Are his mood cyclical, does he alternate from depression to an upper, hype type mood, not needing as much sleep, starting many projects, being able to work for as long time, and maybe spending too much. The reason I ask is that there is an overlap between AAHD and being BiPolar. Your mention of depression brings up one half of the equation, manic behavior being the other half along with a cyclical pattern.
One of the problems with antidepressant is that they often take several weeks for them to start working. The brain resists the change the pills want to make, then accepts the new neurotransmitter levels and the depression starts to lift. That is, if the pills work at all. not all people react well to antidepressants.
Also, are you able to accept the fact that your husband most likely has a biological problem, would it make a difference if he had MS, for instance. If so, then you probably should educate yourself to the biological nature of your husband's problem. His problem might affect his behavior, but both still have the same biological basis as the root of the disease. And while behavior often seems intentional and willful, it is not always so, especially when these diseases come into play.
Does his family have any history of these types of depression and ADDHD behavior. If so, your husband might be in need of serious medical, psychiatric attention, and, if so, counseling won't help him.