According to a CYF report given to the coroner, Jack had a troubled history and presented many challenges.
He was in residential care between the ages of 12 and 16 and was eventually discharged to a care and protection residence before returning to his mother's care.
After leaving residential care, Jack continued to see a social worker and CYF helped co-ordinate assistance from external providers, the CYF report said.
Coroner Smith said that after Jack's death Ms Lindsay highlighted certain areas where she perceived support systems failed to address problems, or to provide her son with the support she thought was required.
Ms Lindsay said she believed there was a gap within the systems around Jack's age of 16 to 18 where most agencies withdrew as young people reached supposed adulthood.
Coroner Smith said Jack's case was not dissimilar to other cases he had dealt with regarding young people who suffered complex medical mental health issues and became subject to state intervention through CYF.
"I understand the complexity that CYF personnel have when dealing with this situation and again the limitations that can occur when a person reaches the somewhat arbitrary age of 17.
"I accept that CYFS have a statutory limitation at the age of 17, but there are, in certain cases, options of assistance that can continue."
He said in cases such as this, these young people "feel like they have been turned adrift".
Coroner Smith said while in Jack's case there was some continued support, it was not enough.
"I have stated previously, 17 is far too young to cut these young people adrift."
Comment from Child Youth and Family was being sought.
