Many of my clients are teenagers and preteens dealing with a wide variety of psychological issues. 

Some common presenting problems in this age-group are:

anxiety (including social anxiety and panic disorder)
depression
self-injury
relationship/social problems
academic stressors
sleep disorders
oppositional-defiance
ADHD
Aggression/irritability
social media/screen addiction
perfectionism and/or no motivation ("all or nothing" mindset.)

With teenagers and pre-teens, I tend to utilize dialectical behavioral therapy (DBT) and cognitive behavioral (CBT) techniques.  Research has found that outcomes are better with a group therapy component (to practice interpersonal skills, mindfulness, healthy thinking, and distress tolerance in a controlled environment), so I also offer a group for teenagers with rolling, on-going enrollment.

Family therapy/parent consultation is often indicated when working with teenagers (and minors in general).  However, confidentiality is essential to the therapeutic process, and something that I am mindful to uphold.  Therefore, I will provide family/parental consultation only if one of these two are true:  1)  The minor is in imminent danger of harming self or others, no "safety plan" is established, or the minor cannot be expected to comply with a "safety plan" due to psychological instability  2)  The minor has verbally agreed to discussions (and content of discussions) with parents.  #2 often happens with some encouragement from the therapist, but not always.  In the event that family consultation is indicated, but the minor is uncomfortable with his/her personal therapist providing the family therapy, I can provide (and consult with, when releases are signed) another family therapist.