Internet-delivered transdiagnostic and tailored cognitive behavioral therapy for anxiety and depression: a systematic review and meta-analysis of randomized controlled trials

Anxiety and depressive disorders are often comorbid. Transdiagnostic and tailored treatments seem to be promising approaches in dealing with comorbidity. Although several primary studies have examined the effects of Internet-delivered cognitive behavior therapy (iCBT) for anxiety and depression, no meta-analysis including different types of iCBT that address comorbidity has been conducted so far. We conducted systematic searches in databases up to 1 July 2016. Only randomized trials comparing transdiagnostic/tailored iCBT for adult anxiety and/or depression with control groups were included. Nineteen randomized trials with a total of 2952 participants that met inclusion criteria were analyzed. The quality of the studies was high, however the blinding criteria were not fulfilled. The uncontrolled effect size (Hedges’ g) of transdiagnostic/tailored iCBT on anxiety and depression outcomes was large and medium for quality of life. The controlled effect size for iCBT on anxiety and depression outcomes was medium to large (anxiety: g = .82, 95% CI: .58–1.05, depression: g = .79, 95% CI: .59–1.00) and medium on quality of life (g = .56, 95% CI: .37–.73). Heterogeneity was small (quality of life) to moderate (anxiety, depression). There was a large effect on generic outcome measures and a moderate effect on comorbidities. When compared to disorder-specific treatments there were no differences on anxiety and quality of life outcomes, however there were differences in depression outcomes. Transdiagnostic and tailored iCBT are effective interventions for anxiety disorders and depression. Future studies should investigate mechanisms of change and develop outcome measures for these interventions.     

Cognitive-Behavior Therapy (CBT) for Panic Disorder: Relationship of Anxiety and Depression Comorbidity with Treatment Outcome

Research evaluating the relationship of comorbidity to treatment outcome for panic disorder has produced mixed results. The current study examined the relationship of comorbid depression and anxiety to treatment outcome in a large-scale, multi-site clinical trial for cognitive-behavior therapy (CBT) for panic disorder. Comorbidity was associated with more severe panic disorder symptoms, although comorbid diagnoses were not associated with treatment response. Comorbid generalized anxiety disorder (GAD) and major depressive disorder (MDD) were not associated with differential improvement on a measure of panic disorder severity, although only rates of comorbid GAD were significantly lower at posttreatment. Treatment responders showed greater reductions on measures of anxiety and depressive symptoms. These data suggest that comorbid anxiety and depression are not an impediment to treatment response, and successful treatment of panic disorder is associated with reductions of comorbid anxiety and depressive symptoms. Implications for treatment specificity and conceptual understandings of comorbidity are discussed.     

Transdiagnostic internet treatment for anxiety and depression: a randomised controlled trial

Disorder-specific cognitive behavioural therapy programs delivered over the internet (iCBT) with clinician guidance are effective at treating specific anxiety disorders and depression. The present study examined the efficacy of a transdiagnostic iCBT protocol to treat three anxiety disorders and/or depression within the same program (the Wellbeing Program). Seventy-seven individuals with a principal diagnosis of major depression, generalised anxiety disorder, panic disorder, and/or social phobia were randomly assigned to a Treatment or Waitlist Control group. Treatment consisted of CBT-based online educational lessons and homework assignments, weekly email or telephone contact from a clinical psychologist, access to a moderated online discussion forum, and automated emails. Eighty one percent of Treatment group participants completed all 8 lessons within the 10 week program. Post-treatment data were collected from 34/37 Treatment group and 35/37 Control group participants, and 3-month follow-up data were collected from 32/37 Treatment group participants. Relative to Controls, Treatment group participants reported significantly reduced symptoms of anxiety and depression as measured by the Depression Anxiety and Stress Scales-21 item, Patient Health Questionnaire-9 item, and Generalised Anxiety Disorder-7 item scales, with corresponding between-groups effect sizes (Cohen’s d) at post treatment of.56,.58, and.52, respectively. The clinician spent a mean time of 84.76 min (SD = 50.37) per person over the program. Participants rated the procedure as highly acceptable, and gains were sustained at follow-up. These results provide preliminary support for the efficacy of transdiagnostic iCBT in the treatment of anxiety and depressive disorders.     

Diagnostic Comorbidity in Adults With Generalized Anxiety Disorder: Impact of Comorbidity on Psychotherapy Outcome and Impact of Psychotherapy on Comorbid Diagnoses

The current study examined the impact of comorbidity on cognitive and behavioral therapies for generalized anxiety disorder (GAD) as well as the impact of these therapies on diagnoses comorbid to GAD. Seventy-six treatment-seeking adults with principal diagnoses of GAD received 14 sessions of therapy. Most (n = 46; 60.5%) of the sample had at least one comorbid diagnosis. Although the presence of comorbid diagnoses was associated with greater severity of GAD symptoms at pretreatment, greater severity of comorbid major depression, simple phobia, and social phobia was associated with greater change in symptoms of GAD in response to treatment, with no effect on maintenance of gains during a 2-year follow-up. Further, psychotherapy for principal GAD led to a reduction in number of comorbid diagnoses and in severity of social phobia, simple phobia, and major depression at posttreatment. At 2-year follow-up severity of social and simple phobia remained below pretreatment levels, whereas severity of depression was no longer significantly below pretreatment levels. These results suggest that although people with comorbid disorders enter treatment with more severe GAD symptomatology, they demonstrate greater change, and therefore such comorbidity does not diminish the efficacy of cognitive and behavioral therapies for GAD. In addition, the impact of these treatments for GAD may generalize to reduced severity of simple phobia, social phobia, and major depression; however, gains in severity of major depression are not maintained.     

A Transdiagnostic Examination of Intolerance of Uncertainty Across Anxiety and Depressive Disorders

Intolerance of uncertainty (IU) has been identified as a potential maintaining factor for generalised anxiety disorder; however, there is a growing evidence to suggest that IU may contribute to other anxiety and depressive disorders. Moreover, certain components of IU (namely prospective and inhibitory IU) have been shown to be differentially associated with symptoms of emotional disorders. The aim of this study was to determine the extent to which individuals with various anxiety and depressive disorders endorsed IU, firstly as a trait variable (with prospective and inhibitory components) and secondly in reference to regularly occurring, diagnostically relevant situations (situation-specific IU). The degree to which diagnosis predicted IU was examined in a highly comorbid clinical sample (N = 218). Regardless of specific diagnoses, the degree of comorbidity emerged as a significant predictor of prospective IU and situation-specific IU. Conversely, specific diagnoses of social phobia, generalised anxiety disorder, depression, and obsessive compulsive disorder were uniquely related to inhibitory IU. These findings suggest that IU is a transdiagnostic construct and have implications for current diagnosis-specific and transdiagnostic theory and clinical practice.     

The impact of an 8-day intensive treatment for adolescent panic disorder and agoraphobia on comorbid diagnoses

Previous research findings have shown positive effects of cognitive-behavioral therapy for primary anxiety disorders as well as for nonprimary, co-occurring anxiety disorders. In this study, we analyzed data from an existing randomized controlled trial of intensive treatment for panic disorder with or without agoraphobia (PDA) to examine the effects of the treatment on comorbid psychiatric diagnoses. The overall frequency and severity of aggregated comorbid diagnoses decreased in a group of adolescents who received an 8-day treatment for PDA. Results suggest that an 8-day treatment for PDA can alleviate the symptoms of some specific comorbid clinical diagnoses; in particular specific phobias, generalized anxiety disorder, and social phobia. These findings suggest that an intensive treatment for PDA is associated with reductions in comorbid symptoms even though disorders other than PDA are not specific treatment targets.     

An open trial of a transdiagnostic cognitive-behavioral group therapy for anxiety disorder

Transdiagnostic models of anxiety, and cognitive-behavioral treatments based on these models, have been gaining increased attention in recent years. Preliminary efficacy studies generally suggest strong treatment effects, although few of these studies have examined to what extent treatment effects are similar across clients with different anxiety disorders. The purpose of the current study was to examine the efficacy of a 12-week transdiagnostic group cognitive-behavioral therapy for anxiety disorders and compare outcome across diagnoses. Mixed-effect regression modeling of data from 52 participants with anxiety disorders (predominantly panic disorder and social phobia) participating in an open outcome trial indicated that participants tended to improve over treatment, with no differential outcome for any primary or comorbid disorders. The results of this study add to the growing evidence base for transdiagnostic anxiety treatment models and provide preliminary support for the assumption that individuals with different anxiety diagnoses can be treated equally within the same treatment protocol.     

Transdiagnostic Internet treatment for anxiety disorders: A randomized controlled trial

Clinician-guided Internet-based cognitive behavioural therapy (iCBT) programs are clinically effective at treating specific anxiety disorders. The present study examined the efficacy of a transdiagnostic Internet-based cognitive behavioural treatment (iCBT) program to treat more than one anxiety disorder within the same program (the Anxiety Program). Eighty six individuals meeting diagnostic criteria for generalized anxiety disorder (GAD), panic disorder, and/or social phobia were randomly assigned to a treatment group, or to a waitlist control group. Treatment consisted of CBT based online educational lessons and homework assignments, weekly email or telephone contact from a clinical psychologist, access to a moderated online discussion forum, and automated emails. An intention-to-treat model using the baseline-observation-carried-forward principle was employed for data analyses. Seventy-five percent of treatment group participants completed all 6 lessons within the 8 week program. Post-treatment data was collected from 38/40 treatment group and 38/38 control group participants, and 3-month follow-up data was collected from 32/40 treatment group participants. Relative to controls, treatment group participants reported significantly reduced symptoms of anxiety as measured by the Generalized Anxiety Disorder - 7 Item, Social Phobia Screening Questionnaire, and the Panic Disorder Severity Rating Scale - Self Report Scale, but not on the Penn State Worry Questionnaire, with corresponding between-groups effect sizes (Cohen’s d) at post-treatment of 0.78, 0.43, 0.43, and 0.20, respectively. The clinician spent a total mean time of 46 min per person over the program, participants rated the procedure as moderately acceptable, and gains were sustained at follow-up. Modifications to the Anxiety program, based on post-treatment feedback from treatment group participants, were associated with improved outcomes in the control group. These results indicate that transdiagnostic programs for anxiety disorders may be successfully administered via the Internet.     

An open trial of a brief transdiagnostic internet treatment for anxiety and depression

The present study evaluated the efficacy of a brief version of an internet-administered transdiagnostic CBT protocol, the Wellbeing Program (Titov et al., 2011), designed to treat three anxiety disorders and major depression within the same program. This brief version included the same core CBT skills as the original, but condensed the materials from 8 to 5 online lessons, reduced the duration of treatment from 10 to 8 weeks and did not include an online forum. Thirty-two individuals with a principal diagnosis of major depression, generalised anxiety disorder, panic disorder or social phobia received CBT-based online educational lessons, homework assignments, weekly contact from a clinical psychologist and automated emails. Eighty-one percent of participants completed the lessons within the 8 week program. Post-treatment and 3-month follow-up data were collected from 28/32 and 31/32 participants respectively. Participants improved significantly on the Depression Anxiety and Stress Scales – 21 Item, Patient Health Questionnaire – 9 Item, and Generalised Anxiety Disorder – 7 Item scales, with corresponding within-group effect sizes (Cohen’s d) at follow-up of 1.05, .73, and .95, respectively. Participants rated the procedure as highly acceptable with gains of a similar magnitude as those found for the original program, but less time was spent per participant by the clinician in the present trial (mean = 44.61 min, SD = 34.45) compared to the original program (mean = 84.76 min, SD = 50.37). These results provide additional support for the efficacy of transdiagnostic iCBT in the treatment of anxiety and depressive disorders and indicate that a brief version may be of benefit.     

Unified protocol for transdiagnostic treatment of emotional disorders: a randomized controlled trial

This study further evaluates the efficacy of the Unified Protocol for Transdiagnostic Treatment of Emotional Disorders (UP). A diagnostically heterogeneous clinical sample of 37 patients with a principal anxiety disorder diagnosis was enrolled in a randomized controlled trial (RCT) involving up to 18 sessions of treatment and a 6-month follow-up period. Patients were randomly assigned to receive either immediate treatment with the UP (n=26) or delayed treatment, following a 16-week wait-list control period (WLC; n=11). The UP resulted in significant improvement on measures of clinical severity, general symptoms of depression and anxiety, levels of negative and positive affect, and a measure of symptom interference in daily functioning across diagnoses. In comparison, participants in the WLC condition exhibited little to no change following the 16-week wait-list period. The effects of UP treatment were maintained over the 6-month follow-up period. Results from this RCT provide additional evidence for the efficacy of the UP in the treatment of anxiety and comorbid depressive disorders, and provide additional support for a transdiagnostic approach to the treatment of emotional disorders.     

Psychiatric Comorbidity in Children with Autism Spectrum Disorders: A Comparison with Children with ADHD

The present study was conducted with the aim to identify comorbid psychiatric disorders in children with autism spectrum disorders (ASD) (n = 40) and to compare those comorbidity rates to those in children with attention deficit hyperactivity disorder (ADHD) (n = 40). Participants were clinically referred children aged 7–18 years. DSM-IV classifications were used for the primary diagnosis (ASD/ADHD), while comorbid psychiatric disorders were assessed using a structured diagnostic interview, the structured clinical interview for DSM-IV, childhood diagnoses (KID-SCID). Twenty-three children with ASD (57.5 %) had at least one comorbid disorder, whereas 16 children with ADHD (40.0 %) were classified as having at least one comorbid disorder. No group differences were found with respect to this comorbidity rate or for the rate of comorbid externalizing disorders (ODD and/or CD). However, children with ASD had more comorbid internalizing disorders compared to children with ADHD. More specifically, children with ASD had higher rates of anxiety disorders, but not mood disorders. No associations between comorbidity and age or between comorbidity and the intelligence quotient was found. It is important for clinicians to always be aware of, and screen for, comorbidity, and to consider treatment for these comorbid disorders. In addition, research should focus on establishing valid and reliable screening tools as well as effective treatment options for these comorbid disorders.     

A transdiagnostic examination of intolerance of uncertainty across anxiety and depressive disorders

Intolerance of uncertainty (IU) has been identified as a potential maintaining factor for generalised anxiety disorder; however, there is a growing evidence to suggest that IU may contribute to other anxiety and depressive disorders. Moreover, certain components of IU (namely prospective and inhibitory IU) have been shown to be differentially associated with symptoms of emotional disorders. The aim of this study was to determine the extent to which individuals with various anxiety and depressive disorders endorsed IU, firstly as a trait variable (with prospective and inhibitory components) and secondly in reference to regularly occurring, diagnostically relevant situations (situation-specific IU). The degree to which diagnosis predicted IU was examined in a highly comorbid clinical sample (N=218). Regardless of specific diagnoses, the degree of comorbidity emerged as a significant predictor of prospective IU and situation-specific IU. Conversely, specific diagnoses of social phobia, generalised anxiety disorder, depression, and obsessive compulsive disorder were uniquely related to inhibitory IU. These findings suggest that IU is a transdiagnostic construct and have implications for current diagnosis-specific and transdiagnostic theory and clinical practice.     

Impact of cognitive-behavioral therapy for panic disorder on comorbidity: a controlled investigation

This study examined the effects of cognitive-behavioral therapy (CBT) for principal panic disorder with or without agoraphobia, on comorbidity in 30 individuals (16 female). To test the hypothesis that improvements in co-existing conditions were not due to spontaneous fluctuations across time, patients receiving immediate CBT were compared to those assigned to wait list (n = 11). Results indicated clinician-rated severity of comorbid specific phobia declined significantly following immediate CBT compared to no change after wait list. The number of patients without comorbidity of any severity increased after immediate CBT, with no such increase following wait list. However, the groups did not differ in the frequency of additional diagnoses or overall severity of comorbidity. In the total sample, results indicated reductions in comorbidity by 9-month follow-up, with marked declines in the severity of comorbid generalized anxiety disorder (GAD), social and specific phobia. Our findings suggest that targeted CBT for panic disorder has beneficial effects on comorbidity over the longer term and that some of its immediate effects exceed those due to the passage of time alone.     

The frequency of actions and thoughts scale: development and psychometric validation of a measure of adaptive behaviours and cognitions

This paper describes the development and preliminary psychometric evaluation of an instrument that measures the frequency of adaptive behaviours and cognitions related to therapeutic change during cognitive behavioural therapy (CBT), for symptoms of anxiety and depression. Two studies were conducted. In study one, 661 participants completed an online survey with 28 items targeting adaptive behaviours and cognitions. Exploratory factor analysis performed on part of the sample (n = 451) revealed that a four-factor solution ‘characterised’ the data. This led to the development of a 12-item instrument, the Frequency of Actions and Thoughts Scale (FATS). Confirmatory factor analysis was used to confirm the factor structure of the FATS using the remaining sample (n = 210), which revealed an acceptable model fit. In study two, 125 participants with clinically significant symptoms of anxiety, depression, or both were recruited to an Internet-delivered CBT (iCBT) treatment course. Participants completed the FATS and other measures throughout treatment, after treatment, and at three-month follow-up. Correlations and residual change scores of the FATS and its subscales with measures of anxiety, depression, behavioural activation, and CBT-related skills usage supported the construct validity of the FATS. A significant increase in FATS scores over treatment was also observed. The findings provide preliminary support for the psychometric properties of the FATS, which appears to have utility in research investigating mechanisms of change in CBT.     

Comorbidity and the Treatment of Principal Anxiety Disorders in a Naturalistic Sample

This study examined the impact of comorbidity on treatment outcome and the effects of cognitive behavioral therapy (CBT) for anxiety and depressive disorders on comorbid disorders in a naturalistic sample of 150 patients presenting to an anxiety disorders clinic. The following results were observed across principal (i.e., most severe) diagnoses. Patients with comorbid anxiety and depressive disorders presented for treatment with higher severity of their principal disorder than patients without comorbidity. However, the presence of comorbidity did not predict dropout or poor treatment response, and patients demonstrated significant improvement in their principal disorders regardless of comorbidity. The frequency of clinically severe and subclinical (i.e., not severe enough to meet diagnostic criteria) comorbid conditions decreased significantly over the course of treatment. The implication of these findings for the classification and treatment of emotional disorders is discussed.     

The interaction of distress tolerance and intolerance of uncertainty in the prediction of symptom reduction across CBT for social anxiety disorder

Distress tolerance (DT) and intolerance of uncertainty (IU) have been identified as transdiagnostic processes that predict symptom severity across a range of distinct anxiety disorders. However, the joint effect of these two variables on therapeutic outcome has not yet been examined. It is possible that DT and IU may both impact on treatment response to cognitive-behavioural therapy (CBT) in clients with anxiety, as clients with weak DT and strong IU may be less likely to engage in exposure and cognitive restructuring tasks across treatment due to their associated distress. The purpose of this study was to examine the interaction of DT and IU as predictors of post-treatment symptom severity and treatment response to group CBT in participants with primary DSM-IV-TR diagnosed social anxiety disorder (SAD). Participants (N = 95) with SAD completed 12 weeks of manualized group CBT. Results of multilevel longitudinal analysis demonstrated an interaction effect, such that lower DT and higher IU predicted higher SAD symptom severity across the course of therapy. The findings are discussed in terms of clinical implications for the disorder-specific and transdiagnostic treatment of anxiety disorders.     

Psychometric properties of the mini-social phobia inventory (Mini-SPIN) in a large online treatment-seeking sample

The Mini-Social Phobia Inventory (Mini-SPIN) is a brief, three-item measure designed as a screening tool for social anxiety disorder (SAD). This study investigated the Mini-SPIN’s psychometric properties in a series of trials of Internet-delivered treatment. Participants were 993 people seeking Internet-delivered cognitive behavioural therapy for a range of anxiety and mood disorders. Participants completed the Mini-SPIN, and were diagnosed using the Mini International Neuropsychiatric Interview Version 5.0.0 (MINI). They also completed measures of depression, general anxiety, panic, neuroticism and general impairment. The Mini-SPIN’s ability to discriminate between people with and without SAD, within a large sample of people seeking treatment for a range of psychological disorders, was assessed at initial assessment and three-month follow-up. The Mini-SPIN’s criterion group validity, internal consistency, test–retest reliability, construct validity and responsiveness to treatment were also examined. Results demonstrated that the Mini-SPIN has an excellent ability to discriminate between those with and without SAD in a highly comorbid clinical sample, and also has good criterion group validity. The Mini-SPIN also exhibited excellent internal consistency, good test–retest reliability, and was responsive to treatment. These results highlight the Mini-SPIN’s potential as an efficient and reliable measure of SAD in heterogenous populations.     

Metacognitive Therapy in Major Depression: An Open Trial of Comorbid Cases

This open trial investigated the transdiagnostic effects of metacognitive therapy (MCT) in patients with severe major depressive disorder and comorbid psychiatric disorder. Ten patients were treated with MCT over 10 sessions and were assessed with measures of depression, anxiety, rumination, and metacognitions at pre- and posttreatment and at 6 months follow-up. None of the patients were diagnosed as depressed at posttreatment, and of the initial 21 total diagnoses at pretreatment only 3 diagnoses remained at postintervention. The effect sizes were large for symptoms of depression, rumination, and worry. At 6 months follow-up standardized recovery criteria on the BDI showed that 70% were recovered, 20% improved, and 10% unchanged. The results indicate that MCT was associated with high rates of transdiagnostic improvement.     

Rumination and Excessive Reassurance Seeking: Mediators of the Relationship Between Social Anxiety and Depression?

Social anxiety and depression are highly comorbid conditions. Although this has led researchers to suggest that social anxiety may convey risk for depression, few studies have examined mechanisms of comorbidity between these two conditions. The current study tested two mechanisms of comorbidity between symptoms of these disorders: brooding and excessive reassurance seeking. The data were evaluated in an undergraduate sample assessed three times over a 2 month period. Results suggested that brooding mediated the relationship between social anxiety at Time 1 and depression at Time 3, although no evidence was found for excessive reassurance-seeking as a mediator of these two variables. These findings support recent research suggesting that brooding may be a transdiagnostic process. Theoretical and clinical implications are discussed.     

Intolerance of Uncertainty–Focused Treatment for Adolescents With Excessive Worry: A Pilot Feasibility Study

Bouts of excessive worry are common across the lifespan, increasing in frequency and complexity during adolescence and adulthood, and are found in several psychiatric disorders, particularly the anxiety disorders. There are evidence-based treatments for adolescents with anxiety disorders but psychological treatments designed specifically to target excessive worrying in adolescents are rare. Intolerance of uncertainty (IU), a cognitive predisposition described as a fear of the unknown, is highly associated with worry among adolescents. This study investigated the feasibility, acceptability, and preliminary efficacy of IU-focused cognitive behavioral therapy (IU-CBT) for adolescents with excessive worry. Twelve participants (aged 13–17 years) with excessive worry, irrespective of psychiatric diagnosis, were provided weekly face-to-face sessions, primarily including therapist and self-guided exposure to situations involving uncertainty. Sessions were supplemented with an internet-delivered educational program for parents, designed to teach parents about worry, IU and helpful parental behaviors. The main outcome measure was the Penn-State Worry Questionnaire for Children (PSWQ-C). The treatment was well tolerated with no dropouts and families reporting being satisfied with the treatment. Participants were able to grasp the notion of IU and its relationship to worry and avoidance. Significant reductions were observed for self-reported worry, anxiety, depression, IU, and parent-reported worry, as were significant increases in global functioning. Based on a clinician rating, 58.3% were categorized as much or very much improved at posttreatment, rising to 66% at 3-month follow-up. Participants with generalized anxiety disorder (GAD) benefitted more from treatment than those with social anxiety disorder. The findings suggest that this IU-focused psychological intervention is acceptable and feasible to adolescents with excessive worry but may be most effective for those with GAD.