So you don't like Mondays? It's all in your mind

The grumpy mood and inability to get out of bed that characterises many people's Monday mornings may be all in the mind, according to a new study.

Research to be discussed at the annual meeting of the Royal College of Psychiatrists, which begins today, found that people who believe that they will suffer from the "Monday Blues" are more likely to experience them.

Giles Croft, a 24-year-old medical student who designed and carried out the study, set up three sample groups of 22 people. One group received a copy of a "report" entitled: "Monday Blues - The Myth", which refuted the existence of Monday-related depression and, using graphs, emphasised that it was no different to any other weekday.

The second received a report entitled "Monday Blues - Here to stay", emphasising the bad moods associated with Mondays and illustrated with a graph "proving" this. The third group received nothing at all.

All participants also wrote a "daily mood diary" for two weeks, in which they wrote measures of how they had felt and ranked days of the week retrospectively in terms of feelings.

"We used the "Monday blues" because they're not a recognised phenomenon. We used them because I thought I would be able to manipulate people into thinking they did or didn't exist," Mr Croft said.

The results showed that on Mondays the "anti-blues" group reported significantly more positive feelings (enthusiastic, inspired and strong) than the "pro- blues" group. When average scores for each day were ranked, the "pro-blues" group rated Monday as the worst day of the week, while the "anti-blues" did not.

"The manipulation appears to have worked for concurrent reports yet when asked to recall how they felt over two weeks afterwards each group came back saying Monday was the worst. They persuaded themselves with hindsight."

Mr Croft concluded that direct manipulation of expectations can affect mood. This, they say, could have implications for the way people see themselves in clinical situations, for example, their expectations of illness. It also shows, they say, the "relative unreliability" of restrospective self- reports of mood.