Hi, I'd like to help you with your question.
It sounds as if your wife may have another diagnosis in addition to her depression. I agree with you, from what you described regarding your wife's behavior, it sounds as if she might have Intermittent Explosive Disorder or another impulse control issue.
However, it depends on whether or not this is a new behavior for her or not. If it is new, there could a biological cause. Was your wife's behavior normal during her earlier years? If so, there could be a frontal lobe problem or another physical cause.
If she has not done so, I highly recommend that your wife see her regular doctor for a brain scan to be sure there was not a physical cause for her rages and other behaviors. Often, as a person ages, there can be mini stokes or other brain issues that cause changes in behavior. This needs explored first, just to rule out the physical cause.
If your wife is cleared physically, try asking her doctor about an Impulse Control disorder. Although rare in women, she could possibly have this problem. That would change her treatment to include focus on the behavior problems she is having. Here is an excellent link to help you- http://psychcentral.com/lib/2007/what-are-impulse-control-disorders/. It will give you a better idea if she has the symptoms or not.
Your wife could also be dealing with a personality disorder. Although I don't believe from what you said that she has one, it is a possibility. Her psychiatrist or therapist can explore this to see if she fits a diagnosis. I highly doubt they would have missed it, but because she can be manipulative, she could have hidden the symptoms.
There are also a few books that may give you ideas on how to deal with the stress of dealing with your wife's behavior. One is called When Someone You Love Has a Mental Illness by Rebecca Woolis. Another is The Burden of Sympathy: How Families Cope With Mental Illness by David A. Karp. You can find these on Amazon.com or your local library may have them available.
I hope this has helped you,