Depression and Chocolate Consumption

In a study of 900 adults in California who weren't taking antidepressants found those who screened positive for depression ate about eight servings of chocolate per month, while those without depression ate just five servings a month, a statistically significant difference. The research was published in the Journal Archives of Internal Medicine (2010;170(8):699-703)
Is it chocolate giving them depression or people seeking out mood foods . On a light hearted note at least this study may help identify people more likely to be depressed by observing their chocolate consumption.