Stacey Ruth Phillips, 23, of Fossway, has not been seen since leaving her house at 11am on Saturday 15 September 2012.
Officers are concerned for Stacey’s wellbeing and fear that she may present a danger to herself after a recent bout of depression.
An extensive search for Stacey has primarily concentrated in the York area, but she is known to have links to the Manchester area and may have travelled via train.
Stacey is described as white, 5ft 2in tall, heavy build with very long dark brown dreadlocked hair which is tied up in a bun. She was wearing a long black cardigan with pockets but no buttons, blue knee-length leggings and white plimsolls with lace netting.
PC Steve Skeoch, of the York Safer Neighbourhood Team, said:
We are hoping that Stacey sees or hears this urgent appeal and makes contact with the police or her family as soon as possible.
Everyone is worried sick, we just need to know that Stacey is safe and well.
If anyone has seen Stacey or has possibly noticed a woman matching her description, please pass the information onto the police to assist the missing from home inquiry.
If you can help, call North Yorkshire Police on 101, select option 1, and pass information to the Force Control Room.
Please quote reference number 12120155106.