When Kate Alexander-Dobrovolskaia and Dmitry Shishkin lost their only child, Masha, to a rare cancer in the spring of 2022, their entire world imploded.

Only 23 and 22 when Masha was born, they'd been like 'best friends growing up together'.

'We never wanted more kids; the three of us were such a perfect balance,' Kate says. 'We were unbelievably happy.'

Masha, a student at King's College, London, was beautiful and empathetic. A natural communicator, her podcast YungMash Radio had a devoted following of fellow teens and twenty-somethings, all navigating the ups and downs of young adulthood. Masha talked about whatever was on her mind, whether it was dating, therapy or her cancer experience.

At the age of 19, she was just hitting her stride when she was diagnosed with a 27cm tumour in her pelvis. Surgery, followed by 28 rounds of chemotherapy and an experimental immunotherapy drug could not stop it spreading.

Throughout her gruelling treatment, Masha used the time she had to support her growing online community. 'She was determined to make the absolute best of the absolute worst,' Kate says.

'To be as kind and caring as she possibly could be,' Dmitry adds. 'We would go to bed at night listening to laughter from the floor below, where Masha was hosting a Twitter space for hundreds and hundreds of other kids, for laughs and conversation and mutual support.'

On Mother's Day, 2022, barely two weeks after Masha's death at 21, the couple attended a candlelit vigil for her in Hyde Park, organised by young people from all walks of life who'd followed her on Instagram and Twitter and who wondered how they would cope without her.

'Some of these young people had no support and no one to look up to – they were bound together by the groups Masha held online, where they felt held and supported,' says Kate. 'I knew I couldn't walk away from them.' Kate, 47, and Dmitry, 46, CEO of a media company, have now poured 'all the love and energy and thought that would have gone into Masha's care and the care of our future grandkids' into creating a supportive online community in her name.

'Being Masha's friend, being loved by Masha, it was like having the sun all to yourself,' Kate says.

The YungMash (Masha's nickname) Collective, a free online mentoring community for young adults, based on cutting-edge neuroscience, was launched on what would have been Masha's 22nd birthday in July 2022.

'They talk about their problems at home and generational or cultural gaps within families, their romantic relationships, money and work concerns,' says Kate.

'But this isn't a place to wallow. It's a coaching group, a place to change perspectives and empower each other.'

The support is provided by their peers – groups of young adults, 'yung mentees' – who attend weekly group sessions led by 'yung mentors' who have already completed a mentor course, with coaching delivered by a network of seven qualified global neuro coaches. Each mentor training course involves 24 hour-long sessions, held weekly online and covering subjects such as brain structure and how memory works, as well as providing evidence-based tools – including mindfulness, a technique similar to meditation, and yawning.

If the latter sounds unlikely, in fact studies have shown it can stimulate memory, focus and attention. 'These techniques help shift a person out of a stressful or anxious or angry or upset state into a calm and reflective one, where you can observe a challenging situation and make rational decisions,' Kate explains.

She is clear that YungMash is not offering counselling in the traditional sense of the word. 'This is not emergency mental health.'

In the 40 years since the first research on meditation and mental health, there have been thousands of studies showing its effectiveness in reducing anxiety, especially in times of extreme stress.

These include brain scan studies at the University of Pennsylvania in 2006, carried out by the neuroscientist Dr Andrew Newberg and researcher Mark Waldman, which identified two areas of the brain that are stimulated by mindfulness and other forms of meditation, now known as the salience network (SN).

Since then, over 200 different networks have been identified on brain scans – with researchers focusing on three: the central executive network (CEN), involved with conscious decision-making; the default mode network (DMN) (imagination and creativity); and the salience network, which plays a crucial part in regulating emotion and developing social skills such as empathy and compassion.

Mark Waldman, one of the seven global neuro coaches, or Yung Masters, who are all giving their expertise free, explains how the practice of mindfulness works.

'When you deeply relax and become aware of the thoughts and feelings that are constantly flowing through your mind, you immediately interrupt the worries, fears, doubts and uncertainties that are being generated by the most imaginative part of your brain – the default mode network,' he says.

'Virtually all our psychological problems – anxiety, stress, worry – are to do with spending too much time in this network. By first watching how your mind wanders and jumps about, and then focusing your attention on present-moment experiences, you stimulate a third area – your salience network. This is your inner therapist.'

Over Zoom from his home in California, Waldman, who spent decades teaching his techniques to high-flying executives running multi-million-dollar companies, takes me through some of the exercises, such as mindful yawns (it's the same, just deliberate) and super-slow head circling.

'Using these evidence-based strategies for a few seconds several times an hour can result in a profound shift in your mental state,' Waldman says. 'But you need to do it every day.'

Another of the global neuro coaches is Australian psychologist Michael Kirton, who specialises in child development, mental health issues and trauma. Kirton believes mindfulness and particularly gratitude journalling – noticing things you're grateful for and writing them down – can have a significant impact.

In physiological terms, 'the neurons [nerve cells] in the brain related to gratitude reflections – thinking about the good stuff – develop longer axons [the 'threads' that connect them], sometimes by a factor of three,' he says. The exact significance of this is not clear, but 'in my clinical experience, the outcomes – life satisfaction, happiness and emotional balance, far outweigh the effort and time expended'.

Scientific evidence backs this up: a review of 64 trials looking at gratitude journalling, published in the journal Einstein last year, demonstrated that patients who practised gratitude journalling experienced a more positive mood and emotions, and reduced anxiety and depression.

'Similarly, by yawning and stretching several times a day, I can say conclusively that if you do it regularly, your life will change,' says Kirton.

'The key to optimal psychological health is to interrupt the imaginative part of your brain, the part that says, what if this happens? Or how will I deal with that?'

This is central to the work of YungMash, says Kate: 'One of the problems we are facing everywhere in the world is the levels of anxiety young people are experiencing.

'As a result, they are finding it hard to commit in relationships, whether personal or professional. It is also making them unattractive for employers, which is troubling both for them, as they are having to move back with their parents, and is equally troubling for companies, who are finding it extremely hard to engage Gen Zs [born 1997-2013]. In creating the Collective, we wanted to help this generation see just how easy it is – and it really is – to get out of that mindset and live much more satisfying lives.

Cameron McBride, 24, a Yung mentor, was diagnosed with ADHD, anxiety and depression at university. He joined YungMash in June 2022.

'I was having panic attacks every day; I was at zero,' he says. 'I wasn't ready to try counselling but I was interested in neuroscience and I was ready to help myself.

'The most important thing about the Collective is that you have to be the driving force of your change.

'It's still extraordinary to me how effective a simple slow stretch and a yawn is,' he adds. 'The tools are really easy, building the habit and remembering to use them before you're spiralling is the hardest part.'

Two years on, he's completed his studies at the University of Birmingham, is interviewing for his first engineering job and is in a stable relationship.

Georgiana Penciu, 33, a dental assistant from South London and YungMash mentee, joined in 2022. 'I was plagued with anxiety and self-doubt,' she says. 'I constantly felt that I was the problem – it was my fault I wasn't achieving anything and I didn't deserve happiness. But I've now shifted from a defeatist 'I can't do it' mentality to a productive 'how can I do it' approach.'

Before her cancer diagnosis, Masha helped her mother in her business, coaching people to believe in their potential.

'Mash was my right-hand woman and my absolute best friend,' says Kate. 'We were always together.'

Then, late in 2019, Masha started complaining of pain in her left hip and difficulty emptying her bladder. Just before Christmas, an MRI scan revealed a 27cm tumour in her pelvis.

Kate cries describing the unbearable lows of Masha's treatment – and the devastating news delivered by insensitive doctors who couldn't meet her eye. 'Masha was just 19 years old. No one asked if she was ready to hear she was dying.'

But there was also kindness and connection. 'When we went into hospital for chemo, Masha and I had so much fun,' Kate says. 'We had fairy lights, tea and cake, nice plates, duvets and pillows. We made it a mini home. She knew all the nurses' kids' birthdays and she'd make them presents. It was as special as it could be.'

Kate used the YungMash strategies, 'a five-minute stretch and yawn and a hand rub to ground ourselves', every time Masha had to go into hospital for treatment.

'My world was collapsing. I cannot describe the dread and the fear,' she says. 'In order to survive that, we had to find a way to do it calmly, with grace and a smile.'

Masha had eight rounds of chemotherapy, followed by surgery in July 2020 to remove the tumour then more chemotherapy. 'That year, she lived her best life,' Dmitry says. 'She never said "Why me or poor me". She'd say, "We don't know how many days we have so we have to do something to make every day special". When we cooked together, we always used the best china. Everything had to be beautiful.'

Masha's tumour – so rare there are only 17 other documented cases in the world – could not be beaten. Yet even on the day she died, the couple came home from hospital and wrote in their gratitude journal: 'We were lucky to be with her to the end and she is now pain-free.'

They are conscious that, barely two years after Masha's death, they are mired in the deepest grief. 'It's absolutely the worst,' Kate says. 'Even in her final hours, we couldn't know how bad it would be.'

Masha's school, Ibstock Place in Richmond, south-west London, where she was head girl, introduced a 'kindness award' presented to one teacher and one pupil every year.

'Masha completed what she was meant to do on Earth,' Kate says. 'But it really doesn't make it easier. We miss her so much.'

Every day without their much-loved girl takes concentrated effort. 'The only thing you can do to survive is be someone else's sun. Just shine for someone,' says Kate. And talking to the 50 young people who have already been through the course, and seeing the difference it's made, makes her heart sing.

'These young people were not in each others' lives a year ago. They are now a community based on care and love – and it's an absolute delight,' she says. 'Dmitry and I are so proud of them all. For as long as we are here, we will carry on planting seeds, giving young people enough love and confidence to fly.'