London, May 12 (IANS): People suffering from psychosis, a mental health problem that causes people to lose contact with reality, are likely to have high levels of cardiovascular risk factors such as excessive fat around the stomach, says new research.

The two main symptoms of psychosis are hallucinations and delusions where a person believes things that are obviously untrue.

In the largest study of its kind in Britain, drawing on a sample of more than 400 outpatients with psychosis, the researchers found central obesity evident in over 80 percent of participants.

"While previous research has demonstrated that people gain weight on starting anti-psychotics, our study of people who have had psychosis for nearly 16 years on average found no difference in the rates of cardiovascular risk between the various different anti-psychotic medications," said senior author Fiona Gaughran from King's College London.

The researchers found that 48 percent of the study participants were obese, with a body mass index (BMI) of 30 or more.

Additionally, nearly all women and many men had a waist circumference above the International Diabetes Federation's (IDF) threshold for central obesity.

According to this measure 83 percent of patients were centrally obese: 95 percent of females and 74 percent of males. Central obesity refers to excessive fat around the stomach and abdomen, to the extent that it is likely to have a negative impact on health.

The majority of participants tested (57 percent) met the IDF's criteria for metabolic syndrome, which is a cluster of biochemical and physiological abnormalities associated with the development of heart disease, stroke and Type-2 diabetes.

"The worryingly high levels of cardiovascular risk shown in our study indicate that a much greater emphasis on physical activity is needed for those with severe mental illnesses, as well as a more significant focus on supporting attempts to quit smoking," Gaughran noted.

The study was published in the journal Psychological Medicine.