Long-term Effectiveness and Predictors of Transdiagnostic Internet-Delivered Cognitive Behavioral Therapy for Emotional Disorders in Specialized Care: Secondary Analysis of a Randomized Controlled Trial.

BACKGROUND: Transdiagnostic internet-delivered cognitive behavioral therapy (iCBT) for emotional disorders has been shown to be effective in specialized care in the short term. However, less is known about its long-term effects in this specific setting. In addition, predictors of long-term effectiveness may help to identify what treatments are more suitable for certain individuals. OBJECTIVE: This study aimed to analyze the long-term effectiveness of transdiagnostic iCBT compared with that of treatment as usual (TAU) in specialized care and explore predictors of long-term effectiveness. METHODS: Mixed models were performed to analyze the long-term effectiveness and predictors of transdiagnostic iCBT (n=99) versus TAU (n=101) in public specialized mental health care. Outcomes included symptoms of depression and anxiety, health-related quality of life (QoL), behavioral inhibition and behavioral activation, comorbidity, and diagnostic status (ie, loss of principal diagnosis) from baseline to 1-year follow-up. Sociodemographic characteristics (sex, age, and education) and clinical variables (principal diagnosis, comorbidity, and symptom severity at baseline) were selected as predictors of long-term changes. RESULTS: Compared with baseline, transdiagnostic iCBT was more effective than TAU in improving symptoms of depression (b=-4.16, SE 1.80, 95% CI -7.68 to -0.67), health-related QoL (b=7.63, SE 3.41, 95% CI 1.00-14.28), diagnostic status (b=-0.24, SE 0.09, 95% CI -1.00 to -0.15), and comorbidity at 1-year follow-up (b=-0.58, SE 0.22, 95% CI -1.00 to -0.15). From pretreatment assessment to follow-up, anxiety symptoms improved in both transdiagnostic iCBT and TAU groups, but no significant differences were found between the groups. Regarding the predictors of the long-term effectiveness of transdiagnostic iCBT compared with that of TAU, higher health-related QoL at follow-up was predicted by a baseline diagnosis of anxiety, male sex, and the use of psychiatric medication; fewer comorbid disorders at follow-up were predicted by older age and higher baseline scores on health-related QoL; and fewer depressive symptoms at follow-up were predicted by baseline diagnosis of depression. However, this pattern was not observed for baseline anxiety diagnoses and anxiety symptoms. CONCLUSIONS: The results suggest that transdiagnostic iCBT is more effective than TAU to target depressive symptoms among patients with emotional disorders. Anxiety symptoms remained stable at 1-year follow-up, with no differences between the groups. Results on predictors suggest that some groups of patients may obtain specific gains after transdiagnostic iCBT. Specifically, and consistent with the literature, patients with baseline depression improved their depression scores at follow-up. However, this pattern was not found for baseline anxiety disorders. More studies on the predictor role of sociodemographic and clinical variables in long-term outcomes of transdiagnostic iCBT are warranted. Future studies should focus on studying the implementation of transdiagnostic iCBT in Spanish public specialized mental health care. TRIAL REGISTRATION: ClinicalTrials.gov NCT02345668; https://clinicaltrials.gov/ct2/show/NCT02345668.

Effectiveness of the internet-based Unified Protocol transdiagnostic intervention for the treatment of depression, anxiety and related disorders in a primary care setting: a randomized controlled trial.

BACKGROUND: Research has shown that internet-based cognitive behavioural therapy (iCBT) can be a very promising solution to increase access to and the dissemination of evidence-based treatments to all of the population in need. However, iCBT is still underutilized in clinical contexts, such as primary care. In order to achieve the effective implementation of these protocols, more studies in ecological settings are needed. The Unified Protocol (UP) is a transdiagnostic CBT protocol for the treatment of emotional disorders, which includes depression, anxiety and related disorders, that has shown its efficacy across different contexts and populations. An internet-based UP (iUP) programme has recently been developed as an emerging internet-based treatment for emotional disorders. However, the internet-delivered version of the UP (iUP) has not yet been examined empirically. The current project seeks to analyse the effectiveness of the iUP as a treatment for depression, anxiety and related emotional disorders in a primary care public health setting. METHODS: The current study will employ a parallel-group, randomized controlled trial design. Participants will be randomly assigned to (a) the internet-based Unified Protocol (iUP), or (b) enhanced waiting list control (eWLC). Randomization will follow a 2:1 allocation ratio, with sample size calculations suggesting a required sample of 120 (iUP=80; eWLC=40). The Mini-International Neuropsychiatric Interview (M.I.N.I.) will be used for assessing potential participants. The Overall Anxiety Severity and Impairment Scale (OASIS) and the Overall Depression Severity and Impairment Scale (ODSIS) as well as other standardized questionnaires will be used for assessments at baseline, 4 weeks, 8 weeks and 12 weeks from baseline and for the iUP condition during the follow-up. DISCUSSION: Combining the advantages of a transdiagnostic treatment with an online delivery format may have the potential to significantly lower the burden of emotional disorders in public health primary care setting. Anxiety and depression, often comorbid, are the most prevalent psychological disorders in primary care. Because the iUP allows for the treatment of different disorders and comorbidity, this treatment could represent an adequate choice for patients that demand mental health care in a primary care setting. TRIAL REGISTRATION: ISRCTN18056450 https://doi.org/10.1186/ISRCTN18056450 .

Predicting response to transdiagnostic iCBT for emotional disorders from patient and therapist involvement.

BACKGROUND: Transdiagnostic iCBT has been shown to be effective for the treatment of emotional disorders. Less is known about the optimal level of therapist and patient involvement in these interventions. Specific characteristics of Internet-delivered interventions include treatment adherence (e.g., amount of review of the materials) and guidance (e.g., amount of therapist support). Exploring the importance of these elements in treatment outcome may help to maximize the efficiency of Internet-delivered psychological interventions. AIM: In this study, we aimed to analyze the relationship between patient and therapist involvement (i.e., platform usage and amount of therapist guidance) in a sample of patients with emotional disorders who received transdiagnostic iCBT in Spanish public specialized mental healthcare services. METHOD: This is a secondary analysis of a randomized controlled trial. The sample included 63 patients who completed transdiagnostic iCBT for emotional disorders. Platform usage metrics included number of logins into the platform and number of times the participants reviewed the modules. Therapist guidance was measured as the number of support phone calls with a therapist and their total duration (minutes). Logistic regressions and ROC analyses were performed to explore the predictive value of platform usage and therapist guidance in symptom reduction. Clinical outcomes included depressive and anxiety symptoms assessed at baseline and post-intervention. The bivariate relationship between the platform usage and therapist guidance variables was also explored. RESULTS: Overall, platform usage and therapist guidance were not associated with symptom improvement. However, the patient and therapist involvement parameters were intercorrelated. Specifically, the number of calls and their duration were associated with a greater number of logins (r = 0.61; p < .001) and more frequent reviews of the modules (0.46 ≤ r ≤ 0.60; p < .001). Higher baseline depression and anxiety were, respectively, associated with greater improvements in depression (r = -0.37, p = .003) and anxiety after treatment completion (r = -0.48, p < .001). DISCUSSION: The results suggest that there is no reliable cut-off point for platform usage and therapist guidance in predicting optimal symptom reduction. However, significant associations were found between platform usage and guidance variables that warrant additional research. More research on this topic is necessary to further clarify the role of these and other platform usage and guidance variables in Internet-delivered iCBT outcomes.

Blended transdiagnostic group CBT for emotional disorders: A feasibility trial protocol.

INTRODUCTION: Emotional disorders (anxiety and depressive disorders) are a relevant public health concern associated with high prevalence, high costs, and important disability. Therefore, research priorities include designing and testing cost-effective interventions to reach everyone in need. Internet-delivered interventions for emotional disorders are effective and can help to disseminate and implement evidence-based treatments. However, although these treatments are generally effective, not all patients benefit from this treatment format equally. Blended treatments are a new form of intervention that combines the strengths of face-to-face and Internet approaches. Nevertheless, research on blended interventions has focused primarily on individual therapy, and less attention has been paid to the potential of using this format in group psychotherapy. This study aims to analyze the feasibility of blended transdiagnostic group CBT for emotional disorders. The current article describes the study protocol for this trial. METHOD AND ANALYSIS: A one-armed pilot trial will be conducted. Participants will be 30 adults suffering from DSM-5 anxiety and/or depressive disorders. The treatment consists of a blended transdiagnostic group intervention delivered during a period of 24 weeks. Groups of 6 to 10 patients will attend a total of eight 2-hour, face-to-face sessions, alternated with the use of an online platform where they will find the contents of the treatment protocol. The intervention has four core components: present-focused awareness, cognitive flexibility, identification and modification of behavioral and cognitive patterns of emotional avoidance, and interoceptive and situational exposure. These components are delivered in 16 modules. Assessments will be performed at baseline, during the treatment, at post-treatment, and at 3-month follow-up. Clinical and treatment acceptability outcomes will be included. Quantitative and qualitative data (participants' views about blended group psychotherapy) will be analyzed. ETHICS AND DISSEMINATION: The trial has received ethical approval from the Ethics Committee of Universitat Jaume I (September 2019) and will be conducted in accordance with the study protocol, the Declaration of Helsinki, and good clinical practice. The results of this study will be disseminated by presentation at conferences and will be submitted for publication in a peer-reviewed journal. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04008576. Registered 05 July 2019, https://clinicaltrials.gov/ct2/show/NCT04008576.

Negative and Positive Affect Regulation in a Transdiagnostic Internet-Based Protocol for Emotional Disorders: Randomized Controlled Trial.

BACKGROUND: Emotional disorders (EDs) are among the most prevalent mental disorders. Existing evidence-based psychological treatments are not sufficient to reduce the disease burden of mental disorders. It is therefore essential to implement innovative solutions to achieve a successful dissemination of psychological treatment protocols, and in this regard, the use of information and communication technologies such as the internet can be very useful. Furthermore, the literature suggests that not everyone with an ED receives the appropriate treatment. This situation has led to the development of new intervention proposals based on the transdiagnostic perspective, which attempts to address the underlying processes common to EDs. Most of these transdiagnostic interventions focus primarily on downregulating negative affectivity (NA), and less attention has been paid to strengths and the upregulation of positive affectivity, despite its importance for well-being and mental health. OBJECTIVE: This study aims to evaluate the efficacy of a transdiagnostic internet-based treatment for EDs in a community sample. METHODS: A 3-armed randomized controlled trial was conducted. A total of 216 participants were randomly assigned to a transdiagnostic internet-based protocol (TIBP), a TIBP+ positive affect (PA) component, or a waiting list (WL) control group. The treatment protocol contained core components mainly addressed to downregulate NA (ie, present-focused emotional awareness and acceptance, cognitive flexibility, behavioral and emotional avoidance patterns, and interoceptive and situational exposure) as well as a PA regulation component to promote psychological strengths and enhance well-being. Data on depression, anxiety, quality of life, neuroticism and extraversion, and PA/NA before and after treatment were analyzed. Expectations and opinions of treatment were also analyzed. RESULTS: Within-group comparisons indicated significant pre-post reductions in the two experimental conditions. In the TIBP+PA condition, the effect sizes were large for all primary outcomes (d=1.42, Beck Depression Inventory [BDI-II]; d=0.91, Beck Anxiety Inventory [BAI]; d=1.27, Positive and Negative Affect Schedule-Positive [PANAS-P]; d=1.26, Positive and Negative Affect Schedule-Negative [PANAS-N]), whereas the TIBP condition yielded large effect sizes for BDI-II (d=1.19) and PANAS-N (d=1.28) and medium effect sizes for BAI (d=0.63) and PANAS-P (d=0.69). Between-group comparisons revealed that participants who received one of the two active treatments scored better at posttreatment than WL participants. Although there were no statistically significant differences between the two intervention groups on the PA measure, effect sizes were consistently larger in the TIBP+PA condition than in the standard transdiagnostic protocol. CONCLUSIONS: Overall, the findings indicate that EDs can be effectively treated with a transdiagnostic intervention via the internet, as significant improvements in depression, anxiety, and quality of life measures were observed. Regarding PA measures, promising effects were found, but more research is needed to study the role of PA as a therapeutic component. TRIAL REGISTRATION: ClinicalTrials.gov NCT02578758; https://clinicaltrials.gov/ct2/show/NCT02578758. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1186/s12888-017-1297-z.

Effectiveness of a Transdiagnostic Guided Internet-Delivered Protocol for Emotional Disorders Versus Treatment as Usual in Specialized Care: Randomized Controlled Trial.

BACKGROUND: Anxiety disorders and depression (emotional disorders) are highly prevalent mental disorders. Extensive empirical evidence supports the efficacy of cognitive behavioral therapy (CBT) for the treatment of these disorders. However, there are still some barriers related to their dissemination and implementation, which make it difficult for patients to receive these treatments, especially in public health care settings where resources are limited. Recent advances in improving CBT dissemination encompass different perspectives. One is the transdiagnostic approach, which offers treatment protocols that can be used for a range of emotional disorders. Another approach is the use of the internet to reach a larger number of people who could benefit from CBT. OBJECTIVE: This study aimed to analyze the effectiveness and acceptability of a transdiagnostic internet-delivered protocol (EmotionRegulation) with human and automated guidance in patients from public specialized mental health care settings. METHODS: A 2-armed randomized controlled trial (RCT) was conducted to compare the effectiveness of EmotionRegulation with treatment as usual (TAU) in specialized mental health care. In all, 214 participants were randomly assigned to receive either EmotionRegulation (n=106) or TAU (n=108). Measurement assessments were conducted at pre- and postintervention and at a 3-month follow-up. RESULTS: The results revealed the superiority of EmotionRegulation over TAU on measures of depression (d=0.41), anxiety (d=0.35), and health-related quality of life (d=-0.45) at posttreatment, and these gains were maintained at the 3-month follow-up. Furthermore, the results for expectations and opinions showed that EmotionRegulation was well accepted by participants. CONCLUSIONS: EmotionRegulation was more effective than TAU for the treatment of emotional disorders in the Spanish public mental health system. The implications of this RCT, limitations, and suggestions for future research are discussed. TRIAL REGISTRATION: ClinicalTrials.gov NCT02345668; https://clinicaltrials.gov/ct2/show/NCT02345668.

Positive and Negative Affect Schedule (PANAS): psychometric properties of the online Spanish version in a clinical sample with emotional disorders.

BACKGROUND: The Positive and Negative Affect Schedule (PANAS) is the most widely and frequently used scale to assess positive and negative affect. The PANAS has been validated in several languages, and it has shown excellent psychometric properties in the general population and some clinical samples, such as forensic samples, substance users, and adult women with fibromyalgia. Nevertheless, the psychometric properties of the scale have not yet been examined in clinical samples with anxiety, depressive, and adjustment disorders. In addition, the proliferation of Internet-based treatments has led to the development of a wide range of assessments conducted online with digital versions of pen and paper self-report questionnaires. However, no validations have been carried out to analyze the psychometric properties of the online version of the PANAS. The present study investigates the psychometric properties of the online Spanish version of the PANAS in a clinical sample of individuals with emotional disorders. METHODS: The sample was composed of 595 Spanish adult volunteers with a diagnosis of depressive disorder (n = 237), anxiety disorder (n = 284), or adjustment disorder (n = 74). Factor structure, construct validity, internal consistency, and sensitivity to change were analyzed. RESULTS: Confirmatory factor analysis yielded a latent structure of two independent factors, consistent with previous validations of the instrument. The analyses showed adequate convergent and discriminant validity, good internal consistency as well as sensitivity to change. CONCLUSIONS: Overall, the results obtained in this study show that the online version of the PANAS has adequate psychometric properties for the assessment of positive and negative affect in a Spanish clinical population.

Capturing the Severity and Impairment Associated With Depression: The Overall Depression Severity and Impairment Scale (ODSIS) Validation in a Spanish Clinical Sample.

Background: The Overall Depression Severity and Impairment Scale (ODSIS) is a self-report scale designed to evaluate the severity and functional impairment associated with depression. Objective: This study evaluated the psychometric properties of the online version of the ODSIS in Spanish outpatients with depression and anxiety disorders. Method: Patients with a main diagnosis of a depressive (n = 283) or anxiety disorder (n = 191) and a mean age of 38.15 (SD = 12.06) were evaluated with a clinical diagnostic interview and measures assessing depression, anxiety, positive and negative affect, and quality of life. Factorial structure, internal consistency, convergent, and discriminant validity and cutoff scores were analyzed. Results: Consistent with previous validations of the instrument, Confirmatory Factor Analysis showed a unidimensional factor structure. Furthermore, the results obtained supported the internal consistency and construct validity of the ODSIS scores. A score of 5 was found to meet the criteria used in this study for the optimal cutoff score. Conclusion: The results obtained in this study show that the Spanish version of the ODSIS delivered online is an adequate tool to assess the depression-related severity and impairment in a brief and easy fashion.

Upregulating Positive Affectivity in the Transdiagnostic Treatment of Emotional Disorders: A Randomized Pilot Study.

Transdiagnostic cognitive-behavioral therapy for emotional disorders (ED) has proven to be effective. However, current transdiagnostic treatment protocols address only the regulation of negative affectivity, and they do not include treatment components to more directly target the regulation of positive affectivity. In this study, we propose to evaluate the preliminary efficacy and acceptability of a transdiagnostic treatment protocol for ED that includes, as an innovative feature, a specific treatment component to directly upregulate positive affectivity based on positive psychology interventions. A total of 24 participants were randomized to either a transdiagnostic treatment protocol ( n = 12) or a transdiagnostic treatment protocol with an additional component designed to regulate positive affectivity ( n = 12). Participants completed measures of anxiety, depression, positive and negative affectivity, and quality of life, as well as treatment acceptability at pre- and posttreatment and at the 3-month follow-up. Both interventions led to improvements in all measures at posttreatment, and these outcomes were maintained at the 3-month follow-up, with large effect sizes for all measures. The effect sizes for positive affect were larger in the condition that included the component to upregulate positive affectivity. Attrition rate was low, and both treatment protocols were well accepted by participants. The results obtained in this study indicate the feasibility of testing the treatment protocol in a larger, randomized, controlled trial, and they suggest the potential of including treatment components for directly upregulating positive affectivity in future research on transdiagnostic treatment protocols for ED.

A brief online transdiagnostic measure: Psychometric properties of the Overall Anxiety Severity and Impairment Scale (OASIS) among Spanish patients with emotional disorders.

The Overall Anxiety Severity and Impairment Scale (OASIS) is a self-report questionnaire designed to evaluate the severity and functional impairment associated with anxiety. Given its transdiagnostic nature, it can be used indistinctly across anxiety and depressive disorders. In this study, the psychometric properties of the online version of the OASIS were evaluated in a Spanish clinical sample with emotional disorders. Patients (n = 583) with anxiety (n = 250) and depression (n = 333) with a mean age of 37.21 (SD = 12.22), underwent a diagnostic interview and questionnaires assessing anxiety, depression, positive and negative affect, and quality of life. Factorial structure, internal consistency, convergent and discriminant validity, cutoff scores, and sensitivity to change were analyzed. Confirmatory Factor Analysis yielded a unidimensional factor structure, consistent with previous validations of the instrument. The analyses showed good internal consistency and adequate convergent and discriminant validity, as well as sensitivity to change. A cutoff score of 7.5 was found to meet the criteria used in this study to select the optimal cutoff point. Overall, in this study, the psychometric properties of the online version of the OASIS were found to be appropriate. The brevity and ease of use of the OASIS support its adequacy as a valid measure of anxiety severity and impairment in Spanish clinical samples with anxiety and depression.

Comorbidity and diagnosis distribution in transdiagnostic treatments for emotional disorders: A systematic review of randomized controlled trials.

The advantages of transdiagnostic protocols for emotional disorders (ED) (anxiety and depression) include the ability to treat multiple psychological disorders using the same treatment protocol, and the capacity to better address comorbidity. Comorbidity in ED has been associated with higher rates of severity, functional impairment, and chronicity. However, no attempts have been made in the literature to systematically review whether these studies include assessments to evaluate the treatment response in comorbid diagnoses, in addition to the principal diagnosis. Moreover, transdiagnostic treatments have been developed for a range of ED, but to date no study has analyzed the real distribution of diagnoses in these studies. The current study aimed to analyze: a) whether treatment response in comorbidity is evaluated in transdiagnostic treatments for ED; b) what diagnoses are targeted in transdiagnostic treatments for ED; and c) the real distribution of the diagnoses at baseline in these studies. A systematic search of the literature was conducted in PsycINFO, PubMed, EMBASE, and the Cochrane Library. Fifty-two randomized controlled trials were identified, with a total of 7007 adult participants. The results showed that, although most of the studies reported data on comorbidity at baseline, only 40% of them examined the effects of the intervention on the comorbid disorders. The most commonly targeted diagnoses in transdiagnostic protocols were panic/agoraphobia, generalized anxiety, social anxiety, and depression. Other disorders, such as obsessive-compulsive disorder, posttraumatic stress disorder, and anxiety/depression not otherwise specified, were marginally included in these studies. Regarding the distribution of diagnoses at baseline, generalized anxiety, panic/agoraphobia, social anxiety, and depression were the most frequently observed, whereas depression not otherwise specified was the least represented. The results highlight the importance of assessing comorbidity in addition to the principal diagnoses in transdiagnostic treatments, in order to draw conclusions about the true potential of these interventions to improve comorbid symptoms. Implications of the current study and directions for future research are discussed.

Efficacy of a Transdiagnostic internet-based treatment for emotional disorders with a specific component to address positive affect: Study protocol for a randomized controlled trial.

BACKGROUND: Emotional disorders (ED) are among the most prevalent mental disorders. However, less than 50% of people suffering from ED receive the appropriate treatment. This situation has led to the development of new intervention proposals based on the transdiagnostic perspective, which tries to address the underlying processes common to ED. Most of these programs focus primarily on down-regulating negative affectivity, rather than increasing strengths and up-regulating positive affectivity. The data suggest the existence of disturbances in positive affectivity in these disorders, and so new interventions focusing on these problems are greatly needed. It is also essential to provide assistance to all the people in need. Information and Communication Technologies can be very useful. This study aims to evaluate the efficacy of a transdiagnostic Internet-based treatment for ED in a community sample. The protocol includes traditional CBT components, as well as a specific component to address positive affect. We intend to test this protocol, including this specific component or not, versus a waiting list control group. Moreover, we aim to test the differential effect of this specific component, and study the effectiveness (in terms of patients' acceptance) of using a self-applied Internet-based program. This paper presents the study protocol. METHODS: The study is a randomized controlled trial. 207 participants will be randomly assigned to: a)Transdiagnostic Internet-based protocol (TIBP), b)Transdiagnostic Internet-based protocol + positive affect component (TIBP + PA), or c)a Waiting List control group (WL). Primary outcomes measures will be the BDI-II, the BAI, and the PANAS. Secondary outcomes will include diagnosis-specific measures of the principal disorder. Participants' treatment acceptance will also be measured. Participants will be assessed at pre-, post-treatment, and 3- and 12- month follow-ups. The data will be analyzed based on the Intention-to-treat principle. Per protocol analyses will also be performed. DISCUSSION: To the best of our knowledge, this is the first study of a transdiagnostic Internet-based treatment for ED with a specific component to up-regulate positive affectivity. This intervention could contribute to improve the efficiency and effectiveness of current treatment programs for ED, promote the dissemination of EBTs, and help to decrease the high prevalence of ED. TRIAL REGISTRATION: ClinicalTrial.gov: NCT02578758 . Registered 15 October 2015.

Effectiveness of a transdiagnostic internet-based protocol for the treatment of emotional disorders versus treatment as usual in specialized care: study protocol for a randomized controlled trial.

BACKGROUND: Emotional disorders (depression and anxiety disorders) are highly prevalent mental health problems. Although evidence showing the effectiveness of disorder-specific treatments exists, high comorbidity rates among emotional disorders limit the utility of these protocols. This has led some researchers to focus their interest on transdiagnostic interventions, a treatment perspective that might be more widely effective across these disorders. Also, the current way of delivering treatments makes it difficult provide assistance to all of the population in need. The use of the Internet in the delivery of evidence-based treatments may help to disseminate treatments among the population. In this study, we aim to test the effectiveness of EmotionRegulation, a new transdiagnostic Internet-based protocol for unipolar mood disorders, five anxiety disorders (panic disorder, agoraphobia, social anxiety disorder, generalized anxiety disorder and anxiety disorder not otherwise specified), and obsessive-compulsive disorder in comparison to treatment as usual as provided in Spanish public specialized mental health care. We will also study its potential impact on basic temperament dimensions (neuroticism/behavioral inhibition and extraversion/behavioral activation). Expectations and opinions of patients about this protocol will also be studied. METHODS/DESIGN: The study is a randomized controlled trial. 200 participants recruited in specialized care will be allocated to one of two treatment conditions: a) EmotionRegulation or b) treatment as usual. Primary outcome measures will be the BAI and the BDI-II. Secondary outcomes will include a specific measure of the principal disorder, and measures of neuroticism/behavioral inhibition and extraversion/behavioral activation. Patients will be assessed at baseline, post-treatment, and 3- and 12-month follow-ups. Intention to treat and per protocol analyses will be performed. DISCUSSION: Although the effectiveness of face-to-face transdiagnostic protocols has been investigated in previous studies, the number of published transdiagnostic Internet-based programs is still quite low. To our knowledge, this is the first randomized controlled trial studying the effectiveness of a transdiagnostic Internet-based treatment for several emotional disorders in public specialized care. Combining both a transdiagnostic approach with an Internet-based therapy format may help to decrease the burden of mental disorders, reducing the difficulties associated with disorder-specific treatments and facilitating access to people in need of treatment. Strengths and limitations are discussed. TRIAL REGISTRATION: ClinicalTrials.gov NCT02345668 . Registered 27 July 2015.