People can die simply because they've given up, life has beaten them and they feel defeat is inescapable, according to new research.
The study, by Dr John Leach, a senior research fellow at the University of Portsmouth, is the first to describe the clinical markers for 'give-up-itis', a term used to describe what is known medically as psychogenic death.
It usually follows a trauma from which a person thinks there is no escape, making death seem like the only rational outcome.
If not arrested, death usually occurs three weeks after the first stage of withdrawal.
Dr Leach said: "Psychogenic death is real. It isn't suicide, it isn't linked to depression, but the act of giving up on life and dying usually within days, is a very real condition often linked to severe trauma."
He describes in clinical detail the five stages leading to progressive psychological decline and suggests give-up-itis could stem from a change in a frontal-subcortical circuit of the brain governing how a person maintains goal-directed behaviour.
The likely candidate in the brain is the anterior cingulate circuit, responsible for motivation and initiating goal-directed behaviours.
He said: "Severe trauma might trigger some people's anterior cingulate circuit to malfunction. Motivation is essential for coping with life and if that fails, apathy is almost inevitable."
Death isn't inevitable in someone suffering from give-up-itis and can be reversed by different things at each stage. The most common interventions are physical activity and/or a person being able to see a situation is at least partially within their control, both of which trigger the release of the feel-good chemical dopamine.
"Reversing the give-up-itis slide towards death tends to come when a survivor finds or recovers a sense of choice, of having some control, and tends to be accompanied by that person licking their wounds and taking a renewed interest in life," he said.
The five stages of give-up-itis are:
1. Social withdrawal - usually after a psychological trauma. People in this stage can show a marked withdrawal, lack of emotion, listlessness and indifference and become self-absorbed.
Prisoners of war have often been described in this initial state, having withdrawn from life, of vegetating or becoming passive.
Dr Leach said withdrawal can be a way of coping, to pull back from any outward emotional engagement to allow an internal re-alignment of emotional stability, for example, but if left unchecked it can progress to apathy and extreme withdrawal.
2. Apathy - an emotional or symbolic 'death', profound apathy has been seen in prisoners of war and in survivors of shipwreck and aircraft crashes. It's a demoralising melancholy different to anger, sadness or frustration. It has also been described as someone no longer striving for self-preservation. People in this stage are often dishevelled, their instinct for cleanliness gone.
Dr Leach said one prisoner of war who was also a medical officer described being in this stage as waking each morning but being unable to summon the energy to do anything. Others describe it as a severe melancholy, where even the smallest task feels like the mightiest effort.
3. Aboulia - a severe lack of motivation coupled with a dampened emotional response, a lack of initiative and an inability to make decisions.
People at this stage are unlikely to speak, frequently give up washing or eating and withdraw further and deeper into themselves.
At this stage, a person has lost intrinsic motivation - the ability or desire to start acting to help themselves - but they can still be motivated by others, through persuasive nurturing, reasoning, antagonism and even physical assault. Once external motivators are removed, the person reverts to inertia.
Dr Leach said: "An interesting thing about aboulia is there appears to be an empty mind or a consciousness devoid of content. People at this stage who have recovered describe it as having a mind like mush, or of having no thought whatsoever. In aboulia, the mind is on stand-by and a person has lost the drive for goal directed behaviour."
4. Psychic akinesia - a further drop in motivation. The person is conscious but in a state of profound apathy and unaware of or insensitive to even extreme pain, not even flinching if they are hit, and they are often incontinent and continue to lie in their own waste.
A lack of pain response is described in a case study in which a young woman, later diagnosed with psychic akinesia, suffered second-degree burns while visiting the beach, because she hadn't removed herself from the sun's heat.
5. Psychogenic death - Dr Leach describes this final stage as the disintegration of a person.
He said: "It's when someone then gives up. They might be lying in their own excreta and nothing - no warning, no beating, no pleading can make them want to live."
In concentration camps, people who reached this stage were often known to be near death by fellow prisoners when they took out a hidden cigarette and began smoking it. Cigarettes were highly valuable in the camps and could be traded for important things such as food.
Dr Leach said: "When a prisoner took out a cigarette and lit it, their campmates knew the person had truly given up, had lost faith in their ability to carry on and would soon be dead."
The progress from stage four, psychic akinesia, to stage five, psychogenic death, generally takes three to four days and shortly before death, there's often a false dawn - a flicker of life, for example, when someone suddenly enjoys a cigarette.
Dr Leach said: "It appears briefly as if the 'empty mind' stage has passed and has been replaced by what could be described as goal-directed behaviour. But the paradox is that while a flicker of goal-directed behaviour often takes place, the goal itself appears to have become relinquishing life."