Years of war and bloodshed have left many Iraqis suffering from mental disorders but stigmas attached to such illnesses prevent most from seeking treatment, a survey published said.

Sponsored by Iraq's ministry of health and the World Health Organisation (WHO), the survey found that 16.5 percent of Iraqis have suffered from a mental problem but just 2.2 percent had sought help.

"In Iraq there is considerable stigma attached to having a mental illness," said Health Minister Saleh Mahdi al-Hasnawi.

"We must implement large-scale community education programmes to decrease this stigma and encourage people to come forward and seek the treatment they need."

The report covers 4,332 adults aged 18 years and older from Iraqi households throughout the country.

It said anxiety disorders were the most common class of disorder and depression the most common mental health problem. Disorders that were most often classified as severe were bipolar disorder and substance-abuse.

However, resistance to the mental effects of violence was also high among adults in Iraq, according to the study.

It found that the prevalence of post-traumatic stress disorder was 3.6 percent, lower than expected after six years of conflict and violence in the wake of the 2003 US-led invasion.

Researched in 2006-2007 at the height of a bloody sectarian conflict that left tens of thousands dead, the report said that Iraqis had developed innate mechanisms to handle their stressful environment.

"Stress levels are high while mental disorders are comparable to other countries," said Naeema al-Gasseer, WHO's representative in Iraq.