Talking therapy is helping cancer patients cope with the "Damocles effect" - the fear that their disease might cut them down at any moment.
Cancer sufferers are often plagued with acute levels of anxiety and distress even when their illness is stable, or in remission. It is estimated that between a quarter and a third of them have serious mental problems, such as clinical depression.
For many, the threat of the disease returning, taking a turn for the worse, making them disabled or ending their lives is a constant fear.
At St James's Hospital, Dublin, psychologists are using new forms of Cognitive Behaviour Therapy (CBT) to help cancer patients cope with the threat.
Patients are taught to accept the uncertainty of life with cancer, and to stop dwelling on the past or future.
The programme has been highly successful, according to Dr Sonya Collier, the clinical psychologists who introduced it to the hospital in 2003.
"We focus on not trying to pretend to people that their thoughts are irrational, but to look at how they can adjust their ways of thinking to obtain the best quality of life. Acceptance plays a big role - it's about learning to live with uncertainty," she said.