The outbreak and the quick expansion of SARS-CoV-2, from December 2019 to today, has forced countries around the world to resolve virus containment measures in order to slow down the contagion curve. Between these measures, the situation of lockdown, and the isolation or limitation of social contact between the citizens, there has been an unknown psychological impact. Certain groups (the elderly, children and teenagers, and the clinical population, for instance) arouse serious fears among professionals due to their greater vulnerability and ignorance regarding the short- and long-term consequences. The main purposes of this work are first of all to evaluate the consequences of the lockdown in children and teenagers diagnosed with attention deficit hyperactivity disorder (ADHD), sleep-related problems, and problems with executive functions. Secondly, we aim to compare the effects produced with respect to the previously mentioned variables with normotypic subjects; that is to say, between a group that was subject to lockdown and another group that was not confined. The findings show that the clinic confined group had high levels of state anxiety and problems with sleep and executive functions; differences could also be seen between the two groups, with the confined ADHD group being more negatively affected in all measured variables.