Final answer:
The student is experiencing symptoms consistent with obsessive-compulsive disorder (OCD), characterized by intrusive thoughts and repetitive behaviors. Engaging in repetitive checking of the car door is a compulsion done in response to the obsessive thought that the door may not be locked. A thorough assessment and treatment plan by a mental health professional is needed.
Step-by-step explanation:
This medical student is experiencing symptoms consistent with obsessive-compulsive disorder (OCD). OCD is a mental health disorder characterized by intrusive thoughts and repetitive behaviors. The student's repetitive checking of the car door is an example of a compulsion, which is done in response to the obsessive thought that the car door may not be locked.
People with OCD often engage in these behaviors to relieve anxiety or prevent a feared event from occurring. In this case, the student is worried about the car door being unlocked and feels compelled to repeatedly check it.
A thorough assessment by a mental health professional, such as a psychiatrist or psychologist, is necessary to formally diagnose OCD and develop an appropriate treatment plan. Treatment may include cognitive-behavioral therapy (CBT) and/or medication.