UK doctors subject to complaints procedures are at significant risk of becoming severely depressed and suicidal, reveals research published in the online journal BMJ Open.

Those referred to the UK professional regulator, the General Medical Council, seem to be most at risk of mental ill health, the findings suggest.

The researchers base their findings on an anonymised online survey of more than 95,000 UK doctors in 2012, all of whom were members of the British Medical Association (BMA).

Almost 8000 (8.3%) fully completed the questionnaire and were included in the final analysis. Respondents were broadly representative of the BMA membership in terms of gender mix and place of qualification, although there were some differences in ethnic background and age range.

Respondents were streamed into three groups: those subject to a current/ongoing complaint within the past 6 months (recent); those who had endured a complaint more than 6 months ago (past); and those who had no personal experience of a complaint.

The survey questions were designed to probe attitudes to any type of complaints procedure, ranging from informal through to referral to the GMC, as well as the psychological and professional fall-out of going through the process, and what might be done to improve it.

The survey also included questions about medical history; validated tests of depression and anxiety; and an assessment of life satisfaction.

Around one in five respondents (22.5%) had no personal experience of a complaint; almost half (49%) had faced a complaint in the past; and more than one in four (28.5%) had done so recently.

Around one in six (just under 17%) of those with a recent complaint were moderately to severely depressed, and they were 77% more likely to report these symptoms than doctors in the other two groups, after taking account of influential factors.

And they were twice as likely as those who had no personal experience of a complaint to harbour thoughts of self-harm or suicide.

A similar proportion (15%) of those in the recent/ongoing complaints category were also twice as likely to have clinically significant levels of anxiety as doctors with no personal experience of a complaint.

Levels of psychological distress paralleled the type of complaint. Doctors who had been referred to the GMC reported the highest levels of depression (more than 26%), anxiety (more than 22%), and thoughts of self-harm (more than 15%).

Doctors subject to a recent/ongoing complaint were also more likely to have poorer health and wellbeing, including gut problems, insomnia, and relationship issues.

Defensive practice was common, with most (80%) of those who had experienced a complaint saying they had changed their clinical practice as a direct result, deploying tactics such as avoidance--not carrying out difficult surgery, for example--or hedging--ordering too many investigations, for example--and in some cases, acting against their professional judgement.

Furthermore, almost three out of four of those who had not been the subject of a complaint said they had also changed their clinical practice after witnessing a colleague's experience of going through the process.

"These behaviours are not in the interest of patients and may cause harm, while they may also potentially increase the cost of healthcare provision," note the researchers.

The process itself was often an unpleasant experience for the doctors involved. One in five of those who had been subject to a complaint felt victimised for having blown the whistle on poor clinical or managerial practice, and almost four out of 10 (38%) said they felt bullied during the investigation. And around one in four had taken more than a month off work.

Most of the respondents who offered suggestions for ways to improve complaints procedures focused on boosting managerial competence in complaints handling; greater transparency; and disciplinary action for vexatious complaints.

The researchers caution that the overall response rate may mean that these findings are not truly representative of doctors working in the UK, and this is an observational study so no definitive conclusions about cause and effect can be drawn.But as the largest UK study of its kind, they believe the findings are relevant.

They emphasise the importance of protecting patient safety and of enabling complaints to be raised as a way of improving standards of care, but go on to say: "However, a system that is associated with high levels of psychological morbidity among those going through it is not appropriate. Most importantly, a system that leads to so many doctors practising defensive medicine is not good for patients."