One in three people seeking medical care for physical ailments might well be suffering from depression, according to Professor Hallman. Headaches, pain, fluctuations in weight as well as a pressing feeling in the chest, stomach problems and a dry mouth can all be symptoms.
Half a million Swedes are thought to suffer from depression in one form or another, and according to the latest figures from the National Institute of public health, some 47% of men and 35% of women are overweight or suffer from obesity.
"Especially in the case of a deep depression many people will first experience it as a physical symptom, also because it is easier to talk about physical rather than psychological problems," said Professor Hallman.
"Children and elderly people in particular lack a vocabulary for expressing psychological distress."
The idea is supported by Elizabeth Goodman, MD, of Brandeis University who, writing in Psychology Today, said, "It's also important to recognize that obesity isn't necessarily caused by overeating. There are different types of depression and different types of obesity. It's easy to say that it's all behavioural. That makes it sound like there's a choice; I'm not sure that it is."
People who receive treatment at an early stage recover more quickly. Sarah Mustillo of Duke University Medical Center says that it is a chicken and egg situation.
"It could be that if you're only obese for six months, there's not as much of an effect as if you were obese for five years. It's probably a combination of social and biological factors. Obesity carries a large social stigma and may bring on depression if it negatively affects self-esteem, body image or social mobility. It may even disrupt the normal hormonal pathways. Then again, depression may also bring on obesity."
It is known that depression causes changes to the brain functions and spark off a complicated chain reaction mimicking stress reactions. The hormones that are activated affect almost every cell in the body.
There is still a great taboo around psychological problems in Sweden, according to Professor Hallman, and so people seek medical help for physical ailments, rather than emotional. She noted that relatives and friends of the depressed person are often better at seeing the emotional caused.
"People should find help as quickly as possible," she said.
"A doctor can distinguish depression from other psychological and physical problems and decide which treatment works best. Depending on the type of depression there is help in the form of medication or psychotherapy."
If you're sure that depression is not the cause of your increasing waistline, and you happen to live in Skövde, then a newly developed corset may be the answer. It pushes back the stomach so that you just can't eat as much as you're used to.
It will be used in a study at the Södra Ryd GP surgery where patients will be strapped into their corsets for nine months. However, only patients who have shown their commitment by losing 8 kilos through ordinary dieting methods can apply.
Lysanne Sizoo is a certified Counsellor, specialising in bereavement, fertility and cultural assimilation issues. She also runs a support and discussion group for English speaking women. You can contact her on email@example.com, or 08 717 3769. More information on www.sizoo.nu.