One line of research consistently finds that supposedly different forms of psychotherapy show similar effectiveness. According to The Handbook of Counseling Psychology: "Meta-analyses of psychotherapy studies have consistently demonstrated that there are no substantial differences in outcomes among treatments". The handbook states that there is "little evidence to suggest that any one psychological therapy consistently outperforms any other for any specific psychological disorders. This is sometimes called the Dodo bird verdict after a scene/section in Alice in Wonderland where every competitor in a race was called a winner and is given prizes".