Video report by ITV News Scotland Correspondent Peter Smith
Scotland's drug problem has become a battleground for politicians ahead of May's election.
The SNP, Labour and Conservatives have promised to tackle the growing issue within the country.
Footage of users in Glasgow injecting heroin into their necks and thighs was shown to Scottish Conservative leader Douglas Ross, who admitted the video was "disturbing" and has vowed to address the root causes of the issue.
'Those images are really troubling': Douglas Ross on the reality facing drug users in Scotland
But addicts, former addicts and rehabilitation staff have called on the next government to ensure there is more joined-up thinking between mental health and drug rehabilitation clinics.
'People don't become addicts because they're happy': Former users call for simplier way of getting users into the services they need
'I want to go into rehab but I can't': How addicts are trapped in a cycle of addiction