Comments on abstract, title, references Abstract: The abstract gives a wonderful overview of the paper is about. It describes what telomeres are, their significance, what psychological states meditation positively affect (namely neuroticism and perceived control) and how changes to these psychological states enhance telomerase. The research question is clearly stated: "Therefore, we investigated the effects of a 3-month meditation retreat on telomerase activity and two major contributors to the experience of stress: Perceived Control (associated with decreased stress) and Neuroticism (associated with increased subjective distress)." Yes, the research methodology is clearly outlined. Yes, the results and conclusions align with the aim. Yes, the title does convey the main idea.

The title is very descriptive of what the entire papers about. It does sound interesting, and it didn't catch my attention. It is an accurate representation of the paper overall

Comments on introduction/background

1. Is it clear what is already known about the topic:
2. Yes, it is made very clear. The researchers give a background on what is known about telomerase, how the specific variables of perceived control and neuroticism could be mediators in telomerase activity, how meditation affects a perceived control and neuroticism.
3. The authors give a rather extensive background on each of these areas come including up-to-date (for the time) publications to support their claims.

4. The researchers also point out specific gaps in the research (i.e. how mindfulness and its effects on telomerase have not been assessed) which then make it clear why the researchers conducted this study in the first place.

5. Is the research question clearly outlined:

6. Yes, it is outlined succinctly and clearly. The authors discuss how telomerase activity is shortened due to psychological stressors, and how Buddhist meditation has been shown to increase wellbeing. Even proceed to explain that the variables of perceived control and neuroticism contribute to psychological stress.

7. They then explain that they want to investigate how meditation affects perceived control and neuroticism, and as a result, telomerase activity.

8. Is the research question justified given what is known about the research: -Yes, the research question is very justified. Firstly, the topic of telomerase is "hot" in the literature, as is mindfulness and stress. The importance of enhancing telomerase activity is also very popular. Mindfulness' affect on enhancing health by decreasing stress is also very relevant today. Coupling these two topics feels like a natural and justified research question that certainly adds to the growing body of work in both of these areas.

Comments on methodology

1. Is the process of subject selection clear:
2. Yes the process of subject selection is clear.
3. I do feel that the subjects chosen for the study are not as broad as I would have liked.
4. They chose subjects through advertisements in Buddhist magazines and Buddhist websites, limiting the scope of subjects to those who are either Buddhist, or inclined toward Buddhism, so I question if the same effects would be observed in those not inclined toward Buddhism.
5. The subjects were also at a meditation retreat and many already had meditation experience. Would the same effects be observed outside of the retreat setting buy those not experienced in meditation?

6. There was a control group that was assessed at the retreat center (to control for locational variables like altitude etc.) but spent the rest of the time at their homes, engaged in their daily lives.

7. Are the variables defined and measured appropriately:

8. Yes, the variables are defined and measured appropriately.
9. The researchers explain how they measured all variables: telomerase activity, mindfulness, perceived control and neuroticism.

10. the researchers go in to great detail about the ways they measure the variables, and why they were valid measures.

11. Are the study methods valid and reliable:

12. Yes, the authors give details about the study methods and measures, and explain why they are valid measures of the particular variables.

13. Is there enough detail in order to replicate the study: Yes, there is great detail and this study would be easily replicated.

Comments on data and results

1. Is the data presented in a appropriate way:
2. Yes. The tables and charts were very helpful overall. There were some tables that seemed a little confusing, but the text did clear them up
3. The text with the results helped to clarify some of the tables that were not as clear
4. yes I'm clear about what was statistically significant and why
5. yes I was clear about what was practically important and relevant to the overall population

Comments on discussion and conclusions

• the results are discussed from multiple angles and placed into context. For example, the researchers discussed how meditation relates to all variables and how they are beneficial in each matching.
• the conclusions answer the aims of the study which sought to find out to what extent psychological mediators (neuroticism, perceived control and purpose of life) are altered positively by meditation and how those effect telomerase.
• yes the conclusions are supported by updated references
• no, the limitations of the study are not fatal and the researchers do describe how the limitations affected the results, and how these limitations could be altered in future studies on the topic.