BCI products such as this one first release, there’s typically resistance especially from older members of society. However, as they become more common, the initial resistance typically wears off which will enable the product to be successful financially.

Ultimately, once DBS can be used to treat Schizophrenia, it will have very good scalability and can also become an option for patients with a variety of Psychotic disorders and conditions. Just as it has for patients with other conditions, DBS for Schizophrenia will impact millions of lives and help people with Schizophrenia live with less impairment from their condition.

Key Takeaways

1. Deep Brain Stimulation (DBS) has been around to treat essential tremor and Parkinson’s for decades. Recently, it’s been expanded to also help treat psychiatric disorders such as MDD and OCD.
2. It previously could not be executed as a treatment for Schizophrenia for a variety of reasons, but with these new expansions as well as advances in science and technology, it’s now possible.
3. DBS is performed by a deep Brain Computer Interface which sends trains of electrical pulses to target brain regions, and the treatment spreads with the use of a naturally occuring technique called neuromodulation.
4. Schizophrenia is a psychotic disorder that impacts one’s ability to think, feel, and behave clearly. Schizophrenics can experience positive symptoms such as delusions and hallucinations which are additional experiences the average person doesn’t have, and negative symptoms such as lack of motivation and reduced speech which manifest themselves as deficits in qualities the average person demonstrates.
5. Using DBS for Schizophrenia is different than other conditions for many reasons such as the different brain regions being targeted, the lack of animal subjects since no animals have Schizophrenia, and the lack of preexisting trials for it
6. While some substantial adjustments would need to be made in order to achieve a DBS device that could treat Schizophrenia, based on the preexisting devices now used to treat other psychiatric conditions and the advances in modern innovation and technology, it is certainly feasible with some substantial adjustments.

Thanks for reading my article, I hope you enjoyed! My name is Raina Bornstein, I’m 15 years old and I’m passionate about neuroscience and brain based disorders. I’d love to connect on LinkedIn, or you can reach out to me at rainabornstein@gmail.com to talk or collaborate. I can’t wait to hear from you!