This is what my psychiatrist to me:

Depression involves two problems: sadness and lethargy. A person can have suicidal thoughts, but lethargy will sometimes stop them from committing suicide. There's a danger that an antidepressant will eliminate the lethargy without eliminating suicidal thoughts. So when a patient starts on an antidepressant, he or she must be closely monitored.

By the way, it's probably better to get antidepressants from a psychiatrist rather than an internist.

If your psychiatrist actually believes that sadness and lethargy are the only two effects of depression, then you need to go to a good internist or general practitioner who can explain the chemical imbalances involved and the chemistry of the antidepressants that help to change them.

Depression causes such symptoms as anger, stomach ailments, headaches, risk-taking behavior and many other symptoms. It can manifest in many, many different ways. His simplistic description is dangerously incomplete.

What your doctor told you is fiction. Either he thinks you aren't bright enough to understand a proper explanation or he is completely clueless about how the drugs he prescribes actually work.