An elderly house wife lost her husband who died suddenly of myocardial infarction couple of years ago. They had been staying alone for almost a decade with infrequent visits from her son and grandchildren. About a week after the death she heard the voice clearly talking to her as he would in a routine manner from the next room. She went to check but saw nothing. Subsequently she often heard his voice conversing with her and she would also discuss her daily matters with him. This however, provoked anxiety and sadness of mood when she would remain preoccupied with thoughts about him. She should be treated with: