Major depressive disorder

Please the research article uploaded to discuss   the following questions
Questions
1.    What should be the specific scope of the future studies in order to provide clear and sufficient evidence to confirm the existence of data-driven symptomatic depression subtypes?
2.    Are the studies foreseeable in the next decade?
3.    Were the inclusion criteria sufficient, reliable and credible enough so that out of the 1176 retrieved articles, only 20 were deemed satisfactory?
4.    Was this number adequate to meet the demands of credibility and inclusivity?