Incidents of post-traumatic stress disorder have been documented as far back as ancient Greece. The condition has had different labels throughout history.

In the American Civil War, it was called soldier's heart. In the First World War it was called shell shock and in the Second World War it was known as war neurosis. In the Vietnam War, the symptoms were described as combat stress reaction.

Now, more Canadian soldiers than ever are coming forward to make claims for psychiatric disabilities, such as post-traumatic stress disorder (PTSD). The military ombudsman's office in Ottawa made 31 recommendations in a report on PTSD in 2002. In a follow-up report that was released on Dec. 17, 2008, the ombudsman noted that 18 of the 31 recommendations had not been fully implemented.

The report found that the military had made some progress by:

• Improving screening before and after soldiers enter conflict.
• Setting up and funding support groups across the country to help families.
• Committing to hiring 200 more mental health professionals by March 2009.

The report recommended further steps be taken, including:

• Create a full-time operational stress injury co-ordinator responsible for all related issues, including the quality and consistency of care, diagnosis and treatment, as well as training and education.
• Develop a database of Canadian Forces personnel — both regular and reserve forces — affected by stress-related injuries.
• Conduct an independent and confidential mental-health survey of Forces personnel.

The ombudsman has launched a third follow-up investigation on PTSD and hopes to report his findings in the autumn of 2011. According to Darren Gibb of the military ombudsman's office, some important concerns are that a national database is still not in place; and more needs to be done to meet the needs for families of soldiers who have PTSD. On the other hand, Gibb told CBC News that the Canadian Forces are world leaders in the recognition of PTSD and its cultural acceptance.

But the condition doesn't just affect soldiers. Paramedics, police officers, front-line nurses and victims of abuse, violent crimes or accidents have been known to develop symptoms. One in 10 people have post-traumatic stress disorder, according to the Canadian Mental Health Association. Often with time and support, people can get past a traumatic event.

But some people experience such severe psychological stress that it affects them long after. They have flashbacks and nightmares or tune out for periods of time, making it hard to live a normal life. If these symptoms persist for more than a month, it could be post-traumatic stress disorder.

What is post-traumatic stress disorder? What causes it?

Post-traumatic stress disorder, or PTSD, is one of several anxiety disorders, conditions where people feel intense, prolonged feelings of fright and distress for no clear reason. As the name suggests, PTSD is caused by a traumatic event involving threatened death or serious injury to oneself, or from witnessing such events. Stressors such as seeing someone else threatened with death or serious injury, or killed, can also cause it.

Some examples of stressors known to cause PTSD include:

• Violent personal assaults, such as rape or mugging.
• Car or plane accidents.
• Military combat.
• Living in or reporting from a war zone.
• Industrial accidents.
• Natural disasters, such as hurricanes or tornadoes.

A second key factor in PTSD — according to the American Psychiatric Association — is that you have to respond to the stressful incident(s) with intense fear, helplessness or horror.

Emergency workers, like police officers, are trained to control situations that can be severely stressful for most people — not to respond with fear, helplessness and horror. For them, the symptoms of PTSD can set in well after the actual incident(s) took place.

What are the symptoms?

Symptoms usually start to appear three months after the traumatic event. But they can also appear many years later.

They fall into three categories:

Reliving the traumatic event: This is the disorder's main characteristic. Most often, the person has powerful, recurrent memories of the stressor. It can happen in the form of flashbacks or nightmares. Reminders of the event, such as certain images, sounds and smells, often trigger these. They may become distressed, sweat excessively, and their heart rate increases.

Emotional numbing and avoidance: The person may withdraw from friends and family. They avoid situations that remind them of their trauma. They don't enjoy life as usual, and have a hard time feeling emotions or maintaining intimacy. They often feel extreme guilt. In rare cases, they can go through disassociative states where they believe they are reliving the episode, and act as if it is happening again. These can last anywhere from five minutes to several days.

Changes in sleeping patterns and alertness: Insomnia is common, and people with PTSD may have a hard time concentrating and finishing tasks. This can also lead to more aggression.

PTSD can also lead to other illnesses, such as depression or dependence on drugs or alcohol. Some physical symptoms, such as dizziness, chest pain, gastrointestinal and immune-system problems can also be linked to the disorder.

How is PTSD treated?

The depression and anxiety can be treated with medication. Therapy with mental health professionals can help, such as:

• Group therapy.
• Exposure therapy, in which the person works through the trauma by reliving the experience under controlled conditions.
• Cognitive-behavioural therapy, which focuses on the way a person interprets and reacts to experience.
• Some people fully recover within six months, but it can take much longer. Cognitive-behavioural therapy appears to be the most effective treatment, according to research.
• Virtual reality therapy, only available in the U.S. Patients' traumatic memories are recreated with computers, then they are walked through the scene repeatedly, lessening the panic.

David Nobilese yawns and rubs his face at the beginning of a post deployment health reassessment at the Pennsylvania Army National Guard Armoury in 2007. (Carolyn Kaster/AP Photo)But PTSD research continues to determine which treatments work best.

In April 2008, Dr. Florin Dolcos, a professor of psychiatry and neuroscience at the University of Alberta, presented his research that shed a light on differences in the brains of soldiers with PTSD compared to soldiers who return from combat without the condition.

Scans of 42 U.S. soldiers who had served in Iraq or Afghanistan showed differences in areas of brain activity when they performed a series of short-term memory tasks that tested their focus.

The functional magnetic resonance imaging scans showed differences in areas of the brain affected by PTSD, including those involved in helping people stay focused and govern the sense of self.

Dolcos proposed that the research could eventually lead to the use of brain scans to diagnose PTSD, tailor treatment or even identify people who might be at risk of developing the condition if they're exposed to violence in a war zone.

How many people does it affect? Who does it affect?

About one in 10 people have PTSD, according to the Canadian Mental Health Association. It can affect anyone who has a traumatic experience. Children and adults alike can suffer PTSD, which is among the most common mental health problems.

But, some people can experience symptoms without developing PTSD. About five to 10 per cent of people may have some symptoms without developing the full-blown disorder, according to the B.C. Ministry of Health Guide. Women are twice as likely as men to develop the full-blown disorder.

In 2002, the Canadian Forces was surveyed by Statistics Canada to determine the prevalence of PTSD and other conditions. The survey found that in the year before the study, 2.8 per cent of the regular force and 1.2 per cent of the reservists had symptoms of PTSD. The more missions soldiers had embarked on, the more likely they were to develop the disorder or PTSD-like symptoms.

In 2009, the Canadian Forces Surgeon General, Hilary Jaeger, gave a House of Commons committee the results from questionnaires completed by 8,200 soldiers returning from duty in Afghanistan. According to the committee's report, she said 4 per cent responded "in a manner consistent with PTSD." Those findings also confirm that risk "increases with the number of individual deployments to stressful missions."

But, the rate might be much higher, says Dr. Greg Passey, a Vancouver psychiatrist who specializes in trauma and works with Canadian Forces patients. In the mid-1990s, Passey studied two battalions who had served in the former Yugoslavia and found a 12- to 13- per-cent rate of PTSD.

Because our military is so small, he told CBC News, the front-end combat people have to go on more than one tour. And, he added, the more traumatic situations a person is exposed to, the greater risk of developing an operational stress injury such as PTSD.

The Canadian Forces now screens soldiers three to six months after they return from a mission. The "enhanced post-deployment screening process" involves a set of standard health questionnaires and an in-depth interview with a mental health professional.

If I have symptoms of post-traumatic stress disorder, what can I do to cope?

Veterans Canada recommends a few common sense tips.

• Live a healthy lifestyle, eating healthy meals, exercising regularly and getting enough rest.
• Set aside time to reflect on the trauma, rather than allow a constant stream of worrying thoughts throughout the day.
• Join or develop support groups.

Educate yourself and your family about reactions to trauma. Understanding the condition is helpful in coming to terms with the trauma and dealing with its associated problems.

If you are a soldier with an operational stress injury like PTSD or think you may be, or if you are a family member of one, you may contact the Canadian Forces' Operational Stress Injury Social Support network (OSISS) online or at 1-800-883-6094.