What term describes an uncomfortable sensation or strain that affects the mind?

The term that best describes an uncomfortable sensation or strain affecting the mind is stress. Stress can manifest as both emotional and physical responses to demanding or adverse situations, leading to a feeling of being overwhelmed or strained mentally. It is often associated with a range of sensations, including tension, anxiety, and pressure, though its primary definition pertains to the body's reaction to challenges or threats.

While tension is related and can refer to physical or mental strain, it does not encompass the full range of emotional and psychological factors involved in stress. Anxiety is more specifically related to feelings of unease or worry, often in the absence of a specific stressor, and depression is a mood disorder characterized by persistent feelings of sadness and loss of interest, which is distinct from the concept of stress. Therefore, stress as a term effectively encompasses the uncomfortable sensations associated with mental strain.