Which of the following is a mental health behavioral warning sign?

Suspiciousness is a notable mental health behavioral warning sign. It can indicate that an individual may be experiencing difficulties with trust, perception, or reality, often associated with various mental health disorders. This behavior could manifest through a heightened sense of paranoia or an unwarranted mistrust of others, which can affect relationships and overall functioning.

In contrast, chronic fatigue, increased physical activity, and enhanced social interactions may not inherently signal mental health concerns. Chronic fatigue can arise from various physical or psychological conditions and does not specifically suggest a mental health warning. Increased physical activity can often be a positive indicator of improved mood or health, rather than a negative behavioral sign. Enhanced social interactions typically suggest a healthy engagement with others and, therefore, would not be characteristic of a warning sign within mental health contexts.