Which symptom is a warning sign for individuals diagnosed with borderline personality disorder?

Severe mood swings are a prominent warning sign for individuals diagnosed with borderline personality disorder (BPD). This disorder is characterized by significant emotional instability and intense fluctuations in mood, often causing individuals to experience feelings that can change rapidly and without clear cause. These mood swings can lead to impulsive behaviors, difficulties in relationships, and challenges in managing one's sense of self. Recognizing severe mood swings as a symptom is crucial for timely intervention and support for those living with BPD.

The other options do not accurately reflect the hallmark symptoms of BPD. Lunar phases influencing behavior does not have a scientific basis in relation to BPD symptoms. Extreme shyness is more commonly associated with social anxiety disorder rather than BPD, which is characterized by interpersonal challenges and fear of abandonment. Compulsive disorder tendencies, while they may appear in co-occurring disorders, are not a defining characteristic of borderline personality disorder itself.