Thanks for the question.
While Confession may have a therapeutic effect, a priest is not a therapist and therefore does not operate under the same guidelines.
That being said, prudence would dictate that such gifts could become inappropriate. Religious priests, those belonging to an order, who have taken vows of poverty, would already reject such gifts, but secular priests do not take such vows.
I imagine prudence would direct any gifts to the welfare of the parish or ministry of the priest and not to the individual so, while rules may vary, prudence is always warranted.