Association between Single Nucleotide Polymorphisms in Monoamine Oxidase and the Severity of Addiction to Betel Quid
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsIn this Brief Report, the Authors investigated the different characteristics of betel-quid (BQ) use disorder (BUD) patients based on three different types of severity of addiction according to clinical interview, psychometric questionnaires and emotional rating scales. In order to study possible association between addiction severity of BUD and single nucleotide polymorphisms (SNPs) of candidate genes they analyzed the SNPs selected based on the previous experiences from the different genetic association studies about the oral cancers and addiction. The results, presented in Tables 1, 2, 3 and 4 are very clarifying and demonstrate more severe symptoms of BUD were presented with younger age of using BQ, poorer oral hygiene, more severe craving and more anxious mood for BQ use. In addition, the Authors found that different alleles of MAOA rs5953210 were possibly associated with the addictive severity of BQ.
The approach is correct, the methods used are also correct, the results are clearly expressed in the text and mostly well demonstrated in the tables and the discussion and conclusions are appropriate according to the results obtained.
Although I don't have any major criticisms, smaller shortcomings require correction:
1. When discussing the mechanism of the neurochemical action of BQ, the authors only mention the interaction with MAO but the BQ action is broader. It should be added that arecal alkaloids act as competitive inhibitors of GABA receptors [e.g., Boucher BJ, Mannan N. Metabolic effects of the consumption of Areca catechu. Addict Biol. 2002 Jan;7(1):103-10. doi: 10.1080/13556210120091464.]. Also, other neurotransmitter systems are affected in the consequence of BQ use. [e.g., please see, Stokes C, Pino JA, Hagan DW, Torres GE, Phelps EA, Horenstein NA, Papke RL. Betel quid: New insights into an ancient addiction. Addict Biol. 2022 Sep;27(5):e13223. doi: 10.1111/adb.13223.]
2. A serious problem exists with Table 5 which is unreadable because it may have been incorrectly inserted into the text. One can only guess what is presented there.
Comments on the Quality of English Language
Some typographical errors need correction.
Author Response
Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions.
For question 1, we've inserted the references about GABA, nicotinic acetylcholine, and another paper about dopamine interaction about areca nut in line 49-51.
For the question 2, we've sent for English Editing for better elaboration of the English grammar and sentences.
Reviewer 2 Report
Comments and Suggestions for AuthorsThis brief report investigates the association between 6 SNPs (BRCA1, COL9A1, NOTCH1, HSPA13, FAT1, and MAOA) and the severity of betel-quid (BQ) use disorder (BUD) among 50 patients recruited from a cancer center in China. Severity of BUD was defined according to DSM-5 criteria for severe SUD. Comparisons were also made for a self-reported severity scale for BQ (SUSRS-BQ), the Yales-Brown Compulsive Scale-betel-quid for craving severity, and several self-report scale for depression. The primary result is that cases of severe BUD, compared to non-severe BUD, were 7.9 times more likely to have the MAOA rs5953210 GG polymorphism. In addition, the severe SUD group scored higher on the SUSRS-BQ, used more BQ, scored higher on craving and anxiety, and was more likely to have the CC form of BRCA1. The groups did not differ on depression.
Strengths include the following:
1. Betel-quid use is highly prevalent in many regions of the world, including Asian countries, where the study was conducted.
2. The OR for MAOA is strong despite the small sample size.
Weaknesses:
1. The writing is often unclear and there are numerous spelling errors. The manuscript could benefit from editing for English.
2. The definition of severe SUD is unclear. The abstract reads “less or more than 6.” I think this should read “6 or more symptoms.”
3. The justification for a specific focus on these SNPs on addiction is weak. Some justification appears in the Discussion, which may be better moved to the Introduction. More specifically, the most compelling premise for the study appears on lines 296-297. Framing the Introduction around this idea might improve the paper.
4. Table 5 is cut off on the left margin.
5. The analyses appear to be bivariate, without statistical controls. For example, although Table 4 is organized as if it were presenting results from a logistic regression model, this does not seem to be the case. Rather, the ORs presented are bivariate associations between each of the 4 variables and SUD severity. This also appears to be the case for Table 5, which does not account for the significant variables in Table 4. As a result, it is unclear how to interpret the findings from other potential confounders and covariates.
6. Table 5 shows that SUD is associated with BRCA1. However, the paper does not discuss this finding.
7. The study is silent on the potential confounding of MAOA and antisocial disorder, which has been strongly linked with both MAOA and SUD (of various kinds, not sure about BQ).
8. The Conclusion states (lines 308-309) that “In addition, MAOA rs5953210 AA was noted in severe BUD patients.” However, Table 5 suggests that the BB form was more common in severe cases.
9. This Reviewer is not convinced that the genetic finding here constitutes a biomarker for BQ SUD, as the manuscript seems to imply. Rather, the more interesting finding may be that the link between heavy BQ use and cancers may have a common underlying genetic foundation.
10. The title includes the term “influence,” which inappropriately implies a causal link.
Comments on the Quality of English Language1. The writing is often unclear and there are numerous spelling errors. The manuscript could benefit from editing for English.
Author Response
Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections to the weakness suggested from the reviewer 2.
For the weakness below:
1.The writing is often unclear and there are numerous spelling errors. The manuscript could benefit from editing for English.
Response: We've sent for English Editing.
2.The definition of severe SUD is unclear. The abstract reads “less or more than 6.” I think this should read “6 or more symptoms.”
Response: Thanks a lot for the advice and we revised this point in line 23.
3.The justification for a specific focus on these SNPs on addiction is weak. Some justification appears in the Discussion, which may be better moved to the Introduction. More specifically, the most compelling premise for the study appears on lines 296-297. Framing the Introduction around this idea might improve the paper.
Response: We've elaborated the point and added previous studies about MAOA related to heavy BQ use in the Introduction part in line 77-78.
4. Table 5 is cut off on the left margin.
Response: All tables were corrected again to be suitable for the manuscript. For the poor illustration and out of margin of tables, we made revisions and corrected again the results of statistics of tables 1 in line 200, table 2 in line 220, table 3 in line 241, table 4 in line 248, and table 5 in line 274.
5.The analyses appear to be bivariate, without statistical controls. For example, although Table 4 is organized as if it were presenting results from a logistic regression model, this does not seem to be the case. Rather, the ORs presented are bivariate associations between each of the 4 variables and SUD severity. This also appears to be the case for Table 5, which does not account for the significant variables in Table 4. As a result, it is unclear how to interpret the findings from other potential confounders and covariates.
Response: Thank you for your comment. We apologized that we did not describe the statistical methods clearly. We have described a logistic regression model in statistical analysis as follows. Because there were no normal controls in the study, we combined mild BUD and moderate BUD into nonsevere BUD as statistical controls. We used the logistic regression analysis model to analyze emotional assessment and association between SNPs and severity in addictiveness of BUD, based on severe BUD and nonsevere BUD patients. We made the gap for the above weakness and the reasonably statistical illustrations were added in line 178-180 , line 181-183, and line 232-234.
6. Table 5 shows that SUD is associated with BRCA1. However, the paper does not discuss this finding.
Response: Thanks a lot for the recommendation. We discussed about BRCA1 rs2070833 in line 290-291. We also discussed about the possibly overlapping role in risk of cancer and addiction about SNPs BRCA1 and MAOA in line 315-316.
7. The study is silent on the potential confounding of MAOA and antisocial disorder, which has been strongly linked with both MAOA and SUD (of various kinds, not sure about BQ).
Response: Thanks a lot for the reminding that confounders are possible with antisocial disorder and MAOA. In the method part, the semi-structured interview was carried out by Mini-International Neuropsychiatric Interview (M.I.N.I.) and the patient with antisocial personality disorder was also excluded out in this study. The corrections and exclusions were listed in line 108 and line 113-114.
8. The Conclusion states (lines 308-309) that “In addition, MAOA rs5953210 AA was noted in severe BUD patients.” However, Table 5 suggests that the BB form was more common in severe cases.
Response: We corrected these inconsistent discussions about the association with addiction severity of MAOA rs5953210 and more prevalent GG alleles in line 293 and line 329.
9. This Reviewer is not convinced that the genetic finding here constitutes a biomarker for BQ SUD, as the manuscript seems to imply. Rather, the more interesting finding may be that the link between heavy BQ use and cancers may have a common underlying genetic foundation.
Response: Thanks a lot for the opinions, and we modified the sentences about the possible link between heavy BQ use, addictive property and cancers related to preliminary genetic association study. Further investigation for possibility of design of potential biomarker of BQ SUD may need more participant numbers. We also made the statement about the possibly overlapping mechanisms of carcinogenic effects, heavy BQ use, possible addictiveness of BQ in line 315-316.
10. The title includes the term “influence,” which inappropriately implies a causal link.
Response: Thanks a lot for the comments, and the term ”influence” was replaced by “association” due to our study limitations. We changed the title to "Association of the Genetic Polymorphism of Monoamine Oxidase with Addiction Severity of Betel-Quid" in line 2.
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThe manuscript is improved and responsive to the critiques.
Comments on the Quality of English LanguageI detected one spelling error, but there could be more. The quality of English has vastly improved in this version, but language should be reviewed once more.
Author Response
Thanks again for your precious opinions and careful revisions. I’ve made again the revisions about the English words and sentences accordingly. The revised parts were as as shown below: 1. Betel-quid to Betel quid in the manuscript in line 16 and line 35. 2. We changed “into severe groups to "into the severe group" in line 22. 3. Monoamine oxidase inhibitor (MOAI) to Monoamine oxidase inhibitors (MAOIs) in line 43. 4. We changed "MAO-A inhibitor and selective serotonin reuptake inhibitor (SSRI)" to "MAO-A inhibitors and selective serotonin reuptake inhibitors (SSRIs)" in line 48. 5. We changed "possibly related to the development of salivary duct and intracapsular carcinomas" to "possibly related to the development of salivary duct and intracapsular carcinoma" in line 66. 6. We changed "gene interruption studies" to "studies of genetic interactions" in line 69-70. 7. We changed "alcohol and tabaco "alcohol and tobacco " in line 75. 8. We changed "the Department of general physicians" to "the Department of General Physician" in line 90. 9. We changed "Diagnosis of cancer and precancer" to "Diagnoses of cancer and pre-cancer" in line 114. 10. We changed "obtained data on the number of broken teeth" to "obtained data on the numbers of broken teeth" in line 125. 11. We changed the term of "Yale–Brown Obsessive Compulsive Disorder Rating Scale (YBOCOS-BQ)" to "Yale–Brown Obsessive Compulsive Disorder Rating Scale for betel quid (Y-BOCS-BQ)" in line 141, line 142, line 216, line 224, line 238, line 258, line 282,and line 287. 12. We changed "HAMDRS" to "HDRS" in line 148, line 150, line 230, line 236, line 243, line 244, line 245, line 256, and line 257. 13. We changed the sentence ” MAOA and those related to BQ-related carcinogenesis” to “MAOA and those being associated with BQ-related carcinogenesis” in line 155. 14. We changed "Beck Anxiety Index" to "Beck Anxiety Inventory" and "Beck Depression Index" to "Beck Depression Inventory" in line 245 and line 257. 15. We changed "The abovementioned data indicate that" to "The abovementioned data indicated that" in line 294. 16. We changed "MAO rs5953210" to "MAOA rs5953210" in line 311. 17. We changed "focused on lessening the harm from BQ" to "focused on reducing the harm from BQ" in line 320.