Motivational Interviewing and Cognitive Behavioural Therapy for Generalized Anxiety Disorder
Condition: Anxiety Disorders; Generalized Anxiety Disorder
MeSH terms: Anxiety Disorders
Study type: Interventional

Summary: 
      The current study examines whether change-readiness, and consequently treatment outcome, can
      be enhanced in Cognitive Behavioral Therapy (CBT) for severe Generalized Anxiety Disorder
      (GAD) by adding a brief course of Motivational Interviewing (MI adapted for anxiety, Westra &
      Dozois, 2003) before and during CBT when motivation wanes. 106 individuals with severe GAD
      will be randomly assigned to receive an equal number of sessions of either MI and CBT (MI-CBT
      arm) or CBT alone (CBT alone arm). It is expected that the MI-CBT arm relative to the CBT
      alone arm will show lower levels of resistance in CBT, higher levels of homework compliance
      and therapeutic alliance, better moment-to-moment interpersonal process, and consequently
      superior outcomes - both post-treatment and at 6 and 12 month follow-ups.
    

Detailed description: 
      The proposed study builds on the findings of the clinical trial by Westra, Arkowitz and
      Dozois (2009), and aims to: (1) provide a powerful test of the value of adding MI to CBT for
      high severity GAD (as pilot data has indicated that individuals with severe GAD may
      preferentially benefit from the addition of MI to CBT), (2) employ treatment procedures
      generalizable to clinical practice, and (3) examine the mechanisms underlying any additive
      treatment benefit. 106 individuals with a principal diagnosis of GAD and of high worry
      severity will be randomly assigned to receive either 4 sessions of MI followed by 11 sessions
      of CBT (MI-CBT arm) or 15 sessions of CBT (CBT alone arm). Both groups will also receive 2
      follow-up CBT treatment sessions at 1 and 3 months post-treatment. Each therapist will
      deliver all treatment components, treatments will appear seamless to clients, and therapists
      will be nested within treatment group to control for allegiance effects and avoid
      cross-contamination of the therapies. In order to increase generalizability to clinical
      practice, in the CBT phase for the MI-CBT arm, therapists will shift to MI in the presence of
      empirically derived markers of resistance and shift back to CBT when resistance has
      diminished. In the CBT alone arm therapists will respond to resistance using manualized
      recommendations derived from leading CBT theorists for the management of resistance. Anxiety
      and related symptoms, motivation, and treatment engagement will be assessed at various points
      during treatment, and at 6 and 12 months post-treatment. A multi-method approach to
      assessment will be used, including self-report, clinician-report, clinician-administered,
      observer-rated, and interview-based measures. Importantly, we will include not only
      traditional outcome measures, but also process measures (e.g., observer-coded interpersonal
      behavior, interview-based derivation of client experiences) to investigate possible
      mechanisms underlying any additive treatment benefit. In addition, all therapy sessions will
      be videotaped and assessed by independent raters for protocol adherence.

      The specific hypotheses are as followed:

      Hypothesis 1: Worry, Anxiety, & Related Symptoms. The MI-CBT arm will show greater reductions
      in worry, anxiety, and related symptoms (depression, disability, maladaptive beliefs about
      worry, life satisfaction) and a greater percentage of treatment responders (using clinical
      significance criteria) across the treatment period and at follow-up (FU), compared to the CBT
      alone arm.

      Hypothesis 2: Motivation and Resistance. Over the course of early treatment (i.e., sessions 1
      to 4), the MI-CBT arm will demonstrate greater increases in motivation compared to the CBT
      alone arm. In addition, the MI-CBT arm will exhibit lower in-session resistance during early
      (sessions 5 & 7), middle (sessions 10 & 12), and late (sessions 15 & 17) phases of treatment.

      Hypothesis 3: Homework Compliance. The MI-CBT arm will show greater client- and
      therapist-rated homework compliance throughout CBT treatment compared to the CBT alone arm.

      Hypothesis 4a: Interpersonal Processes between Clients and Therapists. Compared to CBT alone
      clients, MI-CBT clients and therapists will report higher working alliance quality during
      both the initial MI sessions and subsequent phases of CBT. Furthermore, moment-to-moment
      interpersonal processes between client and therapist during early, middle, and late treatment
      are expected to be characterized by more adaptive processes (e.g., higher affiliation and
      less hostility) in the MI-CBT vs. CBT alone arms.

      Hypothesis 4b. Interpersonal Processes During Resistance. During episodes of client
      resistance (identified with resistance coding), therapist and client exchanges in MI-CBT are
      expected to be characterized by more adaptive processes (i.e., higher affiliation, less
      hostility, and greater client autonomy-preservation) compared to CBT alone. Further, when a
      small subset of clients (5 per treatment group) are interviewed about their experiences of
      resistance episodes, we expect client accounts in the MI-CBT arm to be characterized more
      positively (e.g., more supportive of client autonomy, more conducive to increased engagement
      vs. disengagement with treatment) compared to CBT alone.

      Hypothesis 5: Mediation of Therapeutic Outcomes. We expect that increased motivation and
      reduced resistance in MI-CBT, compared to CBT alone, will lead to higher levels of engagement
      in the CBT (better homework compliance and therapeutic alliance), which will result in
      greater worry reduction.
    

Intervention name(s): Motivational Interviewing and Cognitive Behavioural Therapy
Intervention type(s): Behavioral
Intervention description(s): Participants with a diagnosis of severe Generalized Anxiety Disorder will be randomly assigned to receive either 4 weekly sessions of MI followed by 11 weekly sessions of CBT (MI-CBT arm) or 15 weekly sessions of CBT (CBT alone arm). Both groups will also receive 2 follow-up CBT treatment sessions at 1 and 3 months post-treatment. In order to increase generalizability to clinical practice, in the CBT phase for the MI-CBT arm, therapists will shift to MI in the presence of empirically derived markers of resistance and shift back to CBT when resistance has diminished. In the CBT alone arm therapists will respond to resistance using manualized recommendations derived from leading CBT theorists for the management of resistance.
Other intervention name(s): Motivational Interviewing; Cognitive Behavioral Therapy
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Anxiety; Generalized Anxiety Disorder; Motivational Interviewing; Cognitive Behavioural Therapy; Psychotherapy