Psychological trauma has been around far longer, of course. The term shell shock was used to describe soldiers who broke down during the trench warfare of World War One.

PTSD doesn’t just affect soldiers. Police and rescue workers are at risk. So are civilians caught in war zones or natural disasters, as well as victims of sexual assault and car crashes.

Most journalists are resilient despite repeated exposure to work-related traumatic events, according to research on the website of the Dart Center for Journalism and Trauma, a project of the Columbia Journalism School in New York. But a significant minority are at risk of long-term psychological problems, including PTSD, depression and substance abuse, it adds.

I never thought I’d get PTSD. I was calm, rational and decisive. I enjoyed being in charge of large editorial teams. I felt I could detach myself from tough situations when needed.

But occasionally last year I couldn’t get out of bed. I’d sit at my desk in my study trying to work, barely able to lift my head. When I got stressed, I was flung back in time to our office in Baghdad, as if I had never left. I would bang my fists on the desk, scream at the walls.

I was so sensitive to noise that my teenage children would freeze if they dropped something. Mary wouldn’t vacuum if I was in the room. On several occasions last year, after having read about PTSD and spoken to an expert on the condition, she told me I needed help.

But when I gave in and saw a psychologist in mid-2015, he ruled out PTSD, saying I was suffering from an identity crisis because I no longer had a high-profile job and had moved to a quiet country area where no one knew me. I didn’t have PTSD, I insisted to Mary.

Months later my irritability, numbness and simmering anger reached a stage where, with my marriage at breaking point this March, I finally agreed to see the psychiatrist who diagnosed me with PTSD.

BUSHWALKING AND ANTI-DEPRESSANTS

Without hesitation, my editors gave me three months off. I started taking anti-depressants. In the weeks after the diagnosis, I was often fatigued. In early May, I postponed my return to work to July. I did an eight-week mindfulness course through May and June, hoping meditation would help me cope with stress and anxiety.

The best therapy, or so I thought, was bushwalking.

In Tasmania’s rainforest I found what I was looking for – peace. I loved walking trails where I could touch ancient trees, sit by swift rivers or stare at misty mountains. I’d leave my troubled mind behind and just breathe the rainforest. I began devouring books on Tasmania’s wilderness and the history of its wild West Coast.

In line with risk-taking behaviour associated with PTSD, I began planning multi-day hikes alone, in the middle of winter. Worried, my father-in-law, an experienced bushwalker, gave me his pocket-sized personal locator beacon. In the end, I took his advice and stuck to less dangerous hikes.

When I wasn’t bushwalking, I was agitated, anxious and often craving solitude. In early June, when Mary said she and the children were walking on eggshells at home because of my state of mind, I raged at her, pacing around like a caged animal. Mary left the room, thinking I’d hit her if she challenged me.

On June 27, I wrote in my journal: “I’m one brain snap away from a ledakan.” I used the Indonesian word for “explosion,” worried that if Mary saw it in my journal, she’d freak out.

The next day, I sent my editors an email saying I could not resume editing stories because it would be too stressful. My psychiatrist agreed.

In July, I deteriorated. I was severely depressed. I felt like I was living in a mental fog. My nightmares worsened. In the most frightening dreams, I ran through the streets of Baghdad pursued by insurgents. On most nights, Mary said my feet were moving in my sleep, as if I was running. To get to sleep I took paracetamol and codeine tablets. I started drinking heavily. Some days I just stayed in bed.

In the week before the ninth anniversary of the deaths of Namir and Saeed, I began thinking deeply about them and my actions as bureau chief at the time. I scrutinised emails I had kept from that period, asking myself if I did enough to investigate their deaths. In particular, I dwelt on the classified U.S. military video released by WikiLeaks in 2010, three years after the attack, that showed helicopter gunsight footage of them being killed along with around 10 other people.

The attack came on the morning of July 12, 2007. I was sitting in the bureau “slot position” – responsible for writing the lead story of the day and manning the main phone line to regional headquarters in London. All of a sudden, a loud wailing broke out near the entrance to the two-storey house that served as our office. I knew instantly something horrific had happened. I still remember the anguished face of the colleague who burst through the door to break the news. Another colleague translated for me: Namir and Saeed had been killed.

They had gone to east Baghdad after hearing of a U.S. airstrike on a building around dawn that day. As they walked down a street, they found themselves among a half dozen or so people, the WikiLeaks footage later showed, some of whom appeared to be armed. A U.S. Apache helicopter opened fire with 30 mm cannon, apparently mistaking Namir and Saeed for combatants.

Namir was killed in the first wave, the footage showed; Saeed was gunned down in a second attack. The banter between the chopper pilots was shocking. “Oh, yeah, look at those dead bastards,” a pilot is heard saying. “Nice,” a comrade replies.

Outwardly, I kept calm and focused on trying to find out what led to the attack, dealing with the U.S. military and consoling our staff. Compounding the bureau’s grief, an Iraqi translator working for Reuters was shot dead in Baghdad by gunmen the day before Namir and Saeed were killed. We only found out a couple of days later, when he didn’t show up for work. (The translator’s parents asked that we not reveal his name.)

Inside, I was falling apart.

A few days after Namir and Saeed died, I nearly had a nervous breakdown in my office. As I wept, I thought the best thing to do was resign. The stress was too much. Someone stronger needed to take over. But I pressed on.

I was on holiday in Tasmania when the WikiLeaks video was released on April 5, 2010, but I felt cowardly because I had left it to others in Reuters to respond to what was a major global story, even though I felt I knew the situation better than anyone. The video, titled “Collateral Murder,” was viewed millions of times.