Psychology is a relatively young science (the first scientific laboratory of psychology would not be created until 1879) and that evolves continuously, having emerged different schools of thought dedicated to different fields and conceptualizations of the human psyche. One of the best known and most popular fields is clinical psychology and psychotherapy, which helps to a great extent in the improvement of those patients suffering from different ailments, difficulties and disorders.

However, treating a patient is not the first thing that comes to mind: it requires the use of different techniques that have been shown to have real and significant effectiveness. Assessing the effectiveness of a technique requires evaluating not only the possible improvement of a patient but also comparing it with the absence of therapy and with other treatments and currents. The research carried out in this sense has generated great repercussions and ways of understanding psychotherapy and its effects. Even today there is debate as to whether or not the different types of therapy present significant differences in terms of effectiveness, something with a curious name: the Dodo effect, related to a subject known as the Dodo verdict . These two concepts will be discussed here.

What is the Dodo effect?

A hypothetical phenomenon called the Dodo effect reflects the fact that the effectiveness of all psychotherapy techniques is almost equivalent , with no significant differences between the multiple theoretical and methodological approaches available. The verdict of the Dodo is the subject of debate that revolves around the existence or non-existence of this effect. Do the therapies work because of their effectiveness in triggering the precise psychological mechanisms according to the theoretical model that is being used, or do they simply work because of other things that all therapists apply without realising?

Its name is a metaphor introduced by Rosenzweig in reference to Lewis Carrol’s book, Alice in Wonderland . One of the characters in this story is the bird Dodo, who considered at the end of the race without end the fact that “everyone has won and everyone must have prizes”. The effect in question was suggested by this author in a publication in 1936, considering after some research that it is the shared factors between the different perspectives and the functioning of the therapy that really generates a change and allows the patient to recover.

If this effect really exists, the implications could be highly relevant for the application of practical clinical psychology : the development of different therapies between the different currents of thought would become unnecessary and it would be advisable to investigate and generate strategies that focus on explaining and enhancing the elements they have in common (something that in reality is already done in practice, technical eclecticism being quite common in the profession).

However, different research has questioned and denied its existence, noting that certain approaches work better in certain types of disorders and populations.

Two opposing poles: the verdict of the Dodo

The initial research that seemed to reflect the existence of the Dodo effect was strongly opposed by various professionals , who conducted their own research and found that significant differences do exist. However, these investigations were later refuted by other authors, and we still find different research suggesting different conclusions.

Thus, we can find that there are mainly two sides to the question of whether there are statistically significant differences in the effectiveness of different therapies.

The importance of the therapeutic relationship

On the one hand, those who defend the existence of the Dodo effect affirm that almost all therapies have a similar effectiveness among themselves , not being so much the specific techniques of each theoretical current but the common elements underlying all of them that generate a real effect on patients. The latter defend the need to investigate and reinforce these common elements.

Some authors like Lambert defend that recovery is due to non-specific effects: partly to factors in the therapeutic relationship, personal factors of the subject outside the therapy itself, the expectation of recovery and of working for improvement and, only in a much more modest way, to elements derived from the theoretical or technical model itself.

The truth is that different research has emerged that supports the great importance of these aspects, some of the main ones being the therapeutic relationship between professional and patient (something that has been given great importance from all disciplines) and the attitude of the therapist towards the patient and his or her problems (empathy, active listening and unconditional acceptance among them). But this does not necessarily exclude the possibility that (as proposed by Lambert), there are differences between treatments when it comes to their effectiveness.

The importance of the therapy model

Those who defend that significant differences do exist between therapies, on the other hand, observe real differences in the effectiveness of the treatments and value that the basic functioning of the different intervention strategies employed is what generates the behavioural and cognitive change in the patient, with some strategies being more effective than others in certain disorders or alterations.

The different investigations carried out comparing treatments have shown different levels of effectiveness depending on the problem to be treated and the circumstances surrounding it.

It has also been observed that certain therapies can even be counterproductive depending on the disorder in which they are applied, something that has had to be controlled in order for patients to improve and not the opposite. This would not be the case if all therapies worked the same way. However, it is also true that this does not prevent the core of the change from being due to common factors among the different therapies.

What about an intermediate consideration?

The truth is that the debate is still going on today, and there is no clear consensus on this, and research is going on as to whether the effect or verdict of the Dodo is really there or not. In both cases, different methodological aspects have been criticized that may cast doubt on the results obtained or have implications different from those initially considered.

Probably neither of the two sides can be considered absolutely right, there being procedures that are more appropriate than others in certain situations and subjects (after all, each subject and problem has its own ways of working and its modification requires more focused action in certain areas) but the elements shared between the different therapies are the main mechanism that allows the generation of change.

In any case, it should not be forgotten that the clinical practice of psychotherapy is or should always be done for the benefit of the patient , who is the one who comes to the consultation seeking professional help from a person prepared for this. And this implies both knowing specific techniques that have been shown to be effective and developing and optimizing basic therapeutic skills so that a context can be maintained that is, per se, beneficial for the patient.

Bibliographic references

  • Lambert, M.J. (1992). Implications of outcome research for psychotherapy integration. In Norcross JC and Goldfried MC (Eds.). Handbook of psychotherapy integration (pp.94-129). New York: Basic Books.
  • Fernández, J.R. and Pérez, M. (2001). Separating the grain from the straw in psychological treatments. Psicothema Vol. 13(3), 337-344.
  • González-Blanch, C. and Carral-Fernández, L. (2017). Cage Dodo, please! The story that all psychotherapies are equally effective. Papers of the Psychologist, 38 (2): 94-106.