Harry's candid comments will help us to deal with grief
When I started my psychiatric training we were taught the five stages of grief. The bereaved, we were told, would shift through "denial, anger, bargaining and depression" like the gears of a car, before eventually ending up with the right outcome, namely "acceptance".
This turned out to be good in theory, but more complex in real life. There is no right way to do it. Like love and other emotions, everybody experiences it in different ways.
So, to have Prince Harry discussing so openly the impact of the death of his mother on his mental health will make a huge difference to the way we discuss grief.
Grief is uncomfortable, unpleasant, and physically painful, but it is also a part of normal life - all of us will experience it.
But sometimes it can be so prolonged or intense that it can lead to mental health problems.
Certain factors will also make a loss even more difficult to bear. You don't really need to do a lot of research to know that losing a parent at a young age is one such circumstance.
Studies of children in this situation have found that three years later, while most have improved, 10pc show no reduction in distress.
Adolescence is a difficult time, even without bereavement. Displaying emotions in public can make teenagers feel awkward, and it is more difficult to be physically comforted.
Most of all, it's a time when you are particularly sensitive to what others think of you.
There may be many things you do in the short term to lessen the pain, such as repress memories, not talk about the person you have lost, or avoid anniversaries.
However, we know that if this is done for a long period it can sometimes prolong the grief and its consequences and make things even more complex.
Prince Harry has spoken eloquently about the problems of over-diagnosing and over-labelling, and we have the data to support it. Grief and bereavement are not in themselves mental illnesses and we should not treat them as such.
Talking about our grief to the right person and at a time of your choosing - as the Prince says he has done - is good when you are ready.
What Prince Harry is saying is simple and true. Talking about this is just normal.
Prof Simon Wessely is president of the Royal College of Psychiatrists in the UK