Final answer:
The belief that assessment findings in mental disorders reflect a person's cultural patterns best supports a nurse's patient advocacy efforts by ensuring culturally competent care.
Step-by-step explanation:
The belief that will best support a nurse's efforts to provide patient advocacy during a multidisciplinary patient care planning session is that assessment findings in mental disorders reflect a person's cultural patterns. This understanding allows the nurse to appreciate the cultural context of a patient's experience with mental illness and ensures that care planning is tailored to meet the patient's individual needs. Recognizing the influence of culture on mental health can help the nurse in advocating for culturally competent and sensitive care, which is crucial for effective communication and intervention.