A major global analysis led by the University of Bath in the UK finds policy reform that removes criminal penalties for cannabis possession, or introduces tightly controlled legalisation, is not associated with increased levels of use. However, legalisation that allows cannabis to be sold for profit is followed by increases in use, addiction and psychiatric hospital admissions.

Women who lift weights may have a lower risk of major heart disease, especially when combined with aerobic exercise, according to a new study published today in JACC, the flagship journal of the American College of Cardiology. Findings show that heart health is better understood by looking at overall movement habits, rather than focusing on single behaviors alone, and resistance training can result in additional health benefits when incorporated into an active lifestyle.

New research shows that climate change could push UK rivers to dangerous extremes and see more frequent rapid swings between wet and dry conditions. Researchers analysed almost 700 river catchments across the UK to project how river flows may change at 2°C and 4°C of global warming. The results reveal stark regional contrasts and growing challenges for communities and water managers trying to plan for flood and drought risk - particularly in areas that will increasingly experience both. The team also warn of more intense river flooding during extreme rainfall events in western and northern parts of the UK and longer dry spells and lower river flows in southern and eastern England, regions that are already water‑stressed.