| 1. |
- Bezdjian, Serena, et al.
(författare)
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Genetic and environmental influences on impulsivity : a meta-analysis of twin, family and adoption studies
- 2011
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Ingår i: Clinical Psychology Review. - : Elsevier BV. - 0272-7358 .- 1873-7811. ; 31:7, s. 1209-1223
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Forskningsöversikt (refereegranskat)abstract
- A meta-analysis of twin, family and adoption studies was conducted to estimate the magnitude of genetic and environmental influences on impulsivity. The best fitting model for 41 key studies (58 independent samples from 14. month old infants to adults; N = 27,147) included equal proportions of variance due to genetic (0.50) and non-shared environmental (0.50) influences, with genetic effects being both additive (0.38) and non-additive (0.12). Shared environmental effects were unimportant in explaining individual differences in impulsivity. Age, sex, and study design (twin vs. adoption) were all significant moderators of the magnitude of genetic and environmental influences on impulsivity. The relative contribution of genetic effects (broad sense heritability) and unique environmental effects were also found to be important throughout development from childhood to adulthood. Total genetic effects were found to be important for all ages, but appeared to be strongest in children. Analyses also demonstrated that genetic effects appeared to be stronger in males than in females. Method of assessment (laboratory tasks vs. questionnaires), however, was not a significant moderator of the genetic and environmental influences on impulsivity. These results provide a structured synthesis of existing behavior genetic studies on impulsivity by providing a clearer understanding of the relative genetic and environmental contributions in impulsive traits through various stages of development.
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| 2. |
- Cuijpers, Pim, et al.
(författare)
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Psychological treatment of depression in inpatients: A systematic review and meta-analysis
- 2011
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Ingår i: CLINICAL PSYCHOLOGY REVIEW. - : PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND. - 0272-7358 .- 1873-7811. ; 31:3, s. 353-360
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Forskningsöversikt (refereegranskat)abstract
- Research on psychological treatment of depression in inpatients is not conclusive, with some studies finding clear positive effects and other studies finding no significant benefit compared to usual care or structured pharmacotherapy. The results of a meta-analysis investigating how effective psychological treatment is for depressed inpatients are presented. A systematic search in bibliographical databases resulted in 12 studies with a total of 570 respondents. This set of studies had sufficient statistical power to detect small effect sizes. Psychological treatments had a small (g = 0.29), but statistically significant additional effect on depression compared to usual care and structured pharmacological treatments only. This corresponded with a numbers-needed-to-be-treated of 6.17. Heterogeneity was zero in most analyses, and not significant in all analyses. There was no indication for significant publication bias. Effects were not associated with characteristics of the population, the interventions and the design of the studies. Although the number of studies was small, and the quality of many studies was not optimal, it seems safe to conclude that psychological treatments have a small but robust effect on depression in depressed inpatients. More high-quality research is needed to verify these results.
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| 3. |
- Cuijpers, Pim, et al.
(författare)
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Psychological treatment of generalized anxiety disorder : A meta-analysis
- 2014
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Ingår i: Clinical Psychology Review. - : Elsevier. - 0272-7358 .- 1873-7811. ; 34:2, s. 130-140
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Tidskriftsartikel (refereegranskat)abstract
- Recent years have seen a near-doubling of the number of studies examining the effects of psychotherapies for generalized anxiety disorder (GAD) in adults. The present article integrates this new evidence with the older literature through a quantitative meta-analysis. A total of 41 studies (with 2132 patients meeting diagnostic criteria for GAD) were identified through systematic searches in bibliographical databases, and were included in the meta-analysis. Most studies examined the effects of cognitive behavior therapy (CBT). The majority of studies used waiting lists as control condition. The pooled effect of the 38 comparisons (from 28 studies) of psychotherapy versus a control group was large (g=0.84; 95% CI: 0.71-0.97) with low to moderate heterogeneity. The effects based on self-report measures were somewhat lower than those based on clinician-rated instruments. The effects on depression were also large (g=0.71; 95% CI: 0.59-0.82). There were some indications for publication bias. The number of studies comparing CBT with other psychotherapies (e.g., applied relaxation) or pharmacotherapy was too small to draw conclusions about comparative effectiveness or the long-term effects. There were some indications that CBT was also effective at follow-up and that CBT was more effective than applied relaxation in the longer term.
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| 4. |
- Cuijpers, Pim, et al.
(författare)
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Psychotherapy for chronic major depression and dysthymia: A meta-analysis
- 2010
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Ingår i: Clinical Psychology Review. - : Elsevier BV. - 0272-7358 .- 1873-7811. ; 30:1, s. 51-62
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Forskningsöversikt (refereegranskat)abstract
- Although several studies have examined the effects of psychotherapy on chronic depression and dysthymia, no meta-analysis has been conducted to integrate results of these studies. We conducted a meta-analysis of 16 randomized trials examining the effects of psychotherapy on chronic depression and dysthymia. We found that psychotherapy had a small but significant effect (d=0.23) on depression when compared to control groups. Psychotherapy was significantly less effective than pharmacotherapy in direct comparisons (d=-031), especially SSRIs, but that this finding was wholly attributable to dysthymic patients (the studies examining dysthymia patients were the same studies that examined SSRIs). Combined treatment was more effective than pharmacotherapy alone (d=0.23) but even more so with respect to psychotherapy alone (d=0.45), although again this difference may have reflected the greater proportion of dysthymic samples in the latter. No significant differences were found in drop-out rates between psychotherapy and the other conditions. We found indications that at least 18 treatment sessions are needed to realize optimal effects of psychotherapy. We conclude that psychotherapy is effective in the treatment of chronic depression and dysthymia but probably not as effective as pharmacotherapy (particularly the SSRIs).
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| 5. |
- Cuijpers, Pim, et al.
(författare)
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Self-reported versus clinician-rated symptoms of depression as outcome measures in psychotherapy research on depression: A meta-analysis
- 2010
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Ingår i: CLINICAL PSYCHOLOGY REVIEW. - : Elsevier Science B.V., Amsterdam.. - 0272-7358 .- 1873-7811. ; 30:6, s. 768-778
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Forskningsöversikt (refereegranskat)abstract
- It is not well-known whether self-report measures and clinician-rated instruments for depression result in comparable outcomes in research on psychotherapy. We conducted a meta-analysis in which randomized controlled trials were included examining the effects of psychotherapy for adult depression. Only studies were included in which both a self-report and a clinician-rated instrument were used. We calculated the effect size (Hedges g) based on the self-report measures, the effect size based on the clinician-rated instruments, and the difference between these two effect sizes (Delta g). A total of 48 studies including a total of 2462 participants was included in the meta-analysis. The differential effect size was Delta g=0.20 (95% CI: 0.10-0.30), indicating that clinician-rated instruments resulted in a significantly higher effect size than self-report instruments from the same studies. When we limited the effect size analysis to those studies comparing the HRSD with the BDI, the differential effect was somewhat smaller, but still statistically significant (Delta g=0.15; 95% CI: 0.03-0.27). This meta-analysis has made it clear that clinician-rated and self-report measures of improvement following psychotherapy for depression are not equivalent. Different symptoms may be more suitable for self-report or ratings by clinicians and in clinical trials it is probably best to include both.
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| 6. |
- Cuijpers, Pim, et al.
(författare)
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The efficacy of non-directive supportive therapy for adult depression : A meta-analysis
- 2012
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Ingår i: Clinical Psychology Review. - : Elsevier. - 0272-7358 .- 1873-7811. ; 32:4, s. 280-291
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Tidskriftsartikel (refereegranskat)abstract
- The effects of non-directive supportive therapy (NDST) for adult depression have been examined in a considerable number of studies, but no meta-analysis of these studies has been conducted. We selected 31 studies on NDST from a comprehensive database of trials, examining psychotherapies for adult depression, and conducted meta-analyses in which NDST was compared with control groups, other psychotherapies and pharmacotherapy. We found that NDST is effective in the treatment of depression in adults (g=0.58; 95% CI: 0.45-0.72). NDST was less effective than other psychological treatments (differential effect size g=-0.20; 95% CI: -0.32 to -0.08, p<0.01), but these differences were no longer present after controlling for researcher allegiance. We estimated that extra-therapeutic factors (those processes operating in waiting-list and care-as-usual controls) were responsible for 33.3% of the overall improvement, non-specific factors (the effects of NDST compared with control groups) for 49.6%, and specific factors (the effects of NDST compared with other therapies) for 17.1%. NDST has a considerable effect on symptoms of depression. Most of the effect of therapy for adult depression is realized by non-specific factors, and our results suggest that the contribution of specific effects is limited at best.
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| 7. |
- Farrand, Paul, et al.
(författare)
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Impact of support on the effectiveness of written cognitive behavioural self-help : a systematic review and meta-analysis of randomised controlled trials
- 2013
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Ingår i: Clinical Psychology Review. - : Elsevier. - 0272-7358 .- 1873-7811. ; 33:1, s. 182-195
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Tidskriftsartikel (refereegranskat)abstract
- Cognitive behavioural therapy self-help is an effective intervention for a range of common mental health difficulties. However the extent to which effectiveness may vary by type of support--guided, minimal contact, self-administered--has not been extensively considered. This review identifies the impact of support on the effectiveness of written cognitive behavioural self-help and further explores the extent to which effectiveness varies across mental health condition by type of support provided. Randomised controlled trials were identified by searching relevant bibliographic databases, clinical trials registers, conference proceedings and expert contact. 38 studies were included in the meta-analysis yielding a statistically significant overall mean effect size (Hedges' g=-0.49). Overall effect size did not significantly differ by type of support (Q=0.85, df=2, p=0.65) (guided: Hedges' g=-0.53; minimal contact: Hedges' g=-0.55; self-administered: Hedges' g=-0.42). For guided and self-administered types of support, planned comparisons revealed a trend for effect size to vary by mental health condition and for guided CBT self-help the modality of support was significant (Q=6.32, df=2, p=0.04), with the largest effect size associated with telephone delivery (Hedges' g=-0.91). Additional moderator analysis was undertaken for depression given the number of available studies. Regardless of higher baseline levels of severity the effect size for minimal contact was greater than for guided support. Greater consideration should be given to the potential that type of support may be related to the effectiveness of written cognitive behavioural self-help and that this may vary across mental health condition. Findings from this systematic review make several recommendations to inform future research.
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| 8. |
- Haug, Thomas, et al.
(författare)
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Self-help treatment of anxiety disorders : A meta-analysis and meta-regression of effects and potential moderators
- 2012
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Ingår i: Clinical Psychology Review. - : Elsevier BV. - 0272-7358 .- 1873-7811. ; 32:5, s. 425-445
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Forskningsöversikt (refereegranskat)abstract
- Self-help treatments have the potential to increase the availability and affordability of evidence-based treatments for anxiety disorders. Although promising, previous research results are heterogeneous, indicating a need to identify factors that moderate treatment outcome. The present article reviews the literature on self-help treatment for anxiety disorders among adults, with a total sample of 56 articles with 82 comparisons. When self-help treatment was compared to wait-list or placebo, a meta-analysis indicated a moderate to large effect size (g = 0.78). When self-help treatment was compared to face-to-face treatment, results indicated a small effect that favored the latter (g = -0.20). When self-help was compared to wait-list or placebo, subgroup analyses indicated that self-help treatment format, primary anxiety diagnosis and procedures for recruitment of subjects were related to treatment outcome in bivariate analyses, but only recruitment procedures remained significant in a multiple meta-regression analysis. When self-help was compared to face-to-face treatment, a multiple meta-regression indicated that the type of comparison group, treatment format and gender were significantly related to outcome. We conclude that self-help is effective in the treatment of anxiety disorders, and should be offered as part of stepped care treatment models in community services. Implications of the results and future directions are discussed.
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| 9. |
- Hesser, Hugo, 1982-, et al.
(författare)
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A systematic review and meta-analysis of randomized controlled trials of cognitive-behavioral therapy for tinnitus distress
- 2011
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Ingår i: Clinical Psychology Review. - : Elsevier. - 0272-7358 .- 1873-7811. ; 31:4, s. 545-553
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Forskningsöversikt (refereegranskat)abstract
- Tinnitus is defined as a sound in the ear(s) and/or head without external origin and is a serious health concern for millions worldwide. The aim of the present study was to determine whether Cognitive Behavior Therapy (CBT) is effective in reducing distress associated with tinnitus. Randomized, controlled trials that assessed the efficacy of CBT for tinnitus-related distress in adults were identified by searching electronic databases (PsychINFO, PubMed, the Cochrane Library), and by manual searches. Fifteen studies (total of 1091 participants) were included in the meta-analysis. CBT compared with a passive and active control at post-assessment yielded statistically significant mean effect sizes for tinnitus-specific measures (Hedges's g = 0.70. and Hedges's g = 0.44, respectively). The average weighted pre-to-follow-up effect size for the CBT group suggested that these effects were maintained over time. Smaller but yet statistically significant effects of CBT were found for mood outcome measures. Characteristics of the studies were unrelated to effect sizes. Methodological rigor, publication bias, and a series of sensitivity analyses did not influence the findings. The results suggest that CBT is an effective treatment of tinnitus distress. However, caution is warranted given that few large-scale, well-controlled trials were identified.
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| 10. |
- Holmes, Emily A., et al.
(författare)
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Mental imagery in emotion and emotional disorders
- 2010
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Ingår i: Clinical Psychology Review. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0272-7358 .- 1873-7811. ; 30:3, s. 349-362
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Forskningsöversikt (refereegranskat)abstract
- Mental imagery has been considered relevant to psychopathology due to its supposed special relationship with emotion, although evidence for this assumption has been conspicuously lacking. The present review is divided into four main sections: (1) First, we review evidence that imagery can evoke emotion in at least three ways: a direct influence on emotional systems in the brain that are responsive to sensory signals; overlap between processes involved in mental imagery and perception which can lead to responding "as if' to real emotion-arousing events; and the capacity of images to make contact with memories for emotional episodes in the past. (2) Second, we describe new evidence confirming that imagery does indeed evoke greater emotional responses than verbal representation, although the extent of emotional response depends on the image perspective adopted. (3) Third, a heuristic model is presented that contrasts the generation of language-based representations with imagery and offers an account of their differing effects on emotion, beliefs and behavior. (4) Finally, based on the foregoing review, we discuss the role of imagery in maintaining emotional disorders, and its uses in psychological treatment. (C) 2010 Elsevier Ltd. All rights reserved.
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