Which of the following is an example of a CASE study?

a) a study using a controlled group design that includes independent and dependent variables to research effective eating disorder treatments
b) a study involving a positive correlation between age and anxiety
c) a study attempting to prove a causation between education levels and the onset of dementia
d) a study intensively examining one family's frequency of depression diagnosis that includes assessments or descriptions of depressive behaviors and treatment outcomes

Ans: d) a study intensively examining one family's frequency of depression diagnosis that includes assessments or descriptions of depressive behaviors and treatment outcomes