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Psychotherapies are first-line treatments for most mental disorders, but their absolute outcomes (i.e., response and remission rates) are not well studied, despite the relevance of such information for health care users, providers and policy makers. We aimed to examine absolute and relative outcomes of psychotherapies across eight mental disorders: major depressive disorder (MDD), social anxiety disorder, panic disorder, generalized anxiety disorder (GAD), specific phobia, post-traumatic stress disorder (PTSD), obsessive-compulsive disorder (OCD), and borderline personality disorder (BPD). We used a series of living systematic reviews included in the Metapsy initiative (www.metapsy.org), with a common strategy for literature search, inclusion of studies and extraction of data, and a common format for the analyses. Literature search was conducted in major bibliographical databases (PubMed, PsycINFO, Embase, and the Cochrane Register of Controlled Trials) up to January 1, 2023. We included randomized controlled trials comparing psychotherapies for any of the eight mental disorders, established by a diagnostic interview, with a control group (waitlist, care-as-usual, or pill placebo). We conducted random-effects model pairwise meta-analyses. The main outcome was the absolute rate of response (at least 50% symptom reduction between baseline and post-test) in the treatment and control conditions. Secondary outcomes included the relative risk (RR) of response, and the number needed to treat (NNT). Random-effects meta-analyses of the included 441 trials (33,881 patients) indicated modest response rates for psychotherapies: 0.42 (95% CI: 0.39-0.45) for MDD; 0.38 (95% CI: 0.33-0.43) for PTSD; 0.38 (95% CI: 0.30-0.47) for OCD; 0.38 (95% CI: 0.33-0.43) for panic disorder; 0.36 (95% CI: 0.30-0.42) for GAD; 0.32 (95% CI: 0.29-0.37) for social anxiety disorder; 0.32 (95% CI: 0.23-0.42) for specific phobia; and 0.24 (95% CI: 0.15-0.36) for BPD. Most sensitivity analyses broadly supported these findings. The RRs were significant for all disorders, except BPD. Our conclusion is that most psychotherapies for the eight mental disorders are effective compared with control conditions, but absolute response rates are modest. More effective treatments and interventions for those not responding to a first-line treatment are needed.

Background. It is not clear whether the amount and frequency of psychotherapy is associated with treatment effects for adult depression. We investigated whether a number of indicators of the amount and frequency of psychotherapy were related to the treatment effects in randomized controlled trials (RCTs) comparing individual, face-to-face psychotherapy to a control group (e.g., care-as-usual [CAU] or waitlist condition [WL]).

Methods. Four databases were systematically searched, and meta-regression analyses conducted to assess the relationship between the effect size (Hedges' g) of the treatment and number of sessions, duration of psychotherapy, total contact time with the therapist, and number of sessions per week.

Results. We included 176 studies (210 comparisons) with 15,158 participants. We did not find a relationship between the effect size, and number of sessions, or total contact time. There was a small negative association between duration of treatment and the effect size, an additional week of treatment was related to a 0.014 decrease in the effect size. In addition, there was a strong association between number of sessions per week and the effect size, an increase from one to two sessions per week was related to an effect size higher by 0.596. Both associations were no longer significant when controlling for characteristics of studies.

Limitations. The current findings are correlational, future research should thus address this question in an RCT. Conclusions. We should deliver brief therapies, and thus shorten waiting lists. More sessions, if necessary, should be delivered with higher frequency and over a shorter period of time.

Importance. Suicidal ideation and suicide attempts are debilitating mental health problems that are often treated with indirect psychotherapy (ie, psychotherapy that focuses on other mental health problems, such as depression or personality disorders). The effects of direct and indirect psychotherapy on suicidal ideation have not yet been examined in a meta-analysis, and several trials have been published since a previous meta-analysis examined the effect size of direct and indirect psychotherapy on suicide attempts.

Objective.  To investigate the effect sizes of direct and indirect psychotherapy on suicidal ideation and the incidence of suicide attempts.

Data Sources. PubMed, Embase, PsycInfo, Web of Science, Scopus, and the Cochrane Central Register of Controlled Trials were searched for articles published up until April 1, 2023.

Study Selection. Randomized clinical trials of psychotherapy for any mental health problem, delivered in any setting, compared with any control group, and reporting suicidal ideation or suicide attempts were included. Studies measuring suicidal ideation with 1 item were excluded.

Data Extraction and Synthesis. PRISMA guidelines were followed. Summary data were extracted by 2 independent researchers and pooled using 3-level meta-analyses.

Main Outcomes and Measures. Hedges g was pooled for suicidal ideation and relative risk (RR) was pooled for suicide attempts.

Results. Of 15 006 studies identified, 147 comprising 193 comparisons and 11 001 participants were included. Direct and indirect psychotherapy conditions were associated with reduced suicidal ideation (direct: g, −0.39; 95% CI, −0.53 to −0.24; _I_2, 83.2; indirect: g, −0.30; 95% CI, −0.42 to −0.18; _I_2, 52.2). Direct and indirect psychotherapy conditions were also associated with reduced suicide attempts (direct: RR, 0.72; 95% CI, 0.62 to 0.84; _I_2, 40.5; indirect: RR, 0.68; 95% CI, 0.48 to 0.95; _I_2, 0). Sensitivity analyses largely confirmed these results.

Conclusions and Relevance. Direct and indirect interventions had similar effect sizes for reducing suicidal ideation and suicide attempts. Suicide prevention strategies could make greater use of indirect treatments to provide effective interventions for people who would not likely seek treatment for suicidal ideation or self-harm.

When studies use different scales to measure continuous outcomes, standardised mean differences (SMD) are required to meta-analyse the data. However, outcomes are often reported as endpoint or change from baseline scores. Combining corresponding SMDs can be problematic and available guidance advises against this practice. We aimed to examine the impact of combining the two types of SMD in meta-analyses of depression severity. We used individual participant data on pharmacological interventions (89 studies, 27,409 participants) and internet-delivered cognitive behavioural therapy (iCBT; 61 studies, 13,687 participants) for depression to compare endpoint and change from baseline SMDs at the study level. Next, we performed pairwise (PWMA) and network meta-analyses (NMA) using endpoint SMDs, change from baseline SMDs, or a mixture of the two. Study-specific SMDs calculated from endpoint and change from baseline data were largely similar, although for iCBT interventions 25% of the studies at 3 months were associated with important differences between study-specific SMDs (median 0.01, IQR −0.10, 0.13) especially in smaller trials with baseline imbalances. However, when pooled, the differences between endpoint and change SMDs were negligible. Pooling only the more favourable of the two SMDs did not materially affect meta-analyses, resulting in differences of pooled SMDs up to 0.05 and 0.13 in the pharmacological and iCBT datasets, respectively. Our findings have implications for meta-analyses in depression, where we showed that the choice between endpoint and change scores for estimating SMDs had immaterial impact on summary meta-analytic estimates. Future studies should replicate and extend our analyses to fields other than depression.

Objective. There is consistent evidence that cognitive behavioral therapies (CBTs) are effective interventions for adult depression. While some evidence has compared these effects in different countries, no prior systematic review and meta-analysis has compared the efficacy of CBTs between Chinese and people from the rest of the world. The current meta-analysis addressed this gap by a systematic review of eligible studies from Chinese and worldwide databases.

Method. Hedges' g was calculated using a random-effects model. Subgroup analyses and multilevel meta-analytic models were conducted to examine the relationship among effect sizes and the characteristics in Chinese studies. Metaregression analyses were conducted to explore the difference of the efficacy of CBTs between Chinese studies and non-Chinese studies after controlling for the moderators.

Results. A total of 34 (n = 3,710) studies in China and 307 (n = 30,333) studies from the rest of the world were included. The effect size of CBTs on depression for Chinese participants was 1.19 (95% CI [0.86, 1.52]), which was higher (Q = 4.63, p = .03) than the effect size of the rest of the world (0.82, 95% CI [0.74, 0.90]). After controlling for moderators, the effect size of Chinese studies was still higher than non-Chinese studies (β = 0.351, p = .011).

Conclusions. CBTs are effective interventions for adult depression and deserve more attention in China for depression management. Moderators related to study design, clinical features, and cultural factors need to be considered in the interpretation of the results.

Background. Although numerous studies have examined the effects of psychological treatments for obsessive-compulsive disorder (OCD), their overall effectiveness remains unclear. We aimed to estimate their overall effect by combining all available randomized controlled trials (RCTs) comparing psychological treatments to control groups for OCD.

Methods. We conducted a meta-analysis of 48 RCTs with 55 comparisons published between 1992 and 1 January 2023. The primary outcome was OCD symptom severity, with Hedges' g calculated at post-treatment and follow-up. Random-effects models were employed for all analyses, and the risk of bias was assessed.

Results. In general, psychological treatments demonstrated a significantly large effect (g = −1.14; 95% CI [−1.31 to −0.97]; I2 = 72.23%) on reducing OCD symptom severity post-treatment, this finding remained consistent across measures and after excluding outliers, but lost significance in the sensitivity analysis for only studies with low risk of bias. Type of treatment, control group and treatment format were associated with treatment effects. Moreover, more severe baseline OCD symptom severity predicted higher degree of treatment efficacy. No significant differences were observed in dropout rates between the treatment and control groups. Treatment effects lost significance at 3–6 and 6–12 month follow-ups. 87% of RCTs were rated at high risk of bias.

Conclusions. Psychological treatments are effective in reducing OCD symptom severity. However, caution should be exercised when interpreting these results due to the high heterogeneity and risk of bias across RCTs. Future studies with more rigorous methodology are required, as well as studies examining their long-term effectiveness.

This chapter looks into interpersonal psychotherapy (IPT) for depression in low- and middle-income countries (LMICs). It acknowledges depression as one of the most common disorders that results in considerable loss of quality of life in patients and their families. The World Health Organization (WHO) recommends IPT as a specialized treatment for depression. The chapter presents the research on IPT, a meta-analysis of the effects of IPT on adult depression, and the trials conducted in LMICs in comparison to IPT research in high-income countries. It suggests the effectiveness of IPT as a treatment for adult depression should not be any less in LMICs.

Background. Over the past decades dozens of randomized trials have shown that psychological treatments are more effective than care-as-usual (CAU). It could be expected that these treatments are implemented in routine care and that the response rates in usual care improve over time. The aim of the current meta-analysis is to examine if response and remission rates in usual care have improved over time.

Methods. We used an existing meta-analytic database of randomized controlled trials examining the effects of psychological treatments of depression and selected CAU control groups from these trials. We only included CAU conditions in primary care, specialized mental health care, perinatal care and general medical care. The response rate (50 % symptom reduction) was the primary outcome.

Results. We included 125 CAU control groups (8542 participants). The response rate for all CAU control groups was 0.22 (95 % CI: 0.19; 0.24) with high heterogeneity (I2 = 83; 95 % CI: 80; 85), with somewhat higher rates in primary care (0.27; 95 % CI: 0.23; 0.31). We found hardly any indications that the outcomes have improved over the years. The meta-regression analysis with publication year as predictor in the full dataset resulted in a coefficient of 0.1 (SE = 0.01; p = 0.0.35). A series of sensitivity analyses supported the main findings. Remission rates and pre-post effect sizes also did not significantly improve over time.

Conclusions. Response and remission rates in usual care are low, with the large majority of patients not responding or remitting, and the outcomes have probably not improved over time.

Background. Evidence-based treatments for adult depression include psychotherapy and pharmacotherapy, yet little is known about how baseline depression severity moderates treatment outcome.

Objectives. We aimed to compare the effects of psychotherapy and pharmacotherapy for adult depression and to examine the association between baseline depression severity and treatment outcome, converting multiple baseline depression measures into the scores of the Beck Depression Inventory, second edition (BDI-II).

Methods. We conducted systematic searches in bibliographical databases up to September 2022 to identify randomized controlled trials (RCTs) in which psychotherapy was compared with pharmacotherapy in the treatment of adult depression. Various meta-regressions using the baseline depression severity as a predictor of the relative effects of psychotherapy and pharmacotherapy were performed.

Results. We identified 65 RCTs including 7250 participants for the meta-analyses and 56 RCTs including 5548 participants for the meta-regression. We found no significant difference between psychotherapy and pharmacotherapy (g = −0.08, 95% CI: −0.2 to 0.04, p = 0.193) and baseline depression severity was not significantly associated with the relative effects of psychotherapy and pharmacotherapy (B = 0.0032, SE = 0.0096, p = 0.74). Results were similar in several sensitivity analyses.

Limitations. Limitations included the low quality of the included studies, and the omission of long-term effects and within-study variability.

Conclusions. We found no indication for a moderation effect of baseline depression severity on the relative effects of psychotherapy and pharmacotherapy. Thus, other factors such as availability and patients' preference must be considered when deciding for treatment options.

Introduction. Generalized anxiety disorder (GAD) is one of the most common mental disorders in adults. Psychotherapies are among the most recommended treatment choices for GAD, but which should be considered as first-line treatment still needs to be clarified.

Objectives. To examine the most effective and accepted psychotherapy for GAD both in the short and long-term, via a network meta-analysis.

Methods. We searched MEDLINE, Embase, PsycINFO, and the Cochrane Register of Controlled Trials – CENTRAL, from database inception to January 1st, 2023, to find randomized controlled trials (RCTs) of psychotherapies for GAD. Eight psychotherapies (behaviour therapy, cognitive-behaviour therapy, cognitive restructuring, psychoeducation, psychodynamic therapy, relaxation therapy, supportive psychotherapy, and third-wave CBTs) were compared with each other and two control conditions (treatment as usual, waiting list). We followed Cochrane standards when extracting data and assessing data quality and used PRISMA guidelines for the reporting. We conducted random-effects model pairwise and network meta-analyses. We assessed risk of bias of individual studies through the second version of the Cochrane’s Risk of Bias tool and used the Confidence in Network Meta-Analysis (CINeMA) to rate certainty of evidence for meta-analytical results. Severity of GAD symptoms and acceptability of the psychotherapies were our outcomes of interest.

Results. We analysed data from 66 RCTs. Effect size estimates on data from 5,597 participants suggest third wave cognitive-behavioural therapies (standardized mean differences [SMDs] =-0.78; 95%CI=-1.19 to -0.37; certainty=moderate), cognitive-behavioural therapy (CBT) (SMD=-0.68; 95%CI=-1.05 to -0.32 certainty=moderate), and relaxation therapy (SMD=-0.54; 95%CI=-1.04 to -0.05; certainty=low) reduced generalized anxiety symptoms more than treatment as usual (TAU). Relative risks for all-cause discontinuation signalled no differences compared with TAU for all psychotherapies. When excluding studies at high risk of bias, relaxation therapy lost its superiority over TAU. When considering anxiety severity at three to twelve months after completion of the intervention only CBT remained significantly more efficacious than TAU (SMD=-0.58; 95%CI=-0.93 to -0.23).

Conclusions. Given the evidence for both acute and long-term efficacy, CBT may represent the reasonable first-line psychological treatment for GAD. Third-wave CBT and relaxation therapy have short-term efficacy and may also be offered. Results from this investigation should inform patients, clinicians, and guidelines.