Most of us can find some joy in Christmas — even this year — but just imagine what it would be like if you couldn’t, or, indeed, if you took no pleasure in anything most people enjoy, from eating a lovely dinner to going for a walk.
This is how some people feel every day, owing to a condition called anhedonia.
‘It is likely to get worse at Christmas, too, because there is an expectation at this time of year that everybody must be happy,’ says Carmine Pariante, a professor of biological psychiatry at King’s College London.
Social anhedonia involves not wanting to spend time with others because it is not enjoyable. It is distinct from social anxiety, which is driven by a fear of social situations [File photo]
‘So people who are not feeling happy may think that they are failing, and that there is something profoundly wrong with them, rather than just seeing it as a manifestation of a disorder that is not their fault.’
Medically defined as an inability to find pleasure in normally pleasurable experiences, there are two forms: social and physical. Most of those with the condition have both.
Social anhedonia involves not wanting to spend time with others because it is not enjoyable. It is distinct from social anxiety, which is driven by a fear of social situations.
And while we may all prefer our own company occasionally, for people with the condition the feeling doesn’t vary.
Those with physical anhedonia experience a lack of enjoyment from sensations, such as being hugged, eating chocolate, having sex or listening to music — as many as 3 per cent of adults are said to have musical anhedonia.
Medically defined as an inability to find pleasure in normally pleasurable experiences, there are two forms: social and physical. Most of those with the condition have both [File photo]
‘People with anhedonia cannot anticipate the pleasure they could get from certain activities or sensations, so they cannot motivate themselves to seek them out,’ says Professor Pariante. ‘Even if they do, they won’t feel any pleasure.’
The condition can be diagnosed with a 14-question test that rates how much pleasure people get from everyday events. People who do not enjoy three or more of these are diagnosed with anhedonia.
Despite having been recognised as a problem for more than a century, its cause is still not fully understood, although recent research has focused on the reward system in the brain.
This regulates behaviour by inducing pleasurable effects. When we do certain things, such as eating or watching a film, the brain rewards us by releasing chemical messengers to make us feel good.
This may explain why women are more likely to have anhedonia, as, according to a University of California study last year, women’s brains are less sensitive to these chemicals than men’s if both are affected by inflammation.
The feel-good chemical dopamine is believed to be a key player. Areas of the brain thought to control the release of the chemical have been shown to be less active in people with anhedonia.
‘In fact, all aspects of the reward process are impaired for them,’ says Professor Pariante. ‘When you measure the activity of the areas involved in the reward process using functional magnetic resonance imaging, you find they do not light up as they do in healthy people.’
It’s estimated that up to one in five people with chronic pain, including arthritis, may suffer with anhedonia, but it can also affect people who are otherwise healthy.
A 2017 study in the Journal of the Neurological Sciences, which was looking at anhedonia in Parkinson’s disease, found that around 4 per cent of the healthy control group — albeit only three people — met the criteria for anhedonia.
And, according to a study earlier this year, published in Frontiers in Psychiatry, around 75 per cent of those with depression have it.
When it comes to anhedonia’s link to other diseases, dopamine again seems to be the key; stress caused by chronic pain is thought to interfere with the reward system via reduced dopamine.
Several new treatments are emerging. Doctors at Lund University in Sweden are trialling pramipexole, a drug used to treat Parkinson’s, for anhedonia patients. It works by increasing levels of dopamine. Results are expected shortly.
Meanwhile, research from Johns Hopkins University School of Medicine in the U.S. has revealed that this lack of enjoyment can be turned on and off by drugs which alter levels of dopamine.
In the latest study, published in the Journal of Affective Disorders, researchers found that the drug esketamine, used in anaesthesia, can help patients with anhedonia and depression. It, too, increases dopamine levels.
However, it’s a controversial treatment and this year health watchdog NICE rejected its use for depression partly because there is not enough evidence it works.
Other experts believe it’s important to tackle lifestyle factors that may affect dopamine, such as getting enough sleep, exercising and eating healthily. They also recommend cognitive behavioural therapy to challenge thinking.