The government has insisted there is a low rate of mental illness in the armed forces, after a study found that service in Iraq and Afghanistan could result in psychological problems. 

A report published in the British Medical Journal on Friday found that troops based abroad for 13 months or more, were 20 per cent to 50 per cent more likely to display symptoms of post-traumatic stress disorder (PTSD).

Researchers from King's College London, who assessed over 5,500 regular members of army personnel, also found that troops on prolonged deployments were more likely to suffer severe alcohol problems.

Some 10 per cent of respondents said deployments had lasted longer than expected, and the report said people were more likely to suffer from PTSD if their expectations of how long they would be away did not match up with the reality.

However, the Ministry of Defence (MoD) said mental distress was not necessarily associated with "operational deployment" and pointed to figures showing that new cases of PTSD in the armed forces stood at 0.03 per cent in the first quarter of the year.

Defence minister Derek Twigg said the government recognised mental illness "as a serious and disabling condition and we want to ensure that our people have the best possible mental health support".

He pointed to research commissioned by the MoD to monitor the health of UK troops and said the government had "taken great steps to raise awareness and to reduce the stigma associated with mental illness".

Care

Twigg said there were mental health nurses based in Iraq and Afghanistan and out-patient care was easily accessible for troops, once they return home.

"The vast majority of British troops do not have their tours extended and are on operations for no longer than six to seven months," he added. "As such, it indicates that our current policies on the duration of tours are right."

On the high level of alcohol problems among military personnel, he said measures were in place to educate people about the dangers of alcohol abuse with appropriate rehabilitation offered, where needed.

According to the MoD, less than one per cent of the Royal Navy, 12 per cent of Army and six per cent of the RAF are exceeding "harmony guidelines", which were put in place to clarify how much time personnel should spend away from their family and how long rest periods should be.

However Opposition parties claimed the report highlighted how UK troops were overstretched.

Shadow defence secretary Liam Fox said: "Ministers are having our armed forces do too much with too little producing the inevitable consequences for personnel and their families. 

"The government's failure to share the burden of operations with our allies is adding to the pressures. Harmony guidelines that are meant to allow troops to rest and recuperate are habitually breached leaving our troops feeling used and abused by the government. 

"Military psychiatry has been run-down by Labour and farmed out to private contractors. Unsurprisingly big gaps have opened up, particularly in relation to the TA and veterans who may become unwell as a result of their service years after leaving the forces."

And Liberal Democrat defence spokesman Nick Harvey argued that: "This report is yet more evidence of the continuing damage that prolonged army overstretch is having on our soldiers.

"Our armed forces are suffering the consequences of massive overseas commitments, caused in no small part, by the illegal war in Iraq.

"There is one move open to the government that would quickly help to relieve some of this burden and that is to set a framework for a phased withdrawal from Iraq."