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Signs of Teenage Substance Use

Parents must notice the signs of teenage substance use.

Whether parents like it or not, their children grow up in an increasingly drug-filled world. We live in a society that encourages the use of chemical substances for sickness and for health, for pleasure and for performance, for relief and for escape.

In addition to the big three—alcohol, nicotine, marijuana—there are more varieties of legal and illegal psychoactive (mood- and mind-altering) drugs available to people today than at any time in human history. Huge legal and illegal profits mean that mass availability of these drugs is never going to go away as supply encourages more demand and demand encourages more supply.

No wonder so many adolescents fall prey to the temptations of substance use. By the end of high school, most students have at least experimented with one or more of the big three. And as has been explained in an earlier post about the final stage of adolescence, Trial Independence (ages 18-23), the most alcohol and drug intense stage of adolescence, comes last.

Adolescence is a process of separation from childhood and family, differentiation from how one was as a child, and experimentation with new (often forbidden) experiences to grow. Experimentation is the motivation that begins most substance use. But how are parents to know if their adolescence is engaged in some level of substance use?

In most cases, it will not be because the teenager has told. It will be because he has gotten caught. Then they will receive the standard lie: "This is the first time I tried anything and I will never do it again!" No. The first time caught is rarely the first occasion of use. And once he has started, he is more likely to use again. Hereafter, he will be more careful to conceal what is going on.

When adolescents start significant substance use, they usually do not confess it to a parent in words; they betray it by their actions. So parents need to know what behaviors to look for. To begin, they should pay attention to uncharacteristic changes in their son or daughter's behavior.

First, consider some of the general warning signs on the list that follows. Parents should notice:

  • When smart kids make stupid decisions.
  • When good kids act badly.
  • When truthful kids lie.
  • When mindful kids can't remember.
  • When conscientious kids become indifferent.
  • When even-tempered kids develop mood swings.
  • When kids with little money have more to spend.
  • When academically achieving kids fail.
  • When dedicated kids lose interest.
  • When communicative kids shut up.
  • When open kids become secretive.
  • When nice kids act mean.
  • When responsible kids act irresponsibly.
  • When reliable kids default on their agreements.
  • When motivated kids start not to care.
  • When careful kids act careless.
  • When obedient kids break rules or laws.
  • When focussed kids have accidents.
  • When healthy kids become run down.

None of these changes individually is a guarantee of substance use; however, over time a pattern combining a number of these alterations should be cause for possible concern.

What makes detection of teenage substance use particularly difficult is the similarity that many signs of substance use have to normal changes that are often part of adolescence. Therefore, it is helpful for parents to discriminate between overlapping and non-overlapping signs of use.

Overlapping signs (typical both for adolescence and substance use) include:

  • Unpredictable mood swings
  • Less willingness to communicate
  • More insistence on privacy
  • More volatile in conflict
  • More easily distracted, daydreaming, inattentive
  • More disorganized and unfocussed
  • More drawn to drug and counterculture entertainment
  • Less cooperative at home
  • More counterculture interests and dress
  • More manipulative to get needs met
  • Disinterested in what traditionally mattered
  • Disengagement from old friends you know to new ones you don't
  • More forgetful
  • More rebellious and argumentative
  • Urgent focus on the present, unconcern for the future
  • Avoiding and evading issues parents want to discuss
  • Not caring about doing schoolwork

All of these changes can accompany normal adolescence; however, they can also be markers for substance use.

Non-overlapping signs (often for substance use only) include:

  • Money, or valuables that can be pawned, missing from other family members, unexplained charges on parental credit cards
  • Regularly caught smoking cigarettes or using spit tobacco
  • Drug paraphernalia like rolling papers, pipes, clips, tubes, foil, butane lighters, found among belongings
  • Full or empty bottles, cans, seeds, pills or substances in powdered form found in bedroom, pockets, backpack, or car
  • Bottles of alcohol disappear from parents liquor supply or are diluted
  • Pills missing from psychoactive prescriptions in medicine chest
  • Dramatic change in eating or sleeping habits, either much more or much less
  • New friends who avoid introduction, who are not named, who are older, or who are always met away from home
  • Major house rules like curfew and car use continually broken despite promises to the contrary
  • Medical emergency precipitated by excess chemical use
  • Mysterious phone calls received, particularly late at night, and when parents answer someone hangs up or declines to give a name
  • Teenager lies about inconsequential events and insists on lying about having lied when caught in a lie
  • Drug or alcohol violations of the law
  • Steady decline in school performance marked by tardiness to class, lack of attendance, homework/classwork not completed, conflicts with school authorities
  • Decline in physical condition such as constant fatigue, incidents of acting uncoordinated, unclear speech, confused thinking, bloodshot eyes, run-down appearance, coughing or runny nose with no sign of being sick, unexplained bruises or what could be injection marks on the body
  • In possession of unexplained amounts of money
  • Has a reputation for drug use among peers or for running with a using or partying crowd
  • Dress and person frequently smell of smoke and alcohol
  • Asked about possible substance use, teenager overreacts to question with explosive hostility

What should parents do? Monitor the young person's decision-making more closely. Decisions that create problems or cause trouble should catch your suspicious attention. When in doubt, check it out. Denial is the enemy in hiding because, whether by teenager or parents, it only enables further use. Hope is the most common form of denial for them all. The teenager hopes that parents won't notice, and parents hope that by his denial the teenager is really telling them the truth so they don't have to face a family problem.

But just suppose sufficient numbers of general, non-overlapping, and overlapping signs of substance use have been identified by parents to cause them concern, but their son or daughter refuses to answer questions they ask.

"Anything goes wrong," charges the teenager, "and all you think about are drugs! Well I'm sick of not being trusted! Just leave me alone!"

What should parents do now?

The answer is, use grounds for suspicion to look for harder evidence.

"You searched my room? You took my stash! That's stealing! I could have you arrested! That's violating my right to privacy!"

"No," explain the parents. "Your privacy is a privilege earned by our trust; it's not a right. And when you abuse that privilege by using it to conceal destructive and unlawful behavior, we have the right to search and seizure, and that's what we have done. Now let's talk about what's been going on and what needs to be done."

For more about parenting adolescents, see my book, SURVIVING YOUR CHILD'S ADOLESCENCE (Wiley, 2013). Information at

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