Marissa Smith appears to enjoy the sort of life many women aspire to. The 35-year-old divorcee lives mortgage-free in a cottage in Essex, where roses climb the garden fence and her eight-year-old son attends a sought-after Church of England primary school nearby.

She drives a nearly new Golf GTI, spends summers in Spain where her mother owns a second home, and fills her mornings with gym classes and errands before the afternoon bustle of the school run, homework and bedtime stories.

Divorce from her banker husband was difficult – yet left her financially secure enough to step back from her career in marketing and devote herself fully to raising their son.

To the other mothers gathered at the school gates Marissa must seem composed and healthy.

Few would suspect that behind the designer activewear, chats about holidays and sports day plans, she has a secret cocaine problem she has spent years trying to conceal.

Marissa first experimented with the class A drug in her late teens but says she gradually lost interest after meeting her future husband. By the time she married, at the age of 26, settled into family life and became pregnant with her son, cocaine barely crossed her mind.

‘I just grew out of it,’ she says. ‘I was busy and focused on being a good mum.’

But after separating from her husband three years ago and beginning a relationship with a new boyfriend six years her junior, the drug reappeared in her life. ‘He always seemed to know someone who had it,’ she says. ‘At first it was occasional – a fun thing on nights out when I didn’t have my son. Then gradually it became more normal.’

Now, on the evenings her son stays with his father, another version of Marissa emerges.

Dinner dates become after-hours drinks. There are hushed conversations huddled in bathroom cubicles and lines of cocaine lined up on polished kitchen counter-tops.

Britain is currently in the grip of a middle-class cocaine crisis – and women, it seems, are increasingly caught up in it

An estimated 8.7 per cent of adults aged 16 to 59 – about 2.9 million people – used illegal drugs in the past year 

‘There’s this instant rush,’ she says. ‘Suddenly I feel brighter, more confident, more interesting. I can talk for hours and feel completely on form socially.’

Unlike wine, she insists, cocaine leaves her less incapacitated the following day – outwardly, at least.

‘With alcohol you wake up bloated and obviously hungover, and I have a child so I can’t really hide in bed all day,’ she says.

‘With cocaine it feels different at the time, not messy like having too much to drink. You feel sharper, more alive.’

The drug offers her an escape from the pressures of motherhood and keeping up appearances.

But the morning after, reality hits. Unable to sleep and still jittery, Marissa finds herself on the school run with a pounding heart and creeping sense of dread.

‘The crash is horrible,’ she admits. ‘You feel anxious, ashamed and completely depleted, but you still have to make packed lunches, chat to other parents and get through the day pretending everything’s normal.’

She describes sitting on park benches during playdates, struggling through small talk while internally counting the hours until bedtime.

‘You become obsessed with appearing normal,’ she says. ‘I make sure I look put together, because I’d be mortified if the other mums found out. Most of my female friends have absolutely no idea. They all look so together and wholesome, and meanwhile I’m standing there feeling utterly unwholesome inside.’

As disturbing as her story may seem, Marissa – who agreed to speak under an assumed name – is far from an isolated case.

Britain is currently in the grip of a middle-class cocaine crisis – and women, it seems, are increasingly caught up in it.

An estimated 8.7 per cent of adults aged 16 to 59 – about 2.9 million people – used illegal drugs in the past year, according to the Crime Survey for England and Wales.

While drug use among younger people has fallen sharply since the late 1990s, rates among older adults have remained high. And when it comes to cocaine, affluent households appear to be driving demand.

Office for National Statistics data shows people in higher-income households are roughly twice as likely to take class A drugs as those in lower-income groups – with powdered cocaine by far the most commonly used.

Meanwhile, the number of women seeking treatment for cocaine problems has risen dramatically over the past decade.

Experts say much of this use is hidden behind outwardly respectable lives – among professionals, mothers and women attempting to balance careers, childcare and the pressure to appear endlessly productive. Just like the celebrity cook and mother-of-two Nigella Lawson, who admitted in 2013 to taking cocaine and cannabis during difficult periods of her life.

The ‘Domestic Goddess’, who denied being addicted, told a court she had used drugs because she ‘found it made an intolerable situation tolerable’.

Addiction specialist Professor Ian Hamilton says cocaine addiction among middle-class women may be far more common than many people realise.

Celebrity cook Nigella Lawson admitted to taking cocaine and cannabis during difficult periods of her life

The ‘Domestic Goddess’, who denied being addicted, told a court she had used drugs because she ‘found it made an intolerable situation tolerable’

‘When people think of drug addicts, they often think of homeless people, or those living on the edge. But the majority – particularly with drugs like cocaine – will actually be functional addicts who are able to hold down a job and maintain relationships,’ he explains. ‘Their addiction won’t force them into debt, so from the outside things can appear totally normal.’

The difficulty with cocaine in particular, says Professor Hamilton, is that many women do not realise how quickly occasional use can tip into addiction.

‘Cocaine is one of the drugs to which you develop a dependency the fastest,’ he says.

‘With alcohol, it can take years to become addicted, but with cocaine you only need to use it a few times before the body and mind become dependent.’

Cocaine is a stimulant drug, and even small amounts can cause a rapid heartbeat, palpitations and irregular heart rhythms. It also increases the risk of seizures and stroke, and experts say there is no ‘safe’ amount.

Purity also varies widely, with cocaine often mixed, or ‘cut’, with other dangerous drugs.

However for Selina Harper – also not her real name – and her social set, it’s seen a bit like ordering a nice espresso.

She lives with her husband and two children, aged three and six, in a £2.2million detached house in a prosperous commuter village. Their children attend private school, and family holidays are spent in Cornwall or Greece. Weekends revolve around dinner parties, children’s birthday gatherings and drinks with other well-to-do couples from the area.

From the outside, the 38-year-old business owner enjoys all the trappings of Home Counties success: the luxury SUV on the driveway, the roomy kitchen that’s perfect for entertaining. It’s the kind of life that seems tailor-made to appear in carefully curated images on Instagram.

However, behind the dinner parties and immaculate lawn, cocaine has become an almost integral part of her friendship group.

‘It all starts innocently,’ she says. ‘Everyone is enjoying a drink, then someone mentions getting some in, and pops down to the village to pick it up.’

What unsettles Selina most is not the drug use itself, but how ordinary it has become.

‘No one even seems to think it’s unusual any more,’ she says. ‘It’s almost like ordering another bottle of wine or a double espresso.’

Recently, she says, cocaine was being openly taken at a children’s party while youngsters ran around nearby. Parents kept slinking off to the bathroom in pairs and threes, returning suddenly excitable and energised.

Selina says: ‘It was far too obvious. I think even the children’s entertainer suspected what was happening.’

Unlike the stereotypical image of addiction, Selina says cocaine use among her social circle is rarely chaotic or visibly destructive. ‘These are well-off, functioning people with careers, nannies, cleaners and lovely homes,’ she says. ‘That’s why nobody questions it.’

She says cocaine is often used to prolong evenings after heavy drinking, creating the illusion of renewed energy and confidence.

‘Cocaine sobers us up after several bottles of wine, makes us fun and chatty and gives us an immediate high,’ she says. ‘We feel on top of the world and confident – not like downtrodden, exhausted parents.’

But beneath the glamour and social bravado, Selina admits there are moments where the absurdity of it all hits her. Though she insists she uses cocaine only occasionally, she says she has increasingly begun questioning the culture surrounding it – particularly among parents.

‘When my youngest was little, there were moments afterwards where I’d think: what on earth am I doing?’ she says. ‘You look around these beautiful houses with children asleep upstairs and realise how bizarre it actually is.’

Annalice Argyle, 54, understands the contradiction better than most. Today, the mother-of-one runs TRAC UK, a charity supporting people recovering from drug and alcohol addiction, with a particular focus on women’s recovery. But for years she battled cocaine addiction alongside nursery drop-offs and being a working mother.

A wealthy partner introduced her to the drug in her 20s, and funded her habit as it descended into dependency.

‘I would put my child in nursery, and that’s when I began taking cocaine,’ she says. ‘I picked a nursery where I could drop and run without too many questions.’

Sometimes, she says, she would spend the entire day using the drug, taking ‘the last line about an hour before’ collecting her son.

Like many women interviewed for this article, Annalice became consumed by the fear of being found out.

‘I was so worried the other parents would notice I was high,’ she says. ‘I would avoid eye contact, stay away from people and make excuses to leave quickly.’

The secrecy, she says, became exhausting. And over time, the physical effects are difficult to disguise.

‘You plan your whole life around hiding your addiction,’ she says. ‘It wasn’t long before I looked skinny and gaunt and my clothes started hanging off me.’

Annalice Argyle runs TRAC UK, having battled a cocaine addiction for years while also being a working mother

She also warns about the dangers of mixing cocaine with alcohol – something she says often accompanies middle-class social drug use. ‘The only way I could really come down off a cocaine high was with alcohol,’ she says. ‘I always used and drank – it was never separate.’

That combination creates cocaethylene – a toxic chemical produced in the liver when cocaine and alcohol are taken together – which experts warn significantly increases strain on the heart.

Now 17 years sober, Annalice says many women become trapped by the belief they are successfully hiding their addiction when, in reality, those around them are aware something is wrong.

For many women, particularly mothers, shame and fear can become major barriers to seeking help – especially when they have spent years appearing outwardly successful and in control.

Clare, a 46-year-old single mother-of-seven from Leighton Buzzard, Bedfordshire, understands that terrible situation all too well. For years she managed to maintain the appearance of ordinary family life while struggling with cocaine addiction.

‘Outwardly, I appeared to function normally,’ she says. ‘I worked, raised children and carried on with daily life, but behind closed doors it was chaos.’

She became adept at hiding the addiction from those around her.

‘You become very clever when you’re using cocaine,’ she says.

‘I used every trick in the book – pretending allergies were causing me to sniff all the time, and claiming that running around after the kids was why I was losing all that weight.’

But eventually the emotional strain of sustaining the deception became unbearable.

Today, Clare, who asked us not to print her surname, has been sober for more than seven years after finding recovery through a 12-step programme.

First developed by Alcoholics Anonymous and later used by groups including Narcotics Anonymous, the programmes bring addicts together in regular meetings where they support one another to stay sober.

Since giving up cocaine, Clare has begun volunteering, running women’s recovery meetings, attending university and working as a coach. She is to train as a pastor for the homeless.

‘Recovery has completely changed who I am and the direction of my future,’ she says.

‘I feel incredibly blessed to still be alive today.’