BY the time Robbie* arrived at Castle Craig in 2015 he was on 15 separate drugs.

He was addicted to gabapentin – prescribed for neuropathic pain – but also had to be weaned off Valium for anxiety and Depakote for bipolar mania. There were anti-psychotics, tramadol and co-codamol - among others.

Robbie, a former professional now aged 50 and living on the outskirts of Edinburgh, credits the Peeblesshire facility for saving his life after a 12 year nightmare which began during an ill-fated holiday in Spain.

He said: “I had a nasty bug, had been violently sick, so I went to the local pharmacy and bought this stuff over the counter called Metoclopramide, an anti-sickness medication.”

Initially, he suffered an allergic reaction known as acute dystonia, characterised by involuntary limb movements, facial grimacing, and distorted speech. Days later, this morphed into a much rarer - and potentially deadly - side effect called Neuroleptic Malignant Syndrome. More than a decade later, Robbie remains scarred by the experience.

He said: "What NMS does is it basically makes your muscles go rigid. All your muscles. It blocks your dopamine receptors and it raises your body temperature and, as I have since discovered, 90 per cent of all the water in your body is in your brain. So effectively, your brain boils. I only remember five minutes, but unfortunately my PTSD seems to remember a lot more. It also gives you neck spasms. Basically I was doing an Exorcist impression."

At the time, however, the condition went undiagnosed and medics mistakenly treated Robbie for dystonia instead. He was given gabapentin, along with trazodone for anxiety and insomnia and amitriptyline for chronic long-term pain.

The trazodone and amitriptyline interacted adversely to trigger Robbie's first bipolar episode. It was the start of a 12-year cycle of pharmaceuticals, mania, psychosis – and pain. At times, his facial muscles clenched Robbie's jaw so tightly that he broke teeth – but he was too tranquilised to notice. On one occasion he stopped lithium too quickly and was awake for six days in a row suffering a bipolar episode that saw him admitted to a psychiatric ward. On another occasion, Pregabalin triggered a bipolar reaction.

He tried to end his life once by overdosing on Tramadol. But a second suicide attempt led him to Castle Craig - where his psychiatrist finally diagnosed NMS. Over six months, Robbie was gradually detoxed off most of his medications. Today, he takes only paracetamol, baclofen - a muscle relaxant - and and prazosin for PTSD.

He said: “The difference in the pain is remarkable. I take paracetamol and baclofen the same way as I took co-codamol and tramadol. I try not to use too much of it. I try to use it when I need it. For years I was poly-pharmacised and misdiagnosed. I owe Castle Craig my life.”

* name changed to protect identity