In my last contract my supervisors were great but the team was a lot like you are describing...isolating, talking behind my back, shaming and passive aggressive. It was the same team. I couldn't get any peer training and therefore hardly any tasks. It definitely affected my depression although I kept trying to dismiss it.

I realize the economy is bad and the job itself makes it hard but it really would be in your best interest to look. Sometimes the mere act of looking can make you feel better in your current job. In addition, if they are jerks, you don't have to use them as a reference. You can avoid having to ask and not knowing if they will be vindictive. Work is such a time consuming and temporary state. I think having a less hostile work place is incredibly important.