The NHS in England is not doing enough to help people with mental health conditions quit smoking, an influential group of doctors has warned.
People with mental health disorders, such as depression, are twice as likely to smoke and tend to be more addicted.
Yet the NHS is turning a blind eye and not doing enough to help them to stop, the Royal College of Physicians said.
The Department of Health said it was committed to tackling the issue in the future.
The report, which was also put together by the Royal College of Psychiatrists, points out that although rates of smoking in the general population have fallen substantially over the past 20 years, there has been little change in people with mental health conditions.
A third of all cigarettes in England are smoked by someone with a mental health disorder, the report said.
Yet they are just as likely to want to quit as anyone else but are likely to be more addicted and lack the right support to stop, the report found.
Smoking has become engrained into the culture in many institutions caring for people with mental health problems and making them totally smoke-free environments should be a priority, it concluded.
And although the usual smoking cessation treatments such as nicotine replacement therapy is effective, people with mental health conditions may need higher doses or more intensive support, it said.High cost
It is estimated that the NHS spends around £720m a year treating smoking-related illness in people with mental health disorders - mostly on people with depression or anxiety.
The failure of smoking prevention and treatment in this group is largely down to an acceptance of smoking as a "normal behaviour" and is an indictment on public health and clinical services, it said.
The report added that there "was no justification for healthcare staff to facilitate smoking".
Prof John Britton, director of the UK Centre for Tobacco Control Studies at the University of Nottingham and report chairman, said people with mental health disorders might find it harder to quit smoking but that did not mean they did not want to stop.
He added in some mental health services there was a culture in which smoking was acceptable.
"The patients are seen as having a hard time and are ill so they need a cigarette and it is also a way for staff to build relationships and so they end up facilitating smoking breaks, finding time to supervise people who want to go outside to smoke, rather than spending resources on helping them to stop."
He added that although people with depression and anxiety might start smoking because they find it helps, it soon starts to exacerbate their problems.
"If they stop smoking, a year down the line, they will feel substantially better," he added.
Paul Farmer, chief executive at the mental health charity Mind, said: "This report highlights once again that the needs of people with mental health problems are often overlooked or ignored."
A Department of Health spokesman said: "This is an important issue, and frankly, a difficult one. We are aware that more work needs to be done to tackle it fully."
He said in the future the government was looking to focus efforts on reducing smoking among vulnerable groups, such as mental health patients.