Suggest Treatment For Agitation, Tremors, Disheartened Feeling While Treating Depression

My wife has suffered from depression over varying periods of time and has most recently experienced difficulty for a number of months. She has been taking Effexor for a few months, with dosages increased a few times, recently (10 days ago), to 300 mgs. Her symptoms have worsened within the last few days, e.g., agitation, shakiness, and loss of spirit. This dosage appears high -- your thoughts?