Name a common diagnostic tool used in mental health assessments.

The Beck Depression Inventory (BDI) is a widely used diagnostic tool specifically designed to assess the severity of depression in individuals. It consists of a series of questions that gauge various symptoms and attitudes related to depression, allowing clinicians to quantify the patient's mood and experiences. This inventory is particularly beneficial because it has been extensively validated and provides a clear metric for tracking changes in a patient's depressive symptoms over time. It is commonly used in both clinical and research settings, making it a cornerstone of mental health assessment.

In contrast, other tools mentioned, like the IQ Test, primarily assess cognitive functioning rather than mental health directly. The Personality Assessment Inventory (PAI) evaluates a broader range of personality features and psychopathology but isn't specifically focused solely on depression. The Visual Analog Scale (VAS) is typically used for measuring subjective sensations such as pain rather than mental health disorders. Thus, the BDI stands out as the most relevant and widely recognized tool for assessing depression specifically within the context of mental health evaluations.