I appreciate the opportunity to review this manuscript as it is an important contribution to the field of cognition research, as it fills a gap regarding longitudinal research and offers a promising way to address long-term associations between MetS and cognitive function in individuals with BD. The use of a longitudinal study is a relatively novel , but very important approach in this area and allows for a deeper and more thorough examination of the association of Mets and cognition. However, the relatively short observation period of only two years limits the capacity to detect long-term cognitive changes and may have contributed to the lack of significant findings. While this limitation is acknowledged appropriately by the authors, it should be emphasized that longer follow-up periods would be more suitable to capture potential delayed effects of MetS on cognition.
The manuscript is well-structured and accessible and the study design and procedures are described in sufficient detail to allow replication by other researchers. I particularly appreciate that the authors precisely defined inclusion and exclusion criteria concerning euthymic mood states and the presence of MetS.
Areas for Improvement:
- Loss to follow-up (over 50%) is a major concern. maybe the authors could use LMM to handle repeated measures and varying covariates over time.
- The literature cited in the Introduction is somewhat dated. It would strengthen the paper to include more recent studies and findings to reflect the current state of research in this area.
- The data and materials underlying the study are not publicly available due to the involvement of clinical participants. While it is understandable that access must be restricted, I recommend emphasizing transparency by outlining clear steps for data access and considering ways to provide anonymized data if possible.
- While conservative, Bonferroni correction may be overly stringent in neurocognitive studies where variables are intercorrelated. The authors could consider using false discovery rate for their analyses.

Minor Points:
o In the reference list, the citation for Vancampfort et al. is missing the publication year.
o There are several typographical and minor formatting errors throughout the manuscript that should be corrected.
o It should be discussed whether including only participants who completed the neuropsychological assessments at baseline in the longitudinal analyses might introduce a selection bias.
o The cognitive test battery is well thought out and covers all major cognitive domains; however, it would be helpful to include references for each test used.
o It would be of interest to readers to know the total number of patients included in the database, even if only a subset was analyzed longitudinally.
- maybe add more clinical implications in the discussion, that would be interesting.