What is the Calm Harm app?

The Calm Harm app powered by stem4 helps young people resist or manage the urge to self-harm. Developed by Dr Nihara Krause, a Consultant Clinical Psychologist, together with ideas from young people, Calm Harm uses strategies from Dialectical Behaviour Therapy (DBT) to help users learn to identify and manage their ‘emotional mind’, teaching impulse control, emotional regulation and tracking underlying triggers to harmful urges.


It is not a substitute for a mental health professional.

Who is Calm Harm for?

Calm Harm is recommended for the ages of 13 years and above. If a younger child would like to use it, it is recommended that this is done under the guidance of a responsible adult.


Please note that Calm Harm is not a substitute for assessment and intervention by a mental health professional. It is recommended a GP should be consulted in the first instance.

How does Calm Harm work?



‘The urge to self-harm is like a wave – it feels most powerful when you start wanting to do it. Once you surf the wave, the urge will fade.’


Users can learn to ‘surf the wave’ by doing five or fifteen minute activities in these categories:

∙ Distract helps to combat the urge by learning self-control

∙ Comfort helps to care rather than harm

∙ Express gets those feelings out in a different way

∙ Release provides safe alternatives to self-injury

There is also a breathing technique to help reduce symptoms of stress and anxiety.


Calm Harm educates using strategies from evidence-based Dialectic Behaviour Therapy (DBT). DBT has been shown to be an effective treatment for some groups of patients who self-harm.

The focus is on helping the user learn to identify and manage their ‘emotional mind’. The app teaches children and young people impulse control, emotional regulation and tracks underlying triggers to harmful urges. It also helps self-monitor and signposts to help.



More detail


Calm Harm gives users some immediate techniques to help break the cycle of self-harm and explore underlying trigger factors. Self-harm is an impulsive behaviour and immediate access to support is needed to regulate an impulse. It is a key risk factor in suicide and is habit forming.


DBT is a therapy that is evidence based for impulse control and emotional regulation. Apps on handheld devices are available immediately and can be used in private to help urge reduction and to reduce frequent behaviour. Calm Harm provides a sense of control to deal with problems, helps self-reflection and increases motivation to ask for help.

What were the aims of developing Calm Harm?

To develop an evidence-based, widely accessible digital tool to help young people (13 years and over) manage the urge to self-harm (younger with parent involvement).


To be universally acceptable – It can be helpful for young people who are unlikely to accept traditional treatment, whose behaviours do not meet the threshold for help, are waiting for treatment or alongside treatment.


To devise an anonymised analytical model to evidence effectiveness and inform future development.


To comply with NHS information governance requirements to facilitate publication on the NHS Apps Library.


To raise the profile of stem4 and its work to support teenage mental health.

What evidence is there that Calm Harm works?

Pilot study:


The model of the app was developed according to Dialectic Behaviour Therapy principles by an experienced consultant clinical psychologist and a group of 8 young patients who self-harmed provided feedback and tasks. This group then was expanded to 14 young people aged between 15-17. At baseline the severity and frequency of self-harm behaviour was noted and the Moods and Feelings Questionnaire and the Strengths and Difficulties Questionnaire completed. They were given Calm Harm to use in-between weekly treatment meetings with a clinical psychologist. Familiarisation (did they want to use the app) and safety (triggers, crashes) was assessed at two weeks and measures were repeated at 4 weeks. Statistically significant results on depression were noted post use. Free answers indicated 84% reduction in self-harm in between appointments. Acceptability was high at 99% and safety was also high 99%. The most popular category was comfort and the most common reason for self-harm was ‘I was sad’.


A clinical study is pending – we are currently having discussions with a possible research partner.


Analytics from the app:


In order to evidence the effectiveness of the app, the following data is collected:

  • Number of downloads and Number of users (on both iOS and Android)
  • Data submitted on installation of the app (optional) including: Gender, Age Range, Location, whether they have sought professional treatment
  • Aggregated data on user activity and its effectiveness
  • Analytics on user journeys


As of 1 April 2019:

Calm Harm has been downloaded over 920,000 times.


93% of Calm Harm users reported a reduction in the urge to self-harm after completing an activity.


As a more accurate figure of who the app has ‘supported’, we use the number of returning users i.e. those that have used the app more than once to manage their urges. At 63.7% there are 512,605 returning users.


93%** of users have reported a reduction in the urge to self-harm after completing an exercise and so we can estimate, based on these figures that the newly designed app has supported at least 476,723 people to resist or manage the urge to self-harm.


25% of the user base is located in the UK which demonstrates we have supported at least 119,181 individuals with their urge to self-harm in this country. Of these, based on the trends around anonymised data capture, we estimate that the highest proportion of these are teenagers (72,700).


** This 93% efficacy rating is much higher than anticipated especially when reviewing internationally renowned health apps such as Sleepio who claim a 75% efficacy.


Calm Harm has met NHS governance requirements to be included on the NHS Apps Library

Do you involve users in your app?

We worked co-collaboratively with young people to develop Calm Harm. The co-collaborative workshops with young people explored desired outputs, user journeys, visual concepts, security/privacy, user experience, and tone of voice.


We use the information given to us in our work with young people in schools to update the app as well as feedback from users of the app.  Many of the updates tasks are from users.


stem4 consistently monitors user feedback via emails, social media and reviews on the App Store/Google Play.

What safety features are present?

Users wanted an app with a small digital footprint that was private. No personally identifiable data is collected.


Users are given the option of setting a passcode. However, since no email address is taken if the passcode cannot be remembered we are unable to help reset it. Users are notified of this when setting the passcode.


Whilst some of the tasks are helpful for some users, others may be ‘triggering’ for others. We have therefore provided the option for users to hide particular activities they might find triggering in order to personalise the app for their safety.


When the urges remain high, a message is generated on the log which suggests the user sees a medical professional.


Users are signposted to National resources and emergency numbers.


The app has undergone a clinical safety assessment by a clinician, which was overseen by an experienced clinical safety officer within a NHS Digital Development Lab.


A hazard log is maintained and regularly updated. Any concern is responded to within allocated periods of time.

How often do you review/update Calm Harm?

Calm Harm is reviewed and updated every three months to ensure the app is clinically valid.


The clinical risk is monitored and laid out in the hazard log and map to the DCB 0129 guidelines. A flow chart of hazard mitigation and response is available. This outlines how issues will be addressed together with target response times.


Our target response time for urgent issues is 24 hours, for high priority issues 72 hours, medium priority 7 working days and low priority 14 working days.

What data do you collect & store?

Calm Harm does not collect any personally identifiable information. Anonymised data such as most used tasks, whether each task helped reduce the urge, etc. is collected to ensure the effectiveness of the app can be monitored.


Calm Harm is an app that can be used on IOS or Android. The content is downloaded the first time the user opens the app and then cached. It can still be viewed and used offline.


All data collected via the app is aggregated and cannot be tracked to each user/device. However, the security of this data is still important to us and as such, we will take all steps reasonably necessary to ensure that the data is treated securely. The transfer of data is encrypted over a secure connection (SSL). You can read our full Privacy Policy here.


App data is stored using Amazon Web Services (AWS) which has certification for compliance with ISO 27001:2013 – https://d1.awsstatic.com/certifications/iso_27001_global_certification.pdf.


Clinical risk is managed by having a contractual agreement with the developer that data security and technical risks will be addressed at every update or when concerns are raised via the clinical safety system which indicates clear timeframes and the flow of what action will be taken.


The app is stand-alone and does not interact with existing enterprise systems.


It has been designed with young people to ensure data and device memory/data use in their preferred device (smartphone) is not compromised.


Activity is logged to present the user with the following information:

  • Average urge strength (past 7 days)
  • Most active time of day
  • Interactive self-monitoring graph indicating most common urges
  • Activity log
  • Most used activities


In order to evidence the effectiveness of the app, the following data will be made available:

  • Number of downloads and number of users (both iOS and Android)
  • Data submitted on installation of the app (optional) including: Gender, Age Range, Location, Whether they have sought professional treatment
  • Aggregated data on user activity and its effectiveness
  • Analytics on user journeys
How do I report an issue with the app?

To report an issue with Calm Harm please email calmharm@stem4.org.uk.


stem4 endeavour to respond to the enquirer according to our target response times. Risk will be amended with immediate effect. Amendments to the workings of the app will be made at every update.

What design standards were followed?

NHS Digital DCB0129 standards.


Also our app developers:


Design with Users Needs – our workshop helped us to identify these.


Design with Data – we used the existing stem4 app data, (e.g passcode consideration) as well as ongoing updates based on the Calm Harm analytics.


Iteration – New updates depending on things that have (or haven’t) worked or new functionality.


We also do strive to be as broadly accessible as possible through the use of industry best practices. For example, contrast colours for those with sight issues, using a font that’s clear to read etc.




Calm Harm has met NHS governance requirements to be included on the NHS Apps Library.


Calm Harm is licensed by Leeds City Council for young people using the Leeds Mindmate services.


“I had a young person who was referred to the service, who said that her reduction in self-harm was due to using your app. Whenever she felt the urge to self-harm she would open the app and use the distraction techniques provided. I have had a look at your app and downloaded it to have a look myself, it would be great to tell the young people who are referred to the programme about it, and if they wish they can download it.”

Project Co-ordinator for Breaking Silence

A programme for young people and their families affected by self-harm.

stem4 is a charity that relies on your support to be able to continue supporting teenage mental health. If you would like to make a donation, you can do so below:

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