Depression
Mood disorders are less common than anxiety disorders in youth, but far more prevalent than ADHD. And depression is usually marked by serious difficulty concentrating across settings (including for things that were previously very interesting). A sullen teenager who is deeply self-critical about school performance would benefit from exploration of associated changes in mood, interests, energy, appetite, sleep, and for feelings of worthlessness, guilt, and suicidal thoughts. The PHQ9A is a simple, free screening instrument that is reasonable to use with every sick visit (and well-check) with your adolescent patients, given the risks of undetected and untreated depression. If your patient presents complaining of poor school performance, always screen for depression. As with anxiety disorders, comorbid ADHD is possible, but it is always recommended to treat the mood disorder first and then to assess for residual ADHD symptoms once the mood disorder is in remission.
Substance abuse
Adolescence is a time of exploration, and drug and alcohol use is common. While attentional impairment will happen with intoxication, occasional or rare use should not lead to consistent impairment in school. But when parents are more worried than their children about a significant change in school performance, it is important to screen for substance abuse. A child with a secret substance use disorder will often present with behavioral changes and deteriorating school performance and might deny any drug or alcohol use to parents. Indeed, stimulants have some street value and some patients may be seeking a stimulant prescription to sell or trade for other drugs. Regular marijuana use may present with only deteriorating school performance and no irritability or other noticeable behavioral changes. Marijuana is seen as safe and even healthy by many teenagers (and even many parents), and some youth may be using it recreationally or to manage difficulties with sleep, anxiety, or mood symptoms.
But there is compelling evidence that marijuana use causes cognitive impairment, including difficulty with sustaining attention, short-term memory, and processing speed, for as long as 24 hours after use. If a teenager is using marijuana daily after school, it is certainly going to interfere, in a dose-dependent manner, with attention and cognitive function. Sustained heavy use can lead to permanent cognitive deficits. It can also trigger or worsen anxiety or mood symptoms (contrary to much popular opinion).
Gathering a thorough substance use history is essential when assessing a teenager for difficulties with focus or attention, especially when these are accompanied by change in behavior and school performance. Remember, it is critical to interview these children without their parents present to invite them to be forthcoming with you.
History
While true ADHD should have been present throughout childhood, it is possible that the symptoms have become noticeable only in adolescence. For patients with very high intelligence and lower levels of impulsivity and hyperactivity, they might easily have “flown under the radar” during their elementary and even middle school years. Their difficulties with attention and focus might become apparent only when the volume and difficulty of schoolwork both are great enough that their intelligence is not enough to get good grades. That is, their problems with executive function, prioritizing, shifting sets, and completing tasks in a timely way make it impossible to keep up good grades when the work gets harder.
Your history should reveal a long history of dreaminess or distractibility, a tendency to lose and forget things, and the other symptoms of inattention. Did they often seem to not be listening when they were younger? Forget to hand in homework? Leave chores unfinished? Leave messes behind everywhere they went? These will not be definitive, but they do reassure that symptoms may have been present for a long time, even if school performance was considered fine until the workload got too large. If such problems were not present before puberty, consider whether a subtle learning disability could be impairing them as they face more challenging academic subjects.
If you have ruled out anxiety, mood, and substance use concerns, and helped them to address a sleep deficit, then you can proceed. It is worthwhile to get Vanderbilt Assessments as you would for a younger child. If they meet criteria, discuss the risks and benefits of medication, executive skills coaching, and environmental adjustments (extra time for tests, a less stimulating environment) that can help them explore academic challenges without the discouragement that ADHD can bring.
Dr. Swick is physician in chief at Ohana, Center for Child and Adolescent Behavioral Health, Community Hospital of the Monterey (Calif.) Peninsula. Dr. Jellinek is professor emeritus of psychiatry and pediatrics, Harvard Medical School, Boston. Email them at pdnews@mdedge.com.