Final answer:
Heather's advice is problematic due to the lack of consideration for age-related differences in the effects of gratitude journaling, the need for studies with larger and more diverse populations, and because it ignores individual attribution habits which could affect intervention outcomes. Major depression should be addressed with various treatments tailored to the individual.
Step-by-step explanation:
Heather's advice that gratitude journaling can alleviate her grandmother's depression based on her study is problematic primarily because her study did not consider age-related differences in the effects of gratitude journaling. Heather's research was conducted with American teenagers, and since depression and its response to interventions like gratitude journaling can vary by age group, her grandmother might not experience the same benefits. Furthermore, while the sample size of 200 American teenagers is not negligible, it is still important to conduct additional studies with larger and more diverse populations and to include a control group to strengthen the body of evidence.
Moreover, the reformulated version of Seligman's study would suggest the importance of considering individual attribution habits, which could impact the effectiveness of interventions such as gratitude journaling. Factors like internal vs. external attributions, stable vs. unstable, and global vs. specific have been linked to depressive symptoms. Since these factors can change with age and experience, Heather's research may not be directly applicable to individuals in a different life stage
Lastly, major depression is a complex disorder with a variety of treatments available, including psychotherapy, pharmacotherapy, electroconvulsive therapy, and newer approaches like deep-brain stimulation. Therefore, while gratitude journaling shows promise, it should not be considered a standalone treatment for depression, particularly for different age groups without further evidence.