An international team of scientists say the way teenagers' brains are wired may help predict whether they will develop drug problems in the future.
The team looked at adolescents who were generally more impulsive than their peers - a trait sometimes linked to the misuse of drugs.
They found teenagers who had a particular pattern of activity on brain scans were more likely to misuse drugs.
The early work appears in the journal Nature Communications.
Scientists asked 144 adolescents who had not previously used recreational drugs to fill in questionnaires and take part in behavioural tests to assess how impulsive they were and how attracted they were to trying new things.
Researchers then conducted a range of brain scans, while asking the adolescents to carry out tasks that could win them cash prizes at the same time.
The tests were designed to look at how particular parts of the brain responded to the prospect of getting a reward.
They found those teenagers who had less nerve activity in these brain areas during these tasks, were more likely to have drug problems two years later.
One theory behind this, the scientists say, is that teenagers who are more likely to take drugs have less motivation for traditional rewards like money, and more for less conventional rewards.
Prof Brian Knutson, at Stanford University, says he hopes with more work, these types of tests could help identify vulnerable teenagers who could be offered help before problems arise.
Meanwhile Prof Derek Hill, of University College London, said the study was "interesting" with carefully collected and analysed data.
But he cautioned that the methods used in the study were still experimental.
He added: "It is therefore important that results like this are replicated in separate studies before the results in this paper should be used to change the way these young people are diagnosed and treated."