The founder of Pieta House has said that around 150,000 people are expected to take part in the annual 'Darkness into Light' event across Ireland overnight.
Speaking on RTÉ's Morning Ireland, Senator Joan Freeman said with people also getting involved abroad, the overall numbers are likely to be closer to 200,000.
The "symbolic" 5km walk promotes suicide prevention and looks to tackle the stigma that leads people to the doors of Pieta House centres.
Walks are scheduled to take place around Ireland from 4.15am, although by that time events will have been held in New Zealand, Australia, South Korea and China.
"So many families have been touched by suicide," Ms Freeman said.
"It is not just about thousands of people walking, it is about coming together as a country, and all talking about the same topic."
Senator Freeman also spoke about the need to improve mental health services for children.
"We have to stop having children placed in adults psychiatric units," she said.
"For a child to go into that same unit is daunting, frightening and can be catastrophic. Mental health services for children will not change unless we get people of Ireland behind us."
She said they will be holding a public consultation day in the coming weeks where they are inviting people to tell their story.
She made an appeal to parents and guardians who have had experience in mental health services to contribute to the Seanad Public Consultation Committee that has been set up to make recommendations on new children's mental health legislation.
The closing date is next Friday.
