Be honest about your motivation to discontinue use, If you don't want to stop, it will be harder to stop. Be sure to use counseling to help with emotional or cognitive aspects. For this they are better than benzodiazepines especially when there is a suicide risk. As a general rule, insomniacs with major depression should be told to take the entire dosage of antidepressant at bedtime in order to maximize the sedative effects. Antidepressants have a lower potential for abuse or dependency but higher drug interaction than with benzodiazepines.
Antidepressants suppress REM in people with major depression.
There is some research that shows that suppressing REM in people suffering major depression is a help, that for some reason they are getting too much REM sleep and so benefit from the lesser amounts they get when taking these drugs. The side-effect is drowsiness, so people use them to promote sleep at night. There appears to be little actual beneficial effects on sleep. There has been very little research attention, and their effect beyond placebo is doubtful.