A Calgary mother says her daughter has slipped through the cracks because she suffers from a mental illness and has a developmental disability.

Carma Mahoney's 23-year-old daughter has been on and off the streets and involved in drugs and prostitution.

"I'm constantly scared something terrible will happen to her," says Mahoney.

Jenny, who is developmentally delayed, was diagnosed with borderline personality disorder when she was 11.

Mahoney says she has yet to find the right treatment or housing support for her daughter.

"I don't understand how the system can continually put her in jeopardy."

Mahoney says the last time Jenny was released from hospital she was put in an apartment with no support.

"I'm just waiting for the next disaster and hopefully it doesn't cause her to lose her life or harm someone else, because you don't know ... when that may happen," she said.

Programs often work independently

Bruce Uditsky with the Alberta Association for Community Living hears from many families struggling to find the right help.

"We have still a vast distance to go," he says.

"There just aren't enough adequate resources for families in this situation."

Uditsky says the mental health system and programs for people with developmental disabilities work independently for the most part, and often workers on one side are not trained to deal with the other.

"When acquiring mental health services, they may not have the staff that have the knowledge and expertise as to how to communicate effectively with someone with cognitive challenges."

Uditsky also says there is a shortage of psychiatrists who specialize in treating people with developmental disabilities.

"We see hundreds of families every year in all kinds of difficult circumstances, including numbers that fall through the cracks," he said.

Join the conversation online. Tag your tweets with #cbcmentalhealth to connect to others talking about youth and our overburdened mental health system.

With files from CBC's Jennifer Lee