Which of the following is an example of a psychological factor in the biopsychosocial model?

In the biopsychosocial model, psychological factors encompass aspects related to an individual's mental and emotional state, including thoughts, feelings, and behaviors. Stress levels serve as a clear illustration of a psychological factor because they directly influence mental health and well-being. High stress can lead to anxiety, depression, and other mental health issues, while effective stress management can enhance coping strategies and overall psychological resilience.

Other options represent different categories within the biopsychosocial framework. Genetics pertains to biological factors that can predispose individuals to certain mental health conditions, while brain chemistry also relates to the biological underpinnings of mental health. Social support systems emphasize the importance of social environments and relationships, which fall under the social aspects of this model. Thus, stress levels distinctly represent the psychological dimension, making it the correct example in this context.