What symptom is least likely to be associated with major depressive disorder?

The symptom that is least likely to be associated with major depressive disorder is enhanced concentration. In individuals experiencing major depressive disorder, cognitive function is commonly impaired, which may manifest as difficulty concentrating, making decisions, and remembering details. This cognitive challenge often contributes to the overall feeling of being overwhelmed and can affect a person's ability to engage in daily activities effectively.

In contrast, a pessimistic outlook, social withdrawal, and vegetative symptoms such as changes in sleep and appetite are all well-documented features of major depressive disorder. A pessimistic outlook reflects the negative thought patterns commonly found in depression, while social withdrawal indicates a reduced interest or pleasure in activities and a desire to avoid social interactions. Vegetative symptoms include disturbances in sleep and appetite, which are also prevalent in depressive episodes.

Therefore, enhanced concentration stands out as the symptom that does not align with typical presentations of major depressive disorder, as it contrasts sharply with the cognitive impairments often experienced by affected individuals.