Most psychiatric diagnoses are purely descriptive. For example, a diagnosis of depression is only a description of the various psychological symptoms — not the cause. Yet depression is often talked about as a disorder that causes low mood and other symptoms.

Researchers describe this as a form of circular reasoning, which means that psychiatric diagnoses are frequently talked about circularly, as if they described the causes for symptoms. This makes it difficult for people to understand their distress.

“Depression should be considered as a diagnosis similar to a headache. Both are medical diagnoses, but neither explains what causes the symptoms. Like a headache, depression is a description of a problem that can have many different causes. A diagnosis of depression does not explain the cause of depressed mood any more than a diagnosis of headaches explains the cause of pain in the head,” says Jani Kajanoja, a postdoctoral researcher and a medical doctor specialising in psychiatry at the University of Turku in Finland.

This misconception is also perpetuated by mental health professionals, shows a recent study by the University of Turku and the University of the Arts Helsinki.

In the study, the researchers analysed publicly available information on depression provided by leading international health organisations. The researchers selected the websites of English-language organisations whose information on depression was the most influential according to search engine results. The organisations included the World Health Organisation (WHO), the American Psychiatric Association (APA), National Health Service (NHS) in the UK, and Harvard and Johns Hopkins Universities, among others.

Most organisations portrayed depression on their website as a disorder that causes symptoms and/or explains what causes the symptoms, although this is not the case. None of the organisations presented the diagnosis as a pure description of symptoms, as would have been accurate.

“Presenting depression as a uniform disorder that causes depressive symptoms is circular reasoning that blurs our understanding of the nature of mental health problems and makes it harder for people to understand their distress,” says Kajanoja.

The researchers suggest that the problem may be caused by a cognitive bias.

“People seem to have a tendency to think that a diagnosis is an explanation even when it is not. It is important for professionals not to reinforce this misconception with their communication, and instead help people to understand their condition,” says Professor and Neuropsychologist Jussi Valtonen from the University of the Arts Helsinki.