I say these things from experience as I am a spouse of a bullied target and have first-hand experience of the above. When partners are suffering from depression or reactive depression it is very hard for them to complain to their superiors that they are getting bullied at work. Bullying sucks the energy from you and that is why you will notice your partner will be so tired. When this happens this is when you, the spouse, has to make sure that your partner's illness does not deteriorate any further. If reactive depression is the diagnosis it is easier explained as a reaction to a situation your partner has been forced to cope with.
Reactive depression can last for months.
In severe cases it can last for years. This situation has to be removed before any improvement can be made. This is easier said than done. Bullies are not likely to admit to the fact they are bullies. Exposure is what they hate.