London: Living a sedentary lifestyle could increase your risk of developing psychosis leading to early death, a study has warned. Physical inactivity is the fourth leading cause of avoidable death and is as harmful as smoking, according to World Health Organisation (WHO). The researchers found that people with psychosis -- a mental disorder characterised by a disconnection from reality -- die up to 15 years before the general population, largely due to heart diseases. Adults aged 18-64 must indulge in at least 150 minutes of moderate-intensity physical activity throughout the week, including walking, cycling, household chores or sport, according to recommendations by WHO. The research also offers important insights into the barriers that prevent people with psychosis from engaging in regular physical activity. Mobility difficulties, pain, depression and cognitive impairment explained low levels of physical activity in people with psychosis, the researchers said. "Understanding and overcoming these barriers could be an important strategy to help people with psychosis be more active, and potentially reduce their risk of cardiovascular disease,” said Brendon Stubbs from King's College London. For the study, the researchers analysed more than 2,00,000 people aged 18-64 from nearly 50 low-and-middle-income countries to examine whether people with psychosis are meeting the WHO's recommended levels of physical activity. These individuals were divided into three groups: people with psychosis, those with psychotic symptoms but no diagnosis and a control group (of people with no diagnosis of psychosis and no symptoms in the past 12 months). Overall, people with psychosis were 36 per cent more likely not to meet the recommended physical activity levels compared to control ones. When the researchers looked at men only, those with psychosis were over twice more likely not to meet the recommended levels compared to people in the control sample. "It is unclear why men with psychosis showed such low levels of physical activity, although perhaps the earlier onset of illness typically seen in males means that lifestyle habits may have been altered over time by aspects of the illness or its management, such as negative symptoms, sedating medications or hospital admissions," explained Fiona Gaughran, from King's College London. The study, published in Schizophrenia Bulletin, will help interventions aimed at helping people with psychosis to be more active and ultimately improve their mental and physical condition.