Final answer:
The prevalence rate over a 12-month period for major depressive disorder is approximately 7.8%.
Step-by-step explanation:
The prevalence rate of major depressive disorder (MDD) is determined by the number of individuals who meet the criteria for MDD during a specific time frame, typically over a 12-month period. To calculate this rate, we divide the number of individuals with MDD by the total population and then multiply by 100 to get a percentage. In epidemiology, this formula is represented as:
Prevalence Rate = (Number of cases of MDD/Total population) x 100
The prevalence rate for MDD is crucial for understanding the burden of the disorder on the population's mental health. It reflects the proportion of individuals affected within a specific timeframe and serves as a key metric for public health planning and resource allocation.
In the case of major depressive disorder, the prevalence rate of 7.8% indicates that, on average, 7.8 out of every 100 individuals in the population are affected by MDD over a 12-month period. This statistic underscores the significance of MDD as a public health concern and emphasizes the need for effective prevention, intervention, and treatment strategies to address the mental health challenges faced by a substantial portion of the population.