Patients' comprehension and skill usage as a putative mediator of change or an engaged target in cognitive therapy: Preliminary findings

How can the DSM-5 alternative model of personality disorders advance understanding of depression?

BACKGROUND

The DSM-5 introduced an alternative model of personality disorder (AMPD) that includes personality dysfunction plus maladaptive-range traits. This study clarifies relations of depression diagnoses and symptoms with AMPD personality pathology.

METHOD

Two samples (Ns 402 and 601) of outpatients and community-dwelling adults completed four depression (criteria met for major depressive disorder and dysthymia; dysphoria and low well-being scales), ten trait (two scales for each of five domains-negative affectivity, detachment, disinhibition, antagonism, psychoticism), and eight dysfunction (four scales for each of two domains-self- and interpersonal pathology) measures. Diagnoses were made using a semi-structured interview; other measures were self-reports. We quantified cross-sectional relations between depression and personality pathology with correlation and multiple regression analyses.

RESULTS

Collectively (median R²; ps < 0.0001), the trait (0.46) and dysfunction (0.50) scales predicted the depression measures strongly, with most predictive power shared (0.41) between traits and dysfunction. However, trait and dysfunction scales altogether predicted depression (median R² = 0.54) more strongly than either domain alone, ps < 0.0001. Participants with depression diagnoses showed elevations on all nonadaptive trait and personality dysfunction measures, particularly negative temperament/affectivity and self-pathology measures.

LIMITATIONS

Generalization of findings to other populations (e.g., adolescents), settings (e.g., primary care), and measures (e.g., traditional personality disorder diagnoses) is uncertain. Cross-sectional analyses did not test changes over time or establish causality.

CONCLUSIONS

The AMPD is highly relevant to depression. Assessment of personality pathology, including both personality dysfunction and maladaptive-range traits, stands to advance understanding of depression in adults.

Does Symptom Linkage Density Predict Outcomes in Cognitive Therapy for Recurrent Depression?

Background

Acute-phase cognitive therapy (CT) is an efficacious treatment for major depressive disorder (MDD), but how CT helps patients is incompletely understood. As a potential means to clarify CT mechanisms, we defined "symptom linkage density" (SLD) as a patient's mean time-lagged correlation among nine depressive symptoms across 13 weekly assessments. We hypothesized that patients with higher SLD during CT have better outcomes (treatment response, and fewer symptoms after response), and we explored whether SLD correlated with other possible CT processes (growth in social adjustment and CT skills).

Method

Data were drawn from two clinical trials of CT for adult outpatients with recurrent MDD (primary sample n = 475, replication sample n = 146). In both samples, patients and clinicians completed measures of depressive symptoms and social adjustment repeatedly during CT. In the primary sample, patients and cognitive therapists rated patients' CT skills. After CT, responders were assessed for 32 (primary sample) or 24 (replication sample) additional months to measure long-term depression outcomes.

Results

Higher SLD predicted increases in social adjustment (both samples) and CT skills (primary sample) during CT, CT response (both samples), and lower MDD severity for at least 2 years after CT response (both samples). Analyses controlled patient-level symptom means and variability to estimate SLD's incremental predictive validity.

Conclusions

These novel findings from two independent samples with longitudinal follow-up require further replication and extension. SLD may reflect or facilitate generalization of CT skills, improvement in social functioning, or other processes responsible for CT's shorter and longer term benefits.

Do patients' cognitive therapy skills predict personality change during treatment of depression?

BACKGROUND

Psychological interventions can change personality, including increasing positive temperament (extraversion) and decreasing negative temperament (neuroticism), but why these changes occur is unclear. The current study tested the extent to which patients' acquisition and use of skills taught in cognitive therapy (CT) correlated with changes in positive and negative temperament during treatment of depression.

METHOD

Outpatients (N = 351) with recurrent major depressive disorder (MDD) were enrolled in a 12-week CT protocol. Temperament (early and late in CT), patient skills (mid and late in CT), and depressive symptoms (early, mid, and late in CT) were measured repeatedly.

RESULTS

Patients with greater acquisition and use of CT skills showed significantly larger increases in positive temperament and larger decreases in negative temperament in path analyses. Effect sizes were small, median standardized |beta| = 0.13. Models controlled depressive symptom levels and changes.

CONCLUSIONS

Skills taught in CT for recurrent depression correlate with personality change during this efficacious treatment. The absence of measures of CT skills at baseline and personality mid-CT allows several interpretations of the current findings. Future research is needed to clarify whether patients' use of CT skills facilitates adaptive changes in personality during CT.

Do Cognitive Therapy Skills Neutralize Lifetime Stress to Improve Treatment Outcomes in Recurrent Depression?

Cognitive therapy (CT) is an efficacious treatment for major depressive disorder (MDD), but not all patients respond. Past research suggests that stressful life events (SLE; e.g., childhood maltreatment, emotional and physical abuse, relationship discord, physical illness) sometimes reduce the efficacy of depression treatment, whereas greater acquisition and use of CT skills may improve patient outcomes. In a sample of 276 outpatient participants with recurrent MDD, we tested the hypothesis that patients with more SLE benefit more from CT skills in attaining response and remaining free of relapse/recurrence. Patients with more pretreatment SLE did not develop weaker CT skills, on average, but were significantly less likely to respond to CT. However, SLE predicted non-response only for patients with relatively weak skills, and not for those with stronger CT skills. Similarly, among acute-phase responders, SLE increased risk for MDD relapse/recurrence among patients with weaker CT skills. Thus, the combination of more SLE and weaker CT skills forecasted negative outcomes. These novel findings are discussed in the context of improving CT for depression among patients with greater lifetime history of SLE and require replication before clinical application.