Altogether 326 patients of the Helsinki Psychotherapy Study , with anxiety or mood disorder , were randomly assigned to either short-term psychotherapy of about six months ( solution-focused therapy ( SFT , n = 97 ) or short-term psychodynamic psychotherapy ( SPP , n = 101 ) ) , or to long-term psychodynamic psychotherapy ( LPP , n = 128 ) , lasting on average three years .