Final Answer:
Of the 21% of US mothers diagnosed with postpartum depression (PPD), the percentage of women with major depressive disorder (MDD) who had comorbid anxiety disorders, primarily generalized anxiety disorder (GAD), stood at approximately 64%.
Step-by-step explanation:
In the Landmark Study of 10,000 US Mothers, 21% were diagnosed with postpartum depression (PPD). Among these, a subset was identified with major depressive disorder (MDD). Research suggests that among individuals with MDD, around 60-70% experience comorbid anxiety disorders. Therefore, to determine the percentage of women with MDD and comorbid anxiety disorders within the population diagnosed with PPD, we calculate 21% of the mothers (those with PPD) and then estimate 60-70% of this subset to gauge the range of comorbidity.
21% of 10,000 US mothers diagnosed with PPD equals 2,100 mothers. Considering the estimated range of 60-70% prevalence of comorbid anxiety disorders among those with MDD, the calculation is as follows:
60% of 2,100 = 1,260 mothers (lower estimate)
70% of 2,100 = 1,470 mothers (higher estimate)
Therefore, the estimated percentage of women with MDD and comorbid anxiety disorders, primarily GAD, falls approximately between 60% and 70% within the subset diagnosed with PPD. Considering the mid-range value between these estimates, it's inferred that around 64% of women with MDD among those diagnosed with PPD likely experienced comorbid anxiety disorders, with GAD being the most commonly associated anxiety disorder.