Major Depressive Disorder: Epidemiology and Diagnosis
The most accurate statement is that diagnosis often occurs in late adolescence and early adulthood. The patient's presentation with six months of persistent sadness, hypersomnia, loss of interest, appetite changes, and fatigue meets diagnostic criteria for Major Depressive Disorder (MDD), and the epidemiological facts clearly refute the other options presented.
Why the Other Statements Are Incorrect
Lifetime Prevalence is NOT 5%
- The lifetime prevalence of MDD is approximately 17%, not 5% 1
- MDD affects one in six adults in their lifetime, making it substantially more common than the 5% figure suggested 2
- This higher prevalence underscores MDD as a major public health concern, projected by WHO to become the second leading cause of disability worldwide by 2020 1
Women Are MORE Affected Than Men
- MDD occurs approximately twice as often in women compared to men 2
- This 2:1 female-to-male ratio is well-established across multiple populations and age groups 2
- The statement suggesting men are more likely to have MDD is factually incorrect and contradicts established epidemiological data
Genetic Factors DO Play a Significant Role
- The heritability of MDD is estimated at approximately 35% 2
- Genetic factors represent a substantial component of MDD etiology, though the disorder is multifactorial 2
- The statement that genetic factors play no significant role is demonstrably false 2
Diagnostic Confirmation in This Case
The patient meets DSM-5 criteria for MDD, which requires five or more symptoms present during the same 2-week period (this patient has 6 months), with at least one being depressed mood or loss of interest 3, 4:
This patient demonstrates:
- Persistent feelings of sadness (depressed mood) 4
- Loss of interest in daily activities (anhedonia) 4
- Hypersomnia 4
- Loss of appetite 4
- Fatigue or loss of energy 4
The 6-month duration far exceeds the minimum 2-week requirement and indicates chronicity 3, 4.
Age of Onset Considerations
Late adolescence and early adulthood represent the typical age range for MDD onset 3:
- Depression screening is now recommended for all adolescents between ages 11 and 21 years 3
- Serious mood disorders including MDD commonly present during adolescence with symptoms that may include irritability rather than classic depressed mood 3
- The peak incidence occurs during this developmental period, making this the most accurate epidemiological statement among the options provided