The empirical status of empirically supported psychotherapies: Assumptions, findings, and reporting in controlled clinical trials - summary of an article in Psychological bulletin

The empirical status of empirically supported psychotherapies: Assumptions, findings, and reporting in controlled clinical trials
Psychological Bulletin, 130

The assumptions underlying ESTs

ESTs are empirically supported therapies.

ESTs are typically designed for a single Axis I disorder, and patients are screened to maximize homogeneity of diagnosis and minimize co-occurring conditions that could increase variability of treatment response. Treatments are manualized and of brief and fixed duration to minimize within-group variability. Outcome assessment focuses primarily on the symptom that is the focus of the study.

RCT methodologies to validate ESTs require a set of additional assumptions that are neither well validated nor applicable to most disorders because: 1) psychopathology is highly malleable 2) most patients can be treated for a single problem or disorder 3) psychiatric disorders can be treated independently of personality factors 4) experimental methods provide a gold standard for identifying useful psychotherapeutic packages

Psychological processes are highly malleable

A substantial body of data shows that, with or without treatment, relapse rates for all but a handful of disorders are high. There is also a dose-response relationship. Longer treatments are more effective.

Most psychopathological vulnerabilities are highly resistant to change. They tend to be rooted in personality and temperament. The modal patient treated with brief treatments for most disorders relapses or seeks additional treatment.

Most patients have one primary problem or can be treated as if they do

In RCTs, including patients with substantial comorbidities would vastly increase the sample size necessary to detect treatment differences if comorbidity bears any systematic relation to outcome.

Three issues are: 1) The empirical and pragmatic limits imposed by reliance on DSM diagnoses 2) The problem of comorbidity 3) the way the different functions of assessing comorbidity in controlled trials and clinical practice may place limits on generalizability

The pragmatics of DSM-IV diagnosis

Three costs of the DSM are 1) the diagnoses are themselves created by committee consensus on the basis of the available evidence rather than by strictly empirical methods 2) The assumption that patients typically present with symptoms of a specific Axis I diagnosis and identify at the start of treatment precisely which one it is, is not generally valid 3) The number of disorders in the DSM renders the notion of clinicians learning disorder-specific manuals for more than a handful of disorders unrealistic

The problem of comorbidity

The questions is whether patients in clinical practice typically present with one primary disorder. Single-disorder presentations are the exception rather than the rule.

The methodology underlying the identification of ESTs implicitly commits to a model of comorbidity that comorbidity is random or additive.

The function of comorbidity assessment and generalizability to everyday clinical practice

The function of assessing for co-occurring conditions differs in research and practice in a way that can affect the generalizability of ESTs. The function of assessing comorbid conditions in the laboratory is to eliminate patients who do not meet study criteria. In clinical practice, clinicians do not assume that one symptom or syndrome is primary.

Psychological symptoms can be understood and treated in isolation from personality dispositions  

In ESTs the assumption that psychological symptoms can be understood and treated in isolation from the personality of the person is essential. No treatment in RCT is intended to change enduring personality processes. This has two complications 1) most Axis I syndromes are not independent of personality, and personality often moderates treatment response 2) including patients who share a diagnosis vary considerably in personality would require enormous sample sizes

The paradox of pure samples

If researchers include patients with substantial personality pathology in clinical trials, they run the risk of ambiguous conclusions if these variables moderate outcome. If one excludes these patients, one cannot assume generalizability.

Controlled trial provide the gold standard for assessing therapeutic efficacy

The functions of manualization

A key component of the assumption that experimental methods provide a gold standard for establishing ESTs is the assumption that the elements of efficacious treatment can be spelled out in manualized form. The aim of manualization is standardization of the intervention across participants and the control of potential confounding variables.

The logic of manualization

Manualizaiton is essential to 1) minimize variability within experimental conditions 2) insure standardization across sites 3) allow consumers of research to know what is being tested.

One cannot test experimental manipulations one cannot operationalize. It requires a very particular form and use of manualization.

This has two implications 1) the extent to which a treatment requires a competent clinical decision maker who must decide who and where to intervene on the basis of principles is the extent to which that treatment will not be able to come under experimental control in the laboratory This makes manuals really explicit and deviating from it makes the intervention different form the one that has been tested. 2) The scientific utility of treatment manuals is maximized in treatments in which the therapist sets the agenda for each session.

Empirical data on manualizaton

Therapist adherence to manuals has proven only variably associated with outcome.

Dismantling and the scientific testing of treatment packages

The assumption that the elements of efficacious treatment are dissociable and hence subject to dismantling is likely applicable to varying degrees of different treatments and disorders. It is invalid as a general rule of EST methodology. You’d have to test for infinite variables.

Science and prescience: selection of treatments to test as a source of bias

A significant caveat is the problem of determining which treatments to test. Treatments that cannot be tested using a particular set of methods cannot be supported using those methods.

Can hypothesis testing be isolated from hypothesis generation?

The influence of prescientific processes can lead to scientifically invalid conclusions despite the safeguards of scientific method imposed at the level of hypothesis testing.

In ESTs, empirically minded clinicians are placed in the position of having to guess, without data, how their own ways of intervening might fare relative to laboratory-based treatments. (TAU). TAU groups virtually all consists of low budget, low-frequency treatments.

Empirically unvalidated and empirically invalidated

Empirically unvalidated is untested. Empirically invalidated is empirically disconfirmed.

Incompatibilities between the requisites of experimental design and practice

The requisites of experimental research aimed at identifying ESTs can diverge form the requisites of good treatment.