Psychology 3301F/G Chapter Notes - Chapter 12: Randomized Controlled Trial, Psychodynamic Psychotherapy, Hans Eysenck
27 Apr 2018
School
Department
Course
Professor
Psych 3301 Chapter 12
• In 1952 Hans Eysenck published an article in which he argues that rates of
improvement among clients receiving psychodynamic or eclectic therapy
were comparable to or worse than rates of remission for untreated clients
• At that time there were no randomized control trials clinicians just claimed
the efficacy based on clinical experience and case histories
Randomized controlled trial: an experiment in which research participants are
randomly assigned to 1 of 2 or more treatment conditions
• From the 1950’s to the early 1970s a number of competing reviews were
published
• The publication of the first meta-analysis of the psychotherapy literature by
Mary Smith and Gene Glass (1977) was a landmark in efforts to review
scientific literature on treatment outcome
Effect size: a standardized metric typically expressed in standard deviation units or
correlations that allows the results of research studies to be combined and analyzed
• In standard deviation units a between groups effect size of d=.5 means there
is a difference of one-half standard deviation between treated and control
groups
• When correlational analyses are used the effect size is expressed as an r
statistic
• Smith and Glass reported the average effect of psychotherapy to be d=0.68
meaning the average person receiving treatment was better off at the end of
treatment than 74% of those who had not received treatment
• When Smith and col calculated efficacy of various types of treatment they
found the largest effect sizes for cognitive (1.31) and cognitive-behavioral
(1.24) treatments followed by behavioral (.91), psychodynamic (0.78) and
humanistic (.63)
• Some of the largest effect sizes were for anxiety and mood problems
Criticisms of meta-analyses: a) garbage in garbage out-if poor quality studies are
included they could negatively influence the results b) apples and oranges
argument-concerns over meaningfulness of including different treatments and
different measures in a meta-analysis
• In 1980s and 1990s number of meta-analyses grew and began to look at
what treatments were efficacious for what disorders etc.
• Use of meta-analysis to review research now gold standard
Table 12.1 P.433
Publication bias: tendency for journals to selectively publish research that has
statistically significant results
Drew Westen and co examined how a number of methodological issues affected the
results of treatment research by analyzing a number of other treatment-related
variables in addition to treatment outcome (recovery rates, number of patients
excluded, persistence of treatment benefits) to determine a) the clinical significance
of obtained treatment results and b) the applicability of the research results to the
general population
• Severity of symptoms reported in RCTs is greater than that found in patients
seeking routine psychotherapy
Implications of this are: a) there are likely to be efficacious treatment options for
most patients even those with comorbid diagnoses b) in working with patients with
comorbid diagnoses psychologists must decide which diagnosis should be address
first
Clinical practice guidelines: a summary of scientific research dealing with the
diagnosis assessment and/or treatment of a disorder designed to provide guidance
to clinicians providing service to patients with the disorder
• First initiative in developing clinical practice guidelines in clinical psychology
was in the early 1990’s by the APA society who created a task force headed
by Dianne Chambless to set a standard for defining treatment efficacy
For a treatment for be designated as empirically supported by the task force it
required: evidence of symptom reduction and/or improved functioning either from
at least 2 independently conducted RCTs or from a large series of single-case studies
Empirically supported treatment: a psychotherapy that has been found in a series of
randomized controlled trials or single-participant designs to be efficacious in the
treatment of a specific condition
• Critics of the EST initiative expressed concerns about issues ranging from
scientific soundness to potential negative impacts on practicing clinicians
• Important difference between statistically significant differences and
clinically significant differences
Chambless and Holllon’s (1998) criteria for empirically supported treatments→
Methodological and statistical criteria for treatment studies:
1. Comparison of treatment with a no-treatment control group, alternative
treatment group or placebo in an RCT
2. Treatment must be statistically significantly superior to the comparison
groups or equivalent to another treatment with established efficacy
3. Research must have sufficient statistical power to detect moderate
differences
4. Research must have been conducted with a) a treatment manual or its
equivalent b) a population treated for specified problems c) reliable and
valid treatment outcome measures that assess the problems addressed in
treatment d) appropriate data analysis
Designation criteria for treatments:
• Efficacious: superiority of EST must have been shown in at least 2
independent research settings
• Possibly efficacious: one study is sufficient in absence of conflicting evidence
• Efficacious and specific: EST must have shown to be statistically significantly
superior to a pill, placebo, or alternative treatment in at least 2 independent
research settings
-health care professional should consider a treatment with existing research
support before turning to untested treatments
Approach developed in the UK used 3 criteria to determine whether there is
evidence of treatment efficacy: 1) must be a minimum of a single high-quality RCT
