Have you ever been prescribed antidepressant medication? If so, you were probably recommended to stay on them for at least a year, even if the medication started working within two months. Why?

Because depression has a habit of coming back.

The first 6-12 months following treatment is a sensitive period where you are at higher risk of relapse. During that period, the brain is more prone to falling back into depressive thinking and functioning.

You can imagine the process of recovering from depression as moving into a new home. As you recover, you put a lot of effort into sorting out the old patterns and obstacles that you want to leave behind, and packing up the treasured belongings you want to carry with you into the future.

Your old place, at Depression Lane, was a small and dim apartment without windows. For months or even years, you had no other choice but to turn left at the big intersection and drive back there every day after work.

Your new place is different. It’s bigger and has a nice view of the world outside. You worked really hard for it and it’s finally yours.

To get home after work, you need to turn right at the big intersection. Sometimes you forget and turn left. You don’t want to. You love your new place. It just happens. The left turn is so familiar.

Not until you’ve made enough right turns, the new route is automated. And you’re no longer at risk of driving back to Depression Lane out of old habit.

That process takes time.

That’s why your psychiatrist might encourage you to keep taking antidepressants for a full year, even if you’re symptom-free. And it’s why at the end of psychotherapy you spend considerable time on relapse prevention. It’s to put a roadblock on that left route until your brain automatically turns “right”.

As so often with depression, there is no 100% guarantee. Even with relapse prevention, depression might still happen. But prevention significantly lowers the risk.

Medication and psychotherapy, however, are not the only treatments which can prevent new episodes of depression.

There is scientific evidence to suggest that tDCS protects against depression relapse as well. And it can help you maintain the improvements you’ve made during treatment.

In 2022, Woodham and colleagues investigated the long-term effects of home-based tDCS treatment on depression. At a 6-month follow-up, 91.3 % of the participants had significantly improved and 73.9 % were depression-free. The treatment was safe and tolerable for all participants.

In 2019, Aparicio and colleagues found that tDCS treatment was safe to use long-term and effective at preventing depression relapse during a 6-month period. They noticed that two weekly tDCS sessions seemed more effective at preventing relapse than only one.

In the light of new scientific evidence, Flow Neuroscience’s team of clinical experts have created recommendations for long-term use of the Flow tDCS treatment.

These recommendations have been reviewed by a scientific board, including Professor of Psychiatry at King’s College London, Allan Young, and leading researcher in neuromodulation at the University of São Paulo, André Russowsky Brunoni.

How to use Flow to treat depression and lower the risk of relapse in 4 steps

Let’s begin with a short summary – a 4-step guide to the recommendations. And a more detailed explanation will follow after.

Step 1: Complete 5 stimulation sessions a week for 3 weeks.

Step 2: Complete 2 sessions a week for another 7 weeks.

Step 3: Evaluate – Is the Flow treatment helpful for me?

(You’ll find out how to answer this question in the section called Exactly how do you use the Flow treatment beyond 10 weeks?)

Step 4: If Flow is helpful, continue with 2 weekly sessions for another 6-12 months. This may prevent depression relapse and maintain your improvements.

How does depression relapse work?

According to current research on depression relapse, everyone has a heightened risk of relapse during the first 6-12 months following treatment. However, depression relapse can also happen during the course of a lifetime.

For around 50% of people who undergo depression treatment, depression appears as a one-time disorder which can be cured. For the other half, depression manifests as a recurrent disorder with periods of temporary recovery (remission) and relapse – similar to asthma or lupus.

These facts may not be particularly uplifting. But knowledge is power. Knowing how depression works places you in a much better position to manage it.

After a period of being symptom-free, you may start to notice depressive symptoms re-emerging. You may experience a low mood and a loss of interest in the things you usually enjoy. Perhaps negative thoughts and feelings refuse to leave you alone. If the symptoms persist for more than 14 days, they could indicate a depression relapse.

Please remember that even if your depression is of the recurrent kind, each episode is treatable. And since depression is usually more easily treated at an early stage – the sooner you start your treatment, the better.

Keeping a Flow headset at home allows you to begin immediately, as soon as the first symptoms appear. If a relapse occurs, reset your stimulation schedule in the Flow app and start your depression treatment from the beginning with 5 weekly sessions for the first 3 weeks. After the initial 10 weeks of treatment, continue for another 6-12 months.

Who is at risk of recurrent depression?

Researchers are still uncovering the causes behind depression relapse. Sometimes, difficult life experiences or seasonal changes trigger a relapse. Other times, depression seems to recur out of nowhere.

Currently, it’s unclear why some people experience depression as a recurrent disorder and why others only have one episode during their lifetime.

So, the frustrating truth is: everyone is at risk of depression relapse. And everyone would therefore benefit from relapse prevention.

Now, let’s go into more detail.

There are a few well-known risk factors which put people at higher risk of relapse. Note, their presence in your life is not a guarantee of relapse, they just represent an increased risk.

People with a heightened risk of relapse are recommended to stick to their Flow treatment for a longer period of time – 12 months after the initial 10 weeks of treatment (provided, of course, that the first 10 weeks have been helpful).

People with a low risk of relapse are recommended a minimum of 6 months treatment after the initial 10 weeks. Even though they’re not at high risk, everyone is vulnerable to relapse during the first 6 months following depression treatment.

So, how do you know if you are at high risk of relapse or low risk?

We can never know for sure, but if you recognise any of these risk factors, you are recommended to continue your Flow treatment for 12 months.

Risk factors

1) You have experienced childhood maltreatment (such as physical, emotional or sexual abuse, physical or emotional neglect, family conflict or violence).

2) You experience lingering symptoms from your last depressive episode (you were never fully recovered). Such lingering symptoms can intensify and “reactivate” depression. That’s why it’s important to continue your treatment until all depressive symptoms are gone.

3) You have a history of prior depressive episodes.

4) You have other chronic physical or mental health disorders.

5) You experience both depression and an anxiety disorder.

6) You are prone to rumination – you experience repetitive negative thinking or easily dwell on negative feelings/thoughts.

Exactly how do you use the Flow treatment beyond 10 weeks?

The large scale Empower trial as well as Flow Neuroscience’s real-world data (based on over 16 000 Flow users) indicate that 90 % of the improvements people see with the Flow treatment usually occur within the first 10 weeks. And that continued usage enables people to maintain their improvements long-term.

So, the first 10 weeks of stimulation will give you a good indication of whether the Flow treatment works for you. If it helps you, we recommend that you continue.

After 10 weeks of treatment, use the following 3 scenarios to evaluate how to continue with Flow:

1) Your depression score in the Flow app drops to minimal depression (below 12 points) within your first 10 weeks.

Recommendation: Continue to use the Flow treatment twice a week for another 6-12 months to help maintain your positive results and prevent relapse.

As mentioned above, if you recognise any of these risk factors, you are recommended 12 months treatment after the initial 10 weeks:

  • Childhood maltreatment
  • Lingering symptoms from your last depressive episode
  • A history of depressive episodes
  • An anxiety disorder
  • Other chronic physical or mental health disorders
  • Frequent repetitive negative thinking

2) Your depression score in the Flow app improves significantly, but you still have depression.

Recommendation: Continue to use the Flow treatment twice a week for another 6-12 months to help maintain your positive results.

So, what does “significantly improved” mean?

Ultimately, you are the person to decide if the treatment is helpful or not. But here are some examples of significant improvement:

  • Your depression score drops by around half.
  • Your score improves from severe depression to moderate/mild, or from moderate depression to mild.
  • You experience that the Flow treatment is helping you to manage your depression.

If this scenario applies to you, you may also want to consider the following solutions:

  • Combine the Flow treatment with another evidence-based solution such as psychotherapy or antidepressant medication. tDCS research suggests that combining tDCS with antidepressants makes both treatments more effective.
  • Practise evidence-based lifestyle changes to further improve your depression.
  • You may benefit from an individualised stimulation protocol with more frequent sessions. For safety reasons, the stimulation schedule can only be altered together with a qualified clinician who is able to assess your unique condition and monitor your treatment.

The stimulation protocol can be tailored by your current doctor via the Flow Clinician Portal free of charge. To initiate this process, ask your doctor to email Flow Neuroscience at support@flowneuroscience.com and request access to the Flow Clinician Portal.

Another option is to contact a clinic with prior experience of the Flow treatment.

3) Your depression score in the Flow app does not improve within your first 10 weeks.

Recommendation: Usually, the biggest improvements occur within the first 10 weeks. If you haven’t noticed an improvement at this point, Flow may not be the right treatment for your depression.

There is no treatment that works for everyone, but there are more than one option. Contact your clinician to discuss other solutions.

Perhaps this list of 14 depression treatments can help you.

Are there any health risks to using the Flow treatment for 6-12 months?

There are no health risks associated with the technology used in the Flow treatment – tDCS. On the contrary, research participants have used the same tDCS technology for 6 consecutive months without any changes in side effects. That is a good indication of long-term safety. The research trials include Woodham (2022), Aparicio (2019) and Valiengo (2013).

In addition, Flow Neuroscience’s long-term recommendations have been reviewed by a board of distinguished scientists, including Professor of Psychiatry at King’s College London, Allan Young, and leading researcher in neuromodulation at the University of São Paulo, André Russowsky Brunoni.

That’s why Flow Neuroscience can confidently recommend their treatment for up to 12 months. Especially since the risk of depression relapse is heightened during that period.

However, we must always consider that research is performed on groups of people, not individuals. So, we can never perfectly predict how the treatment will affect you as a unique individual with your unique health profile.

Should you notice any considerable changes in side effects during your 6-12 months with the Flow treatment, contact the support at support@flowneuroscience.com. You should also speak to a clinician and consider discontinuing the treatment.

What happens if you continue the treatment beyond 12 consecutive months?

The recommendations are ruled by science and created to ensure your safety. So far, no research participants have been followed beyond 12 months. Consequently, it’s unclear how tDCS affects the brain after several years of stimulation.

The researchers don’t expect long-term tDCS to be harmful. There are no indications of that. They simply don’t fully know at this point.

There are Flow customers who have used the Flow treatment for over 3 years without noticing any changes in side effects. However, before this type of usage is studied in controlled research trials, it’s impossible to predict the effect for large groups of people.

If you want to use the Flow treatment beyond 12 consecutive months, the best solution is to contact a clinic or another mental health professional who can assess your individual condition and monitor your treatment.

Your current doctor can easily be granted access to the Flow Clinician Portal where they can remotely monitor your treatment and progress. To initiate this process, ask your doctor to email Flow Neuroscience at support@flowneuroscience.com and request access to the portal. This is free of charge.

Can relapse happen even if you stick to the Flow protocol?

Unfortunately, yes. Even though the Flow treatment can help lower the risk, relapse can still happen.

Depression is a severely complicated disorder with multiple causes. Biology, psychology, environment, hormonal fluctuations, stress, lifestyle factors, social and cultural factors all play a role in the development of depression. There is currently no depression treatment which can control all of those factors.

So, even if you do everything in your power to prevent depression, it may still come back. That is not a reflection of you or your treatment. It’s the nature of depression.

But remember, even if you suffer from recurrent depression, each episode is treatable.

Read more about how to understand and prevent depression relapse here.

For questions, please contact support@flowneuroscience.com.

Hanna Silva

Clinical psychologist at Flow Neuroscience

December 2023