Lecture 3 - Methods in Psychotherapy Flashcards
Research on Psychotherapy
➢With increase in types of psychotherapy, framework to evaluate psychotherapy developed
➢Methods:
Case studies… study a specific patient
Naturalistic studies… compare patients with old vs new (before vs after) form of psychotherapy treatment
Quasi-experiments… compare 2 different types of psychotherapy but not randomly assigned
Randomized controlled trials (RCTs)
Adopted from medicine
Experimental design = cause and effect3
Compare treatment with control (ex: placebo)
Randomized Controlled Trial: Steps
➢Step 1: Develop the protocol
➢Step 2: Choose comparison to treatment of interest
➢Step 3: Select participants of interest
➢Step 4: Randomly assign participants to conditions
➢Step 5: Administer treatment and assess fidelity
➢Step 6: Evaluate outcomes at end of treatment (evaluate treatment)
➢Step 7: Evaluate outcomes at follow-up time points (follow-up)
➢Step 1: Develop the protocol
➢What is the treatment?Theoretical model:
May come from arm-chair theorizing, clinical observation, basic psychological research
Treatment techniques:
What will you do in therapy to change problems specified in theoretical model?
➢How will the treatment be administered?
Needs to be standardized:
Development of treatment manuals
Training and supervision of clinicians
➢Step 2: Choose comparison to treatment of interest
➢To what will you compare the treatment of interest?
Waitlist control:
Not equivalent to placebo in pharmacotherapy trials
Eventually administer treatment for ethical reasons
Supportive psychotherapy:
Control for interaction with therapist and common factors
Gold standard treatment:
CBT is often gold standard to which new treatments are compared
➢Step 3: Select participants of interest
➢Who will your participants be?
Balance concerns with internal versus external validity:
Internal validity: quality of experimental design and control for extraneous factors
External validity: will results extend to other people and settings
Ideally, want participants to be representative of population of persons to which results will be generalized:
Demographic factors (all genders? All races and ethnicities?)
Comorbid diagnoses (can increase internal validity if excluded, but decreases external validity (doesn’t represent people in the real world as comorbidity is the norm))
➢Step 4: Randomly assign participants to conditions
➢Assess baseline characteristics of participants
➢Random assignment minimizes pre-existing differences between groups that could affect outcome
e.g., gender, race, baseline levels of depression
➢Blinding
Single-blind (participant doesn’t know what condition they’re in) versus double-blind (both participant and clinician doesn’t know what condition px is in)
Double-blind not possible in psychotherapy trial (clinician knows which participant is receiving psychotherapy treatment)
➢Step 5: Administer treatment and assess fidelity
➢Are the therapists administering the treatment as outlined?
Fidelity checks (ongoing supervision of the therapist, recording of the sessions, coding of the sessions)… ensure they are doing what they’re supposed to
➢How well is the treatment being administered?
Therapist factors
➢Step 6: Evaluate outcomes at end of treatment
(12 sessions typical length of a CBT treatment)
➢What is the outcome of interest?
No longer meeting DSM diagnostic criteria (but is it always a meaningful change? Could go from 5 to 4 symptoms and technically no longer meet diagnostic but…)
A decrease in target symptoms
By how much?
A decrease in comorbid symptoms
e.g., decrease in anxiety in treatment for depression
An increase in functioning
Occupational, social
➢Statistical significance
p< .05; 5% likelihood that result occurred by chance
Magnitude of effect AND sample size influence statistical significance
➢Effect size
Magnitude of difference, independent of sample size!!
Formula: Mean difference between experimental and control group/standard deviation of control group
Cohen’s d: 0.2 = small; 0.5 = medium; 0.8 = large
How much change is needed for clinical significance
-often want to move from 1 sd of the average of a clinical group to 1sd of the average of a non-clinical group… but depends
➢Therapist and site effects
Random factors unrelated to treatment must be accounted for
➢What about people who drop-out?
Intention-to-treat analyses (don’t just ignore the people who dropped out)
➢Step 7: Evaluate outcomes at follow-up time points (follow-up)
➢What happens after treatment is withdrawn?
Relapse
Sleeper effect (not much happens during, but continues to get better after treatment)… think of sleeper build
➢Psychological treatment more enduring than medication(DeRubeis, Siegle, & Hollon, 2008)13
-equally well in short term, but CBT maintains better long-term
Reporting RCT Results
-Consort flow diagram
-required in any RCT paper
-helps see flow of how the treatment went
2024-09-0515Meta-analysis
➢What does the body of research say about psychotherapy or a particular treatment?
Statistical technique to pool effect size estimates (useful because independent of sample size)
-Taking all the effect sizes of a bunch of studies
Can examine moderators of treatment efficacy
Are the effects larger in a particular group of participants? When using particular outcome measures? For specific practitioners?
First meta-analysis of psychotherapy: Smith and Glass (1977)
-Meta-analysis of 375 controlled therapy studies
-Typical therapy client better than 75% of untreated clients
-Combined effect size = 0.68
-Effects sizes similar across different treatments16
Empirically supported treatment (EST)
Definition of an EST➢Chambless & Hollon(1998); Journal of Consulting and Clinical Psychology
Well-established treatments
At least two “good” between-group design experiments that show the treatment is better to a medication, psychotherapy placebo, or other treatment OR is equivalent to an established treatment OR
A large series of single-case design experiments with good experimental design and comparison to another treatment AND
Must be conducted with treatment manuals or other clear description
Characteristics of samples must be clearly defined
Effects must be demonstrated by at least two different investigators or teams
Probably efficacious treatments
Two experiments show treatment is better to waitlist control OR
One or more experiments meet criteria above but have not been replicated by independent investigators OR
A small series of single case design experiments have been conducted
➢Tolin et al. (2015); Clinical Psychology: Science and Practice
Evaluation based on two studies is unreasonably low bar given # of RCTs
Focus on systematic reviews and meta-analyses
Consider quality and risk of bias of individual studies and systematic review
Focus has been on symptom reduction
Measure functional impairment and quality of life –what is most relevant to patient
No guidance on which EST to choose from list
Include information on strength of treatment
Evaluate clinical AND statistical significance
