A leading London Priory psychiatrist has spoken of a rise in patients suffering Post-traumatic stress disorder (PTSD) after being treated for Covid-19, some of whom were having severe flashbacks of their experience of treatment long after they had physically recovered.

Consultant psychiatrist Dr Paul McLaren, an expert in the treatment of PTSD, said he had treated patients who had suffered “horrific and sometimes bizarre visions” during treatment in intensive care units including seeing medical staff as ghosts or devils.

“I have seen a few patients, with PTSD following hospital treatment for COVID,” he said, “and I would expect there to be a follow-through with others – people who have been on intensive care units who have suffered delirium, an acute confusional state, which can be severe and distressing with disorientation, hallucinations and fragmentary delusions.

“It can be really distressing. They have intrusive memories of their experiences of the delirium and the traumatic things they have seen in that state.

“This manifests itself in nightmares and flashbacks, in which they get memories of their hallucinations which can be very upsetting.”

Dr McLaren is medical director of the Priory’s Hayes Grove Hospital in Kent, and also works at the Priory’s Wellbeing Centres in London, including in Fenchurch Street and Harley Street. He is a member of the International Society for Traumatic Stress Studies. The Priory is best known for its mental health hospital in Roehampton, south-west London, but is the largest independent mental health provider in the UK, with hospitals and clinics across the country.

He said hallucinations were a “recognisable complication of intensive care” adding: “The additional stressors now are everyone wearing PPE and an atmosphere of fear. This may have racheted up the rates of PTSD.”

The consultant said he had treated a patient for PTSD who had spent a month on a ventilator.

ICU staff have long been aware of the risk of adverse psychological reactions to ICU treatment. The high-risk times are usually when patients are waking up in preparation for coming off ventilation, or prior to discharge from an ICU.

So-called ‘long Covid’ was different to PTSD, Dr McLaren said. “We are only starting to learn what ‘long Covid’ is, and its psychological manifestations. It probably has elements of the chronic fatigue you might get after mumps or glandular fever. That can go on for months because Covid is a serious viral infection.

“Hallucinations are caused by an acute confusional state in that brain function gets disrupted very rapidly. That can be caused by a high temperature, dehydration or even sleep deprivation or immune response attacking the brain. With delirium you get disorientated, confused about where you are and visual hallucinations of varying complexity and a sense of intense which can be deeply traumatising.”

The NHS defines PTSD as a condition which can “develop after a very stressful, frightening or distressing event, or after a prolonged traumatic experience”.

It is unclear why some people develop the condition while others do not but some people who have suffered from depression or anxiety in the past, do not have emotional and psychological support or have gone through a traumatic event are more likely to develop PTSD.

The sufferers can experience insomnia, get angry, confused and anxious, have panic attacks, flashbacks or numbness, and feel detached from reality.

Dr McLaren said PTSD was sometimes treated with anti-depressants but the main treatment was psychological – “exposure-based, which means bringing fears to mind while in a state of relaxation”.

He added: “We also know that immediate social support is an important protective factor which of course has been severely disrupted during Covid.

“I have not seen huge numbers with PTSD following Covid but what I have seen makes sense and is what one expects. After major incidents like Covid, PTSD may not come initially because people focus on their physical recovery, breathing, and recovery from long Covid. The psychological effects may be lower down the hierarchy.

“It is quite difficult to predict, but I suspect quite a few people will be traumatised and there will be a definite need for help for PTSD and the complex grief reactions caused by dislocation and separation from loved ones.”

The Royal College of GPs recently said it had reworked its learning materials – initially developed to help GP practices provide targeted support to military veterans returning from war zones and trying to adjust to civilian life – to create specific resources for family doctors helping patients come to terms with the pandemic and its aftermath.

GPs are adapting the techniques they use to diagnose and care for veterans with Post Traumatic Stress Disorder in readiness for a ‘huge surge’ in patients with the condition as a result of COVID-19, they said.

It includes vlogs, screencasts and a PTSD screening test. One section deals specifically with the unique mental health needs of key workers, particularly health and social care professionals who have been on the frontline of the NHS and other public services during the pandemic.

Research has found that in normal times about 40% of people who are discharged after a spell in intensive care develop symptoms of anxiety, 30% have depression and 20% signs of PTSD. The figures for people who have survived an event that involves mass casualties, such as a terrorist attack or transport disaster, are similar.