A leader is like the captain of a ship, guiding a team through a sea of uncertainty. Steering the ship is easy when the waters are calm. The acid test of leadership arises when the ship passes through a catastrophic and unprecedented storm.

In July 2011, a car bomb exploded outside Norwegian government buildings in Oslo, killing eight ministerial employees and injuring over two hundred, in a terrorist attack. Many survivors battled severe mental distress. Ten months after the bombing, 1,800 survivors took part in a study to identify the precise workplace factors that protected survivors from mental distress, in the aftermath of the attack.

The study flagged four factors that had both a synergistic and an independent effect on the risk of mental distress:

1. Role Conflict

Role conflict describes what happens when employees feel "pulled in different directions" because different people simultaneously demand different things from them, and it is impossible to satisfy everyone.

Following intense stress, your cognitive resources are working at full capacity. Role conflict puts additional strain on your mental state because you don't have a clear direction to aim for and the emotional strain of conflict contributes to emotional exhaustion.

2. Role Clarity

Intense stress makes you feel you have no control over your life and your environment. You need to offset this by acquiring more control over the things you can control.

A leader who tells you exactly what is expected of you, how you are expected to deliver it and what your identity is within the team, gives you control over your immediate fate.

3. Predictability

A sudden traumatic experience makes your world feel more uncertain. In the midst of uncertainty, you want things to be as predictable as possible. A good leader will keep you well-informed so you know about changes and developments before they happen and you know which direction you are moving in.

4. Leader support

In the study, the strength of the association between leader support and reduced psychological distress was astonishing. It was almost as strong as the association between physical distance from the bombing and psychological distress.

Experiencing trauma can makes us re-assess our lives and question our paths. A supportive leader will remind employees of their purpose by pointing out the alignment between their personal goals and career paths, reminding them of their "why."

We walk around every day with a mental picture of how the world works, etched in our minds by our life's experiences. This picture makes the world feel predictable and gives us a sense of control. Severe trauma destroys this sense of control.

Uncertainty is even bigger a stressor than physical pain. At the bottom of a team's hierarchy, the burden of uncertainty arising from severe trauma is compounded further by not having any control over decision-making, which is delegated to more senior members.

One of the greatest things you can do as a leader, is to give back control. You can't offer your employees control over their world at large, but you can convince them they control their world at work. Their world will start to feel a little less uncertain.