No.  In most instances, psychological counselling is not subject to GST.  If, however, your counselling is being paid for by your employer, or is work related (such as when you intend to claim it as a work related tax deduction) then GST will need to be added, but only if your therapist is registered for GST.  If your counselling is work related or being paid for by your employer, please advise your therapist when making an appointment so they can determine if GST will apply.