Cognitive change in cognitive-behavioural therapy v. pharmacotherapy for adult depression: a longitudinal mediation analysis

One-year follow-up of the effectiveness and mediators of cognitive behavioural therapy among adults with attention-deficit/hyperactivity disorder: secondary outcomes of a randomised controlled trial

BACKGROUND

The long-term effectiveness of cognitive behavioural therapy (CBT) in medicated attention-deficit/hyperactivity disorder (ADHD) adults with residual symptoms needs to be verified across multiple dimensions, especially with respect to maladaptive cognitions and psychological quality of life (QoL). An exploration of the mechanisms underlying the additive benefits of CBT on QoL in clinical samples may be helpful for a better understanding of the CBT conceptual model and how CBT works in medicated ADHD.

METHODS

We conducted a secondary analysis of a randomised controlled trial including 98 medicated ADHD adults with residual symptoms who were randomly allocated to the CBT combined with medication (CBT + M) group or the medication (M)-only group. Outcomes included ADHD-core symptoms (ADHD Rating Scale), depression symptoms (Self-rating Depression Scale), maladaptive cognitions (Automatic Thoughts Questionnaire and Dysfunctional Attitude Scale), and psychological QoL (World Health Organization Quality of Life-Brief Version-psychological domain). Mixed linear models (MLMs) were used to analyse the long-term effectiveness at one-year follow-up, and structural equation modeling (SEM) was performed to explore the potential mechanisms of CBT on psychological QoL.

RESULTS

ADHD patients in the CBT + M group outperformed the M-only group in reduction of ADHD core symptoms (d = 0.491), depression symptoms (d = 0.570), a trend of reduction of maladaptive cognitions (d = 0.387 and 0.395, respectively), and improvement of psychological QoL (d = - 0.433). The changes in above dimensions correlated with each other (r = 0.201 ~ 0.636). The influence of CBT on QoL was mediated through the following four pathways: 1) changes in ADHD core symptoms; 2) changes in depressive symptoms; 3) changes in depressive symptoms and then maladaptive cognitions; and 4) changes firstly in depressive symptoms, maladaptive cognitions, and then ADHD core symptoms.

CONCLUSIONS

The long-term effectiveness of CBT in medicated ADHD adults with residual symptoms was further confirmed. The CBT conceptual model was verified in clinical samples, which would be helpful for a deeper understanding of how CBT works for a better psychological QoL outcome.

TRIAL REGISTRATION

ChiCTR1900021705 (2019-03-05).

Omega-3 Fatty Acids for Depression in the Elderly and Patients with Dementia: A Systematic Review and Meta-Analysis

This study aimed to evaluate the efficacy of omega-3 fatty acid supplementation interventions in improving depression in patients with dementia. To achieve this objective, randomized controlled trials (RCTs) were identified from primary electronic databases, focusing on the relationship between omega-3 fatty acids and depression in patients with dementia. The primary outcome was the impact of omega-3 fatty acids on post-intervention depression in patients with dementia, with subgroup analyses conducted based on the type of intervention (docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) combination), duration of intervention (3 months, 6 months, 12 months, ≥24 months), cognitive function (ranging from mild cognitive impairment (MCI) to severe dementia), and daily dosage (high, medium, low, applicable to both DHA and EPA). The study has been duly registered with PROSPERO (registration ID: CRD42023408744). A meta-analysis of five studies (n = 517) included in nine systematic reviews showed that omega-3 supplementation had a non-significant trend toward affecting depressive symptoms in patients with dementia (standardized mean difference (SMD): 0.147; 95% confidence interval (CI): -0.324 to 0.049; p = 0.141). Subgroup analyses revealed that DHA supplementation significantly reduced depressive symptoms (SMD: -0.247; p = 0.039). There was no significant effect for high (SMD: -0.169; 95% CI: -0.454 to 0.116; p = 0.246) or medium (SMD: -0.061; 95% CI: -0.228 to 0.105; p = 0.470) doses of EPA. However, low doses of EPA were significantly effective (SMD: -0.953; 95% CI: -1.534 to -0.373; p = 0.001), with notable improvements in patients with MCI (SMD: -0.934; p < 0.001). The study concludes that omega-3 fatty acids, particularly through DHA supplementation, may alleviate depressive symptoms in patients with MCI. Given the limited sample size, further long-term RCTs are recommended to better understand the efficacy and optimal management of omega-3 supplementation in this population using different dosages.

Distorted thoughts as a mediator of depressive symptoms in patients with major depressive disorder: a longitudinal study

BACKGROUND

Distorted thoughts are common in Major Depressive Disorder (MDD), and can impact patients' perceptions of depression severity, and predict chronicity and treatment response. This study aimed to investigate whether distorted thoughts mediate depressive symptoms in MDD over a 6-month period.

METHOD

These are secondary results from a study that followed 119 patients diagnosed with moderate to severe MDD for 6 months. Diagnoses were confirmed by the Structured Interview for DSM-IV (SCID-CV). The analysis was composed of results from the Hamilton Depression Rating Scale (HAMD-17), the Montgomery-Asberg Depression Rating Scale (MADRS), the second edition of the Beck Depression Inventory (BDI-II), and the Depression Thoughts Scale (DTS) collected at weeks 1, 8, 12 and 24.

RESULTS

Results showed that the DTS mediated the relationship between depressive symptoms experienced approximately 3 months after starting antidepressant treatment.

CONCLUSION

Cognitive distortions were linked as a mediator to depressive symptoms, highlighting the importance of early psychological interventions in patients with MDD who exhibit these distortions.

TRIAL REGISTRATION

NCT02268487.

Testing Mechanisms of Change for Text Message-Delivered Cognitive Behavioral Therapy: Randomized Clinical Trial for Young Adult Depression

BACKGROUND

Current psychiatric epidemiological evidence estimates that 17% of young adults (aged 18-25 years) experienced a major depressive episode in 2020, relative to 8.4% of all adults aged ≥26 years. Young adults with a major depressive episode in the past year are the least likely to receive treatment for depression compared with other age groups.

OBJECTIVE

We conducted a randomized clinical trial following our initial 4-week SMS text message-delivered cognitive behavioral therapy (CBT-txt) for depression in young adults. We sought to test mechanisms of change for CBT-txt.

METHODS

Based on participant feedback, outcome data, and the empirical literature, we increased the treatment dosage from 4-8 weeks and tested 3 mechanisms of change with 103 young adults in the United States. Participants were from 34 states, recruited from Facebook and Instagram and presenting with at least moderate depressive symptomatology. Web-based assessments occurred at baseline prior to randomization and at 1, 2, and 3 months after enrollment. The primary outcome, the severity of depressive symptoms, was assessed using the Beck Depression Inventory II. Behavioral activation, perseverative thinking, and cognitive distortions were measured as mechanisms of change. Participants were randomized to CBT-txt or a waitlist control condition. Those assigned to the CBT-txt intervention condition received 474 fully automated SMS text messages, delivered every other day over a 64-day period and averaging 14.8 (SD 2.4) SMS text messages per treatment day. Intervention texts are delivered via TextIt, a web-based automated SMS text messaging platform.

RESULTS

Across all 3 months of the study, participants in the CBT-txt group showed significantly larger decreases in depressive symptoms than those in the control group (P<.001 at each follow-up), producing a medium-to-large effect size (Cohen d=0.76). Over half (25/47, 53%) of the treatment group moved into the "high-end functioning" category, representing no or minimal clinically significant depressive symptoms, compared with 15% (8/53) of the control condition. Mediation analysis showed that CBT-txt appeared to lead to greater increases in behavioral activation and greater decreases in cognitive distortions and perseverative thinking across the 3-month follow-up period, which were then associated with larger baseline to 3-month decreases in depression. The size of the indirect effects was substantial: 57%, 41%, and 50% of the CBT-txt effect on changes in depression were mediated by changes in behavioral activation, cognitive distortions, and perseverative thinking, respectively. Models including all 3 mediators simultaneously showed that 63% of the CBT-txt effect was mediated by the combined indirect effects.

CONCLUSIONS

Results provide evidence for the efficacy of CBT-txt to reduce young adult depressive symptoms through hypothesized mechanisms. To the best of our knowledge, CBT-txt is unique in its SMS text message-delivered modality, the strong clinical evidence supporting efficacy and mechanisms of change.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05551702; https://clinicaltrials.gov/study/NCT05551702.

Nonpharmacologic and Pharmacologic Treatments of Adult Patients With Major Depressive Disorder: A Systematic Review and Network Meta-analysis for a Clinical Guideline by the American College of Physicians

BACKGROUND

Primary care patients and clinicians may prefer alternative options to second-generation antidepressants for major depressive disorder (MDD).

PURPOSE

To compare the benefits and harms of nonpharmacologic treatments with second-generation antidepressants as first-step interventions for acute MDD, and to compare second-step treatment strategies for patients who did not achieve remission after an initial attempt with antidepressants.

DATA SOURCES

English-language studies from several electronic databases from 1 January 1990 to 8 August 2022, trial registries, gray literature databases, and reference lists to identify unpublished research.

STUDY SELECTION

2 investigators independently selected randomized trials of at least 6 weeks' duration.

DATA EXTRACTION

Reviewers abstracted data about study design and conduct, participants, interventions, and outcomes. They dually rated the risk of bias of studies and the certainty of evidence for outcomes of interest.

DATA SYNTHESIS

65 randomized trials met the inclusion criteria; eligible data from nonrandomized studies were not found. Meta-analyses and network meta-analyses indicated similar benefits of most nonpharmacologic treatments and antidepressants as first-step treatments. Antidepressants had higher risks for discontinuation because of adverse events than most other treatments. For second-step therapies, different switching and augmentation strategies provided similar symptomatic relief. The certainty of evidence for most comparisons is low; findings should be interpreted cautiously.

LIMITATIONS

Many studies had methodological limitations or dosing inequalities; publication bias might have affected some comparisons. In some cases, conclusions could not be drawn because of insufficient evidence.

CONCLUSION

Although benefits seem to be similar among first- and second-step MDD treatments, the certainty of evidence is low for most comparisons. Clinicians and patients should focus on options with the most reliable evidence and take adverse event profiles and patient preferences into consideration.

PRIMARY FUNDING SOURCE

American College of Physicians. (PROSPERO: CRD42020204703).

Longitudinal changes in intolerance of uncertainty and worry severity during CBT for generalized anxiety disorder

Intolerance of uncertainty (IU) is a key construct in generalized anxiety disorder (GAD), but little is known about the concurrent and temporal patterns of associations between IU and GAD symptom severity during treatment. In addition, most of the extant literature focuses on IU as a unidimensional construct, whereas some researchers conceptualize IU as being comprised of two dimensions, inhibitory and prospective IU. Ninety individuals with GAD completed measures of IU and worry severity at pre-treatment, session 4, session 8, and end of treatment (session 12), during group-based cognitive behavior therapy (CBT) for GAD. Longitudinal multilevel modeling showed that IU predicted worry severity concurrently, but not prospectively over time; this pattern of associations was found with the total IUS score and the inhibitory (but not prospective) subscale score. Further, the relationship between IU total scores and worry severity became stronger over time. The relationship between inhibitory (but not prospective) IU and worry also became stronger over time. When the order of the variables in the model was reversed, worry severity also predicted concurrent but not future IU. Therefore, change in IU is associated with change in worry throughout the course of CBT, particularly as treatment progresses, though its directional association as a cause and/or effect remains unclear.

Mediators of change in depressed mood following pain rehabilitation among participants with mild, moderate, or severe depressive symptoms

BACKGROUND

Prior research indicates that depression and chronic pain commonly co-exist and impact each other. Interdisciplinary pain rehabilitation programs (IPRPs) have been shown to lead to statistically and clinically significant improvements for patients who report both depressed mood and chronic pain, however there is a gap in the literature regarding the mechanisms by which these improvements occur.

METHODS

This two-site, distinct sample study (Study 1: N = 303, 10-week, individual format, ACT-based program; Study 2: N = 406, 3-week, group format, CBT-based program) evaluated mediators of treatment improvement in depressive symptoms among adult IPRP participants who reported elevated depressive symptoms at program admission and examined treatment mechanisms for depressive symptoms.

RESULTS

Self-reported pain self-efficacy and pain catastrophizing - particularly the helplessness domain - mediated the treatment-related change in depression among IPRP participants with elevated depressive symptoms across the two sites and samples. In one sample, full mediation was achieved while in the other sample, partial mediation was achieved. Participants in both samples showed improvement on all measures.

LIMITATIONS

This study relied on self-report measures of depressive severity and not clinical diagnosis. Results may not generalize to other populations of patients with chronic pain. There was no control condition in either study.

CONCLUSION

Increasing pain self-efficacy and decreasing a sense of helplessness are important treatment targets among IPRP participants who endorse symptoms of depression.

The Effect of Noninvariance on the Estimation of the Mediated Effect in the Two-Wave Mediation Model

The two-wave mediation model is the most suitable model for examining mediation effects in a randomized intervention and includes measures taken at pretest and posttest. When using self-report measures, the meaning of responses may change for the treatment group over the course of the intervention and result in noninvariance across groups at posttest, a phenomenon referred to as response shift. We investigate how the mediated effect would be impacted by noninvariance when using sum scores (i.e., assuming invariance). In a Monte Carlo simulation study, the magnitude and proportion of items that had noninvariant intercepts, the direction of noninvariance, number of items, effect size of the mediated effect and sample size were varied. Results showed increased Type I and Type II errors due to a biased estimate of the intervention effect on the mediator resulting from noninvariance. Thus, measurement noninvariance could lead to erroneous conclusions about the process underlying the intervention.

Relationships between worry and depressive symptoms during two group therapies for generalized anxiety disorder

ABSTRACT Objective: Generalized anxiety disorder (GAD) is a chronic and disabling disorder associated with various impairments and shows a significant prevalence in the worldwide and Brazilian populations. This study aimed to investigate the longitudinal relationship of two symptoms relevant to the disorder (worry and depressive symptoms) in the context of a randomized clinical trial (RCT) by using a cross-lagged panel model (CLPM) analysis. Methods: A total of 92 adult patients with GAD were randomized to receive ten sessions of either acceptance‐based group behavioral therapy (ABBT) or nondirective supportive group therapy (NDST). Treatment had four time-point measures. Worries were measured using the Penn State Worry Questionnaire (PSWQ), and depression was measured using the Depression Anxiety Stress Scales (DASS-D). Results: The NDST model revealed significant paths from worry to depression (first wave) and from depression to worry (second wave). There was no other significant cross-lagged effect. These data show that there was an influence between symptoms only during one of the treatment groups, and without a homogeneous and constant pattern in any of the cross-lagged routes. Conclusion: A supportive group psychotherapy potentially interferes with the pattern of the direct relationship between worries and depressive symptoms in adults with GAD.

How does cognitive behavioural therapy for insomnia work? A systematic review and meta-analysis of mediators of change

Insomnia is prevalent and debilitating, comprising sustained difficulties initiating or maintaining sleep. Cognitive-behavioural therapy for insomnia (CBT-I) is a multicomponent intervention recommended as the first-line treatment, but the mediators of change remain unclear. This systematic review and meta-analysis aimed to synthesise and evaluate the evidence for potential mediators of CBT-I. Searches were performed for studies published until February 2021, reporting on mediation analyses with CBT-I. Seventeen unique samples of adults with insomnia (20 studies, N = 3125) were included. Two-stage structural equation modelling was applied to the available data, where 7 studies examined the cognitive mediator, 'dysfunctional beliefs about sleep', 5 studies examined a hyperarousal mediator, and 3 studies examined the behavioural mediator, 'time in bed'. There was evidence in support of changes in dysfunctional beliefs as a cognitive mediator of insomnia symptom improvement following CBT-I. There was more limited evidence in support of changes in hyperarousal-related mediators, and no significant effect of time in bed as a mediator. Numerous studies recorded diary-based measures of potential behavioural mediators, but analyses of these variables were not typically conducted. The most serious limitation of the evidence base is that the temporal precedence of mediator changes cannot be established. Future studies should consider: i) using mid-treatment measurements of mediator changes; ii) reporting on mediator psychometric properties; and iii) explicitly stating analyses as pre-specified or exploratory.

Nonpharmacological interventions for relapse prevention in unipolar depression: A network meta-analysis

BACKGROUND

The development of prophylactic interventions for major depressive disorder (MDD) is an important issue in clinical practice. We aimed to compare the relative efficacy of nonpharmacological interventions for relapse prevention in adult patients with MDD.

METHODS

Randomized controlled trials investigating nonpharmachological interventions for relapse prevention were included. A Bayesian network meta-analysis was performed. Hazard ratios are reported as effect sizes with 95% credible intervals. Global inconsistency, local inconsistency, heterogeneity, and transitivity were evaluated. Confidence for the results comparing the active treatment with control conditions or antidepressant medicine (ADM) was assessed.

RESULTS

Thirty-six trials were included. Most nonpharmacological interventions were various forms of psychotherapy; others were noninvasive neurostimulation techniques (3 studies with electroconvulsive therapy and 1 study with transcranial magnetic stimulation). Psychotherapy as a monotherapy following ADM or psychotherapy produced significantly better outcomes than control conditions, and there was no significant difference between psychotherapy and ADM. The combination of psychotherapy and ADM was superior to either treatment alone. The results were similar for patients with at least 3 previous episodes. Neurostimulation techniques were also superior to controls, either as a monotherapy or combined with ADM.

CONCLUSIONS

Our study provided evidence that psychotherapy as a monotherapy following ADM or psychotherapy was effective and performed as well as ADM for relapse prevention. Neurostimulation techniques also showed promising results but more studies are needed to confirm their efficacy. These findings may be informative for clinical practice and inspire future research.