ANTIDEPRESSANTS have been linked to more fatal overdoses in Scotland than methadone for the third year in a row, amid a surge in drug deaths among people treated for depression and anxiety.

Although rarely the cause of death, antidepressants are increasingly being found in post-mortems of individuals who have suffered an accidental drug death, according to a report by ISD Scotland.

In 2016, they were mentioned in 47 per cent of post-mortems - up from 21 per cent in 2009. 

Read more: Experts 'in denial' over prescription pill harm

After heroin, morphine and alcohol, antidepressants were more likely to be detected than any other substance, including methadone, which was found in 373 post-mortems compared to 385 for antidepressants.

HeraldScotland:

In around a third of cases, the antidepressants had not been prescribed  "[suggesting] that illicit use of these substances may be increasing or that their use may be a potential risk factor for drug-related death".

Heroin, morphine, methadone and buprenorphine - better known by the brand name Subutex - were still the leading causes of death, however. Pathologists blamed them for 618 of the 865 accidental drug deaths in Scotland in 2016.

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In the vast majority of fatal overdoses multiple substances were detected, however. Addicts often mix illicit and prescription drugs to enhance their high, but doing so significantly increases toxicity and risk of death.

In cases where people ended their lives intentionally by overdose - which are counted separately in the statistics - antidepressants were the most common cause of death, cited in 20 out of 47 suicides.

Read more: Revealed - Scotland's heroin death hotspots

Dr Ahmed Khan, a consultant in addiction psychiatry and chair of the Faculty of Addictions Psychiatry at the Royal College of Psychiatrists Scotland, said it partly reflected increased intervention.

He said: "When people abuse opiates their chances of having a depressive illness are very much higher - some people cite up to six times higher.

"More and more people with drug-related problems are now in contact with mental health services than ever before, and more and more people are subsequently being diagnosed with mental illnesses."

HeraldScotland:

It comes as figures also reveal that the number of drug deaths involving people recently treated for depression and anxiety have soared almost four-fold since 2009.

In 2009, 98 people who died following an accidental overdose were recorded as having depression.

By 2016, this had risen to 387. Among patients suffering from anxiety, non-intentional drug deaths have risen from 66 to 255 over the same period.

Read more: Prescription drugs gabapentin and pregabalin cited in quarter of fat overdose post-mortems

In contrast, drugs deaths among people treated for other psychiatric illnesses - such as post-traumatic stress disorder, schizophrenia or bipolar disorder - have remained largely static.

Meanwhile, drug deaths among patients treated for chronic pain have increased faster than for any other physical condition, from fewer than one per cent in 2009 to 11 per cent in 2016 - or 90 cases.

Fatal overdoses, including opioid-related drug deaths, hit a record high in Scotland in 2016. Scotland's drug-related death rate - at 16 per 100,000 - is higher than anywhere else in the UK or Europe, and increasing.

In the US, where the death rate from drug overdoses is running at 19.8 per 100,000, a national public health emergency has been declared in relation to opioids and the report added that Scotland's "proximity to these high rates is noteworthy".

Dr Khan added that Scotland had a long-standing issue with substance abuse.

He said: "Even in the 1930s, barbiturate deaths in Scotland were the highest in the world.

"This situation with heroin is only 30-40 years old, it's still relatively new. Even our alcohol problems remain terrible."