Which of the following is NOT a medical condition associated with depressive symptoms?

Chronic obstructive pulmonary disease (COPD) is primarily a respiratory condition characterized by airflow limitation and is usually associated with symptoms such as chronic cough, wheezing, and shortness of breath. While individuals with COPD may experience depressive symptoms, the condition itself is not directly associated with the biological mechanisms that typically lead to depression.

On the other hand, other listed conditions have well-documented physiological links to depressive symptoms. For example, hypothyroidism can lead to mood disturbances due to low thyroid hormone levels, which can affect overall energy and mood regulation. Similarly, Cushing syndrome results from excessive cortisol, which can significantly impact mood and has been linked to depressive disorders. Parkinson's disease, a neurodegenerative disorder, can affect the brain areas that regulate mood and emotions, leading to depression as a common non-motor symptom.

Therefore, among the choices, COPD stands out as not being a medical condition inherently linked to the development of depressive symptoms, making it the correct selection for this question.