The aim of this paper was to review the literature on adolescent psychiatric disorders related to the COVID-19 pandemic and lockdown. Stressful life events, extended home confinement, brutal grief, intrafamilial violence, overuse of the Internet and social media are factors that could influence the mental health of adolescents during this period. The COVID-19 pandemic could result in increased psychiatric disorders such as Post-Traumatic Stress, Depressive, and Anxiety Disorders, as well as grief-related symptoms. Adolescents with psychiatric disorders are at risk of a break or change in their care and management; they may experience increased symptoms. The COVID-19 pandemic and lockdown may have a negative outcome on the mental health of adolescents, although there is still no data on the long term impact of this crisis. Adolescents’ individual, familial, and social vulnerability, as well as individual and familial coping abilities, are factors related to adolescent mental health in times of crisis. Adolescents are often vulnerable and require careful consideration by caregivers and healthcare system adaptations to allow for mental health support despite the lockdown. Research on adolescent psychiatric disorders in times of pandemics is necessary, as such a global situation could be prolonged or repeated.