He has been speaking after the mental health charity Mind released new figures showing that half of 18-24s struggle in silence with their mental health.
In its national survey with the Lucy Rayner Foundation 55% of young people said they found it difficult to talk about their feelings when they were down.
Premier Lifeline's Jonathan Clark said: "Mental health problems occur as often as physical health problems, and if we're looking at society as a whole something around one in four of us will have some form of mental issue in a year.
"Particularly within certain friendship groups it can be very much the situation that you don't want to appear in anyway to be weak - and it may be perceived to be that if you're struggling with your emotions, struggling with your thinking, with your responses to what's happening in life, it may be perceived by others as you being weak or inadequate.
"But actually it's not, it's a normal thing for so many people to actually have - mental health problems occur as often as physical health problems."
Speaking to Mind, Becky Rayner, said: "After my sister Lucy took her own life we were shocked. She was so bubbly and outgoing. It just wasn't what you'd expect.
"There were no signs. None of us were clued up on mental health. We didn't understand. How are you supposed to understand if no-one ever talks about it?
"So now we think it is important to talk about our feelings and mental health, this was something Lucy found hard to do. You can't look at someone and say they have mental health issues.
"You have to speak to them, ask about it to understand and if we do, hopefully a few more people might recognise their symptoms and feel brave enough to ask for help."
Listen to Premier's Hannah Tooley speak to Jonathan Clark here: