How Does CT Work? Predictors and Mechanisms of Change

Question 1

Mediation defintion

Answer 1

theoretical definition: the mediator is the intermediate in the causal path from a treatment to the outcome (mechanism of action - why the treatment works)
statistical defintion: mediation exists when c’ pathway is smaller than c pathway (i.e. the indirect relationship through the mediator explains a significant portion of the relationship b/w the predictor and outcome)

Question 2

Cognitive Mediation model of CT

Answer 2

CT – change in cognition (mediatior) – change in depression

Question 3

Mediation model: temporal order

Answer 3

mediation specifies a temporal order - change in cognition must occur after CT, then change in depression must occur after change in cognition

Question 4

Mediation model: evidence for “a” path

Answer 4

CBT leads to reduced negative cognition (fewer automatic thoughts and dysfunctional attitudes) BUT not any more than other therapies; mixed evidence for CBT vs meds

Question 5

Mediation model: Evidence for “b” path

Answer 5

-change in cognition and depression symptoms co-vary over CBT, but this is NOT evidence for mediation model because there is no temporal order present, and there may be a third variable

Question 6

Cognitive Mediation of CT: Quigley et al overview

Answer 6

-tested cognitive mediation in a trial of CBT over 16 weeks - depression symptoms and cognition measured every four weeks

Question 7

Cognitive Mediation of CT: Quigley et al hypotheses and results

Answer 7

Hypothesis 1: CBT would lead to greater change in the cognitive variables than meds
partially supported: symptom and cognitive change occurred earlier in meds group, but by end of treatment participants in CBT condition had lower levels of maladaptive cognition and depression symptoms

Hypothesis 2: the cognitive variables would predict depression symptoms at subsequent time points
unsupported: there were concurrent relationships between cognition and symptoms, but no longitudinal relationships were significant (so no mediated effect)

Hypothesis 3: there would be a significant indirect effect of treatment condition on depression symptoms via change in cognitive variables
unsupported: no significant effects on longitudinal indirect effects

Evidence for cog. mediation model?
Cross-sectionally yes, but not longitudinally - may be an issue with timing, not all individuals will show longitudinal change at same time

conclusions: no strong evidence for mediation model, but no evidence that it doesn’t work either

Question 8

Therapist factors: adherence types

Answer 8

concrete adherence: cognitive techniques, behavioral techniques, HW

abstract adherence: broader discussions of therapy relevant issues

Question 9

Therapeutic factors: Adherence and alliance study

Answer 9

findings:

• concrete adherence in session 2 led to improvement in symptoms, whereas alliance and Rogerian constructs did not
• improvement in depression leads to more concrete adherence and better alliance

-these findings were replicated

Question 10

Conclusions from research on adherence and alliance

Answer 10

greater focus on CT skills leads to better outcomes
symptom improvement leads to better alliances, not the other way around
but alliances are generally good in trials of CT, so cant say if poor alliances lead to poor outcomes

Question 11

Moderator defintion

Answer 11

a variable that affects the relationship between two other variables (magnitude or direction)

Question 12

Moderator: therapist competence

Answer 12

therapist competence matters generally, but especially in challenging cases (comorbidity, age of onset, and chronicity)

Question 13

Moderator: Sudden gains

Answer 13

-a large improvement in symptoms in a single between session interval that breaks from general average, gradual decline
Criteria:
1) large in absolute magnitude (at least 7 BDI points)
2) large in relative magnitude (representing at least 25% of the pre-gain session’s BDI score)
3) large relative to symptom fluctuation (significantly higher mean in three pre-gain sessions than in three post-gain sessions in order to rule out random fluctuation)

Question 14

Sudden gain research

Answer 14

patients who experienced sudden gains had greater total improvement and higher rates of recovery

upward spiral: cognitive change – sudden gain – increased alliance – more cognitive change – more improvement in alliance and symptoms??

sudden gain research gives credence to cognitive mediation model

Question 15

sudden gains in CPT vs IPT

Answer 15

more sudden gains in CPT, maybe because IPT includes more external variables so there’s more ups and downs

Question 16

Sudden gains in treatment resistant depression

Answer 16

study with random matching of patients with sudden gains

greater therapist competence in case conceptualization and greater patient hope differentiated patients with sudden gains from those without gains

consistent with upward spiral hypothesis

sudden gain predictors are quality of life and lack of comorbidities

Question 17

Process outcome research - how to demonstrate that a therapeutic variable/process is causally related to an outcome

Answer 17

covariation - weak evidence
temporal precedence - better evidence
non-spuriousness - best evident (experimental manipulation of process variable shown to have effect on outcome)