what are the major classes of antidepressants

Alternative Medicine
#1
#2

Selective serotonin reuptake inhibitors (SSRIs)
Serotonin-norepinephrine reuptake inhibitors (SNRIs)

#3

Tricyclic antidepressants (TCAs)

#4

Monoamine oxidase inhibitors (MAOIs)
Atypical agents.