The first group sound like SSRI's which is the group Zoloft is in. They are pretty similar, although they may help more or less or have different side effects in different people. That's because everyone has an individual response. The second group has effexor which works on serotonin and norepinephrine. Remeron I took and gained a lot of weight. The third group sound like tricyclic antidepressants which are an older type. They cause more drowsiness and dry mouth side effects. Because of this they are usually used in smaller doses to help with sleep or pain, or to help other meds. Hope this helps. Most of the names are different than US, but are similar. HUGS!