Following any furlough from a residential placement. At intake to probation. However, for ongoing substance testing, random specimen collection is recommended. Random or unscheduled testing reduces the possibility that youth will attempt to schedule their drug use to avoid detection. TOP Frequency of Testing Youth should be tested randomly and frequently enough to detect and deter illicit drug use.
Some drugs typically remain in the system longer than others.
Table 7 indicates the approximate duration of detectability of selected drugs. As the table shows, a youth using marijuana might be tested less frequently than one who is using amphetamines. These are general guidelines only. Scientific issues in drug testing. If the person collecting specimens does not personally know each youth being tested, a process for identification of youth should be implemented to ensure the sample is from the appropriate individual.