The nurse is working in a clinic and sees a resident of a long-term-care facility, age 82 years, who has come in to be checked by her physician. The caregiver accompanying her reports that the client has been displaying the following: drowsiness, excessive sleeping, decreased attention span, irritability, and signs of depression. The client’s daughter and family, who usually visit her, moved away from the area 6 weeks ago due to the husband’s job. The nurse suspects which problem?