What's the difference between ssri antidepressants and tricyclic antidepressants?

SSRI R newer: With less side effect.

SSRI's vs Tricyclics: The ssri's focus on blocking serotonin reuptake, and the tricyclics are non-selective in their receptor activity. Histamine blockade and others in tca's causes more sedation; there can also be postural hypotension with tca's. Ssri's may be safer in overdose, less likely to cause arrhythmia -- could be important in patients w/heart disease. Ssri's have their own side effect profile though.