Situation: The nurse is assigned to clients with personality disorders on an adult psychiatric unit. A 26-year-old woman has been on the unit for 2 weeks. At the weekly team meeting, the day staff describe her as grateful and cooperative, while the night staff describe her as hostile and demanding. The two shifts now disagree about her care. Which explanation BEST accounts for this?

Splitting, a hallmark of borderline personality disorder, divides people into all good or all bad and can set staff groups against each other. The response is one consistent plan agreed and applied by every shift. Her behavior differs by who is present, not by time of day, and the conflict arises from her pattern rather than from charting or one group's feelings.

Core mechanism
The most useful way to understand this situation is through splitting, a primitive defense mechanism commonly seen in borderline personality disorder. Splitting means the person cannot hold both positive and negative qualities of another person—or of herself—in mind at the same time. Instead, people are categorized as all good or all bad. In an inpatient unit, this often plays out as one shift being idealized while another shift is devalued. The day staff experience her as grateful and cooperative; the night staff experience her as hostile and demanding. The conflict between the two shifts is therefore not primarily a documentation problem or a difference in the staff’s emotional reactions—it is the patient’s interpersonal pattern being enacted across the team ^[1].

Splitting can set staff groups against each other because each shift only sees one side of the patient’s presentation. The day staff may feel protective of a “pleasant” patient, while the night staff may feel blamed for being “too harsh.” This is a classic sign that the team is being split, and it requires a unified response rather than a debate about which shift is right.

Why the other options are less accurate
Mood cycling by time of day would imply a biological or circadian pattern, such as diurnal variation in depression. However, the description points to behavior that changes according to who is present, not according to the clock. The day and night staff are different people, and the patient’s behavior shifts with the interpersonal context, which is more consistent with splitting than with a mood episode .

Inconsistent charting could create disagreement about a patient, but the scenario describes direct observations by each shift, not a failure of documentation. The staff are not misreading the chart; they are witnessing different behaviors. The conflict arises from the patient’s pattern, not from recording errors.

Stronger countertransference in the night staff is a possible contributor, but it is not the best explanation. Countertransference refers to the staff’s emotional reactions to the patient. While the night staff may indeed feel frustrated, the more complete explanation is that the patient is inducing different reactions in different groups through splitting. The problem is not located only inside one shift’s feelings; it is a team-level dynamic ^[1].

Clinical application
The priority intervention is to create one consistent plan that every shift agrees on and applies in the same way. This reduces the patient’s ability to play one group against the other. Team communication should focus on observable behaviors and shared limits, not on which shift is “nicer” or “stricter.” In personality disorders, rigid and inflexible interpersonal patterns are a core feature, and treatment works best when the environment is predictable and consistent .

Watch out! When a patient is described very differently by different staff groups, consider splitting before assuming a mood disorder or a documentation problem. Key point! The correct nursing response is a unified, consistent care plan applied across all shifts, not taking sides in the staff disagreement.