Police say they are growing "increasingly concerned" for former footballer Clarke Carlisle, who has been reported missing.
Lancashire Police said the former Burnley player was last seen by a family member in Preston on Thursday afternoon.
The force believes he may have travelled to Manchester.
The former Professional Footballers' Association chairman, who made more than 500 appearances for nine clubs during his playing career, has a history of mental illness.
He launched a mental health charity called the Clarke Carlisle Foundation for Dual Diagnosis - a condition that has been described as "mental health problems co-occurring with drug or alcohol misuse".
The father-of-three remarried earlier this year and has worked to raise awareness of mental health issues.
His wife, Carrie Carlisle, tweeted a photo of him with the message: "Clarke's last known whereabouts was Manchester City Centre at 6am. If you see him please get in touch."
The 37-year-old was last seen wearing a black zip-up jacket, black T-shirt, blue jeans and Nike trainers.
He is described as afro-Caribbean, 6ft 4ins, of slim build and with tattoos on his arms.
He was last seen on the Flag Market in Preston at about 2.30pm on Thursday.
Detective Chief Inspector Steve Holgate said: "We are extremely concerned about Clarke and we would urge anyone who sees him or knows where he is to get in touch with us.
"We would also appeal directly to Clarke himself to contact us if he sees this appeal to let us know he is safe."
The former defender tried to take his own life in December 2014 when he jumped into the path of a 12-ton lorry on the A64, near York, while suffering from depression.
Anyone with information can contact police on 101 quoting log number 0235 of September 15.