The spotlight has been put on missing people this week for National Missing Persons Week.

Over 8,500 people are reported missing in Victoria each year, with most people found within a week.

More than half of those reported missing between June 2012 and June 2013 were under the age of 17.

Some, such as Ballarat teenager Donny Govan who went missing while on a camping trip in Echuca last year, and 12-year-old Terry Floyd, who was last seen in 1975, don't return home.

Bendigo police's Sergeant Jason Bourke said the majority of missing person cases were youths in residential care programs.

He said many of them regularly went missing and returned within a few days.

"They'll turn up when they are ready," he said.

"Very few and far between do not turn up. But it does happen."

Castlemaine police's Sergeant Rohan Scott said most cases were young people who returned within two to five days.

"It is often the case. They leave for all sorts of reasons. A fair percentage of that are reoccurring people."

Sergeant Scott said they treated every case the same, regardless of whether it was someone who regularly went missing or not.

"You can't assume anything. You have to treat it as you did the first time. The risk factors are still there."

The Salvation Army's Dr Bruce Redman said young people went missing for many reasons, including family violence, stress from school or bullies.

He said mental illness tended to be a common link between people who are missing.

"Teenagers may need to get away and get their space, especially if there is pressure with school or in social situations or a relationship break-up. Family violence is a problem for a lot of kids.

"They leave for their own safety, because they are worried about being a victim of violence themselves. It's a complicated issue," Dr Redman said.

He said those who went missing regularly were still at risk of disappearing for a longer time.

"If there are regular patterns of small absconding, people may be slow to react.

"You could get use to the fact they are missing, then all of a sudden they are missing for a day, then a week, then a year."

Learn more at www.missingpersons.gov.au