Final answer:
The symptoms of repeatedly checking if the door is locked and excessive cleaning suggest Obsessive-Compulsive Disorder (OCD), which involves persistent obsessions and compulsions.
Step-by-step explanation:
The symptoms described in the scenario, such as going back to check if the door is locked multiple times and frequently cleaning the room even when it isn't dirty, are indicative of Obsessive-Compulsive Disorder (OCD).
This condition is characterized by persistent and repetitive thoughts (obsessions) that lead to behaviors (compulsions) the person feels compelled to perform, which in this case are repeated checking and cleaning. These repetitive actions are performed in an attempt to reduce the anxiety associated with the obsessions.