IT was a week after stopping antidepressants in 2011 when Alyne Duthie first began experiencing the symptoms which would ultimate drive her to try to end her life.

"I was out with a friend and I started to feel this powerful sense of terror and agitation," says Mrs Duthie, now 60. "Every day became a nightmare. I spent every day within my living room trying to survive. I didn't eat, I didn't sleep, I rarely left my flat because I was agoraphobic.

"By the summer of 2012 I was having conversations with my son about ending my life, and I took an overdose that summer."

Mrs Duthie's experience is one of hundreds of Scottish patient accounts submitted last week to Public Health England's landmark inquiry into prescribed drug dependence.

It also comes as figures published this week revealed that a record 902,168 people in Scotland were prescribed antidepressants last year, and new research indicates that the percentage of patients who suffer severe and long-lasting withdrawal effects is much higher that previously estimated.

Mrs Duthie, from Braemar in Aberdeenshire, had first been prescribed antidepressants 30 years earlier to treat panic attacks and depression brought on as her marriage disintegrated during the late stages of pregnancy with her son. At first she said she felt relieved because it was "a chance to get some help", but as the years went on she was troubled by brain fog, weight gain, digestive and bladder problems, and fatigue. Periodically, she tried to come off the drugs only to become "jittery and unwell", subsequently reinstating them.

The Herald: Alyne Duthie Alyne Duthie

By 2011 she had had enough and slowly tapered herself off venlafaxine, also known as Effexor. Although she survived her subsequent suicide attempt, she ended up in a psychiatric hospital where antidepressants were reinstated along with benzodiazepines and Z-drugs - types of sedative. It took her another year to wean herself off the medication, but she suffered extreme - and lasting - side effects.

"I used to get this burning sensation deep within my brain, especially towards the end of the day. Even my thoughts started to hurt me.

"Within days of coming off them I started having severe tinitus, the kind that pierces your brain. I started having severe abnormal movements - my head, arms, and legs jerked constantly. To this day my head and my right arm still jerk occasionally. I would get boiling hot then freezing cold the next. I used to go around with cold packs strapped to my chest.

"Every sound was intolerable - even the sound of my clothes against my skin. I used to fear the sound of my fridge, and the birds singing outside. My balance was affected. I used to walk as if I had rubber legs. One of the worst symptoms I had was painful brain pressure which I still get to this day, though not as bad. It's no exaggeration to say this used to make me scream in agony. I don't know what my neighbours used to make of it."

The most severe phase lasted four months, but Mrs Duthie continued to endure disturbing daily symptoms for years afterwards. Ironically, the duration of her ordeal eroded the support she had from medical professionals who preferred to diagnose it as relapse, not withdrawal.

"The longer it went on the more inclined my psychiatrist was to believe it was the return of my original illness, and not the drugs," says Mrs Duthie. "This was by far the most terrible experience of my whole life. It far surpasses my original depression and anxiety. I didn't think I was going to make it, and that was in no small part due to the blinkered attitude of GPs and my psychiatrist."

The Herald: Latest ISD Scotland prescribing figuresLatest ISD Scotland prescribing figures

For decades, the prevailing consensus in psychiatry has been that the vast majority of patients experience only mild and short-lived side effects after discontinuing antidepressants, as long as they taper off them gradually.

In the past year, however, this has been loudly and increasingly challenged as petitions on prescription drug dependence at both Holyrood and the Welsh Assembly gathered hundreds of stories of patients who describe the "hell" of withdrawal and the long-term impact on their health. Last week, 158 of these personal accounts of patients coming off antidepressants, benzodiazepines, or both, were compiled and submitted to the PHE inquiry.

They include a husband who describes how his wife "has gone from being a normal functioning person, working and studying to being completely incapacitated". A former primary school teacher is left "bedridden with plates of food" while her partner goes out to work, while another patient describes how they have gone from working full-time to being unable to work at all and are now on the brink of losing their home.

These are the extreme cases, but a study published on Tuesday in the journal 'Addictive Behaviours' has led researchers to demand that UK and US guidelines on antidepressant withdrawal "are in need of urgent correction" after it found that 56% of patients experience withdrawal effects - half of them severe - and that it was "not uncommon" for these to persist for several weeks or months. These could include hallucinations, brain zaps, hyper-arousal, sensory disturbance, nausea, agitation, muscle spasms, imbalance and insomnia.

Their findings - in stark contrast to NICE guidelines that withdrawal effects are mostly mild and dissipate within one to two weeks - are based on a systematic review of 24 previous studies covering thousands of patients worldwide, dating from the 1990s to the present decade.

In Scotland, the number of antidepressant prescriptions issued annually has soared by 74% since 2007, while the number of patients is up 42%.

The authors - Dr James Davies of the University of Roehampton and Dr John Read, a professor of clinical psychology at University College London and Sweden's Institute for Psychiatric Drug Withdrawal - said the surge is partly due to patients being kept on the drugs longer, but they question how many of these patients are genuinely depressed and how many are simply unable to stop antidepressants.

They state: "The evidence set out suggests that lengthening use may be partly rooted in in the underestimation of the incidence, severity and duration of antidepressant withdrawal reactions, leading to many withdrawal reactions being being misdiagnosed, for example, as relapse...It is of serious concern that prescribed antidepressant medications are causing withdrawal effects that are often long-lasting and severe, and that this is not being recognised by current clinical guidelines and, by extension, prescribers."

It is hard to grasp just how controversial such suggestions are within psychiatry, but a recent illustration of just how explosive the debate around antidepressant withdrawal has become was the resignation in September of Professor David Baldwin from PHE's expert panel on the issue. Prof Baldwin - who represented the Royal College of Psychiatrists - said he had been plagued by abuse and harassment online from opponents who accused him of being in the pocket of pharmaceutical companies and a "pharmaceutical rapist and a lying serial murderer worse than Hitler".

Prof Baldwin had come under attack after downplaying the side effects of coming off antidepressants in a letter to the Times in February, and accused Prof Read - his colleague on the PHE expert panel - of fanning the flames, something Prof Read has strongly denied.

The Herald: Dr Peter GordonDr Peter Gordon

Dr Peter Gordon, a consultant psychiatrist from Bridge of Allan, knows first-hand how hard it be to speak out about withdrawal. He was prescribed the antidepressant paroxetine in 1998 for social anxiety and sleep disturbance, but ended up in hospital with psychosis and undergoing electro-convulsive therapy (ECT) when he later tapered himself off it over an 18 month period.

"It was so severe I was hospitalised in a psychiatric unit," said Dr Gordon, who now works as an old age psychiatrist in NHS Lothian. "I was tried on various medications and eventually I was put back on Seroxat and, quite frankly, I'm scared shitless to try and come off it now."

Despite his own experience, he was reluctant to raise the issue with colleagues and feels there is a widespread "head in the sand" attitude to the potential scale of the problem.

"I found it extremely difficult and for many years I just didn't talk with my colleagues about it because I just knew I wouldn't be believed, I would be seen as less credible and when I've raised it in meetings I've not had a good reception.

"If I had that problem revealing my experiences and learning over time, what might patients have?

"I'm not a pill-shamer. I'm not anti-medicine. I'm not anti-psychiatry. I'm a questioning psychiatrist. The evidence we've got insufficient to explain this so we should be listening to the evidence of the many people who have been brave enough to come forward now.

"I think it will take another ten years to know the scale of this issue but I think it's much, much bigger than psychiatry ever wanted to acknowledge it to be."

Laura* [not her real name] is also among those whose testimonies formed part of last week's Scottish evidence to the PHE.

The 35-year-old from the Highlands was put on Zoloft aged 17 after struggling with shyness and lack of confidence at work. After a year she weaned herself off but within a week began experiencing overwhelming adrenaline rushes and a "feeling of doom".

She said: "Before I was on the drug I had anxieties about not being very good at things at work, but when I came off the drug the anxiety was so severe I couldn't do anything at all. I went back on the drug because it was just desperate."

After close to 15 years on sertraline, Laura asked her psychiatrist to switch her onto Prozac in the hope that she could finally stop antidepressants, but instead believes she suffered an extreme adverse reaction.

"Prozac was meant to be easier to come off, but I started to feel really confused," she said. "I had a sore head. I should have trusted my instinct and said 'this is not right', but I was terrified to come off the drug because of what I'd experienced before.

"Then, after about a month, it felt like something had fried away. There was this boiling feeling on the right-hand side of my brain.

"When that happened it felt like I lost all sense of myself and the outside world. For three years I've just felt totally alone.

"The feeling in my head is just unlivable. It feels like my whole sense of self, that part of the brain, is gone. They say it's just depression, but it feels like a lobotomy. It's horrific."

Laura is no longer on antidepressants. She lives alone, but can no longer work and relies on benefits, and admits to feeling suicidal.

The Herald: Dr Des SpenceDr Des Spence

Dr Des Spence, a Glasgow GP who has been an outspoken critic of the increase in antidepressant prescriptions, says too many patients "find it impossible to stop them".

As a result, Dr Spence and his colleagues at the Barclay Medical Group have a blanket ban on initiating antidepressants on a patient's first presentation and employ their own mental health staff to cut the waiting time for counselling.

"It may sound odd but it's actually quite an effective way of reducing their initial use," said Dr Spence. "People present in crisis, they offload, you can give them directions to other services, lifestyle advice, and then when you see them again they are often much better. So we've found this practice - of not initiating antidepressants at the first consultation - goes a long way to reducing their use."

Professor Wendy Burn, President of the Royal College of Psychiatrists, said it was vital that funding for mental health research is increased. It currently receives just 6% of total UK health research spending. 

She added:  “Antidepressants are an effective, evidence-based treatment for moderate to severe depression, and are a life-saver for many people.

"But not enough research has been done into what happens when you stop taking them. As this review shows, for many people the withdrawal effects can be severe, particularly when antidepressants are stopped abruptly.

“It’s good to see more of a focus on this. We are pleased that Public Health England are prioritising dependence on, and withdrawal from, prescribed medicines as an area of review."