This study aims to investigate the efficacy of three psychotherapeutic programs in group format: Acceptance and Commitment Therapy (ACT), Behavioral Activation (AC) and Transdiagnostic Cognitive Behavioral Therapy (TD-CBT), for the treatment of emotional disorders. Considering the data of the literature and the results of previous research, it is expected that this clinical investigation shows that transdiagnostic interventions that are tested (AC, ACT, TD-CBT) cause clinical changes in the post-treatment. However, it is expected that in post-treatment and in the short and medium-term follow-up, significant differences will be found between the transdiagnostic therapies examined in all outcome criteria variables; and that the greatest effectiveness and effectiveness be achieved in contextual therapies, in particular, in Behavioral Activation therapy. It is expected that the study design will allow obtaining firm evidence of the active therapeutic ingredients from the analysis of the differential efficacy of each of the psychotherapeutic programs. As a final consequence and based on the results and discussion on transdiagnostic conditions and transtherapeutic elements, it is expected to develop a unified treatment protocol (in group format -as an efficient work format and appropriate to the needs of public health services-) to be easily applied in the field of primary care. It could facilitate access to effective treatment of common mental disorders in public health services.

This study aims to investigate the efficacy of three psychotherapeutic programs in group format: Acceptance and Commitment Therapy (ACT), Behavioral Activation (AC) and Transdiagnostic Cognitive Behavioral Therapy (TD-CBT), for the treatment of emotional disorders. Considering the data of the literature and the results of previous research, it is expected that this clinical investigation shows that transdiagnostic interventions that are tested (AC, ACT, TD-CBT) cause clinical changes in the post-treatment. However, it is expected that in post-treatment and in the short and medium term follow-up, significant differences will be found between the transdiagnostic therapies examined in all outcome criteria variables; and that the greatest effectiveness and effectiveness be achieved in contextual therapies, in particular, in Behavioral Activation therapy. It is expected that the study design will allow obtaining firm evidence of the active therapeutic ingredients from the analysis of the differential efficacy of each of the psychotherapeutic programs. As a final consequence and based on the results and discussion on transdiagnostic conditions and transtherapeutic elements, it is expected to develop a unified treatment protocol (in group format -as an efficient work format and appropriate to the needs of public health services-) to be easily applied in the field of primary care. It could facilitate access to effective treatment of common mental disorders in public health services.

The present investigation has as general objectives:

1. Establish the effectiveness, effectiveness and efficiency of Behavioral Activation (AC), Acceptance and Commitment (ACT) and Transdiagnostic Cognitive-Behavioral (TD-CBT) therapy applied in group format for the treatment of emotional disorders in the context of Primary Care.
2. Analyze the differential utility and adequacy of contextual transdiagnostic therapy (AC; ACT) and cognitive behavioral therapy (TD-CBT) according to clinical conditions of the disorder, characteristics of the subjects and of the therapeutic procedure and the transdiagnostic assumptions that define them.
3. Develop a unified treatment protocol for emotional disorders for implementation in primary care.

Specific objectives are:

1. Identify patterns of psychological inflexibility (experiential avoidance; activation and cognitive fusion) and cognitive biases in people with emotional disorders (anxiety and / or depression).
2. To assess the efficacy, effectiveness and efficiency of three transdiagnostic therapies (AC, ACT, and TD-CBT) applied in group format for the treatment of emotional disorders, analyzing the evolution of the outcome criteria defined in relation to emotional state and functionality of the patients assigned to each experimental treatment condition and in relation to a waiting list condition.
3. Assess the adequacy and specificity of AC, ACT and TD-CBT in the treatment of emotional disorders according to different conditions: patient's clinical state, characteristics of the context and the therapeutic procedure defined as outcome criteria variables.
4. Identify the active therapeutic ingredients of the therapies on the results of the efficacy, effectiveness and adequacy of the interventions.
5. Develop a Unified Treatment Protocol to facilitate the implementation of an efficacious and effective intervention of emotional disorders in public health institutions, especially in the context of Primary Care.
6. Maintain a website to disseminate information to general population regarding services provided in the context of this research project and to share experiences with other professionals and researchers.

The sample will be composed by patients who obtain a score that indicates clinically significant symptoms according to the Hospital Anxiety and Depression Scale (HADS, Zigmond and Snaith, 1983). All participants have to sign the informed consent after being informed about the objectives and procedure of the study.

Participants that meet inclusion criteria will be randomly assigned to the experimental and control conditions. The programs will be developed in group format (maximum 8 patients / group) and will be implemented consecutively until reaching the required sample size.

Preselected patients will be interviewed by one of the researchers. The investigator explains the objectives and procedures and then participants sign the informed consent document and answer the Hospital Anxiety and Depression Scale (HADS, Zigmond and Snaith, 1983). When the result indicates clinically significant symptoms, participants will be randomly assigned (according to the table of numbers) to one of the different conditions of the investigation: three experimental (ACT; AC; TD-TCC) and a control (WL). Next, participants will be cited for an individual evaluation session in which the study variables will be explored through clinical interview and scales. After the individual evaluation session, experimental groups will receive 8 group psychotherapy sessions specific to each condition. Then, each patient have follow ups at 3, 6, 9 and 12 months after finishing the therapeutic group.

Wait List group will be evaluated after the same period of time of the experimental groups and with the same procedure. Subsequently, participants will be offered the possibility of receiving the intervention that has been shown to be most effective and / or suitable according to their peculiarities.

Therapy was administered by two licensed clinical psychologists. In order to ensure adhesion of clinical psychologists to therapeutic protocols, the intervention sessions were audio-recorded and weekly supervision sessions by the principal investigator of study were held. In addition, regular peer-to-peer coaching and supervision meetings were held to ensure protocol adherence.

Analysis of data:

The descriptive study of the sample and a study of the equivalence of control and experimental groups (with the relevant statistics according to the type of variable) will be carried out.

The investigators will study patients evolution and compare experimental and control groups in all variables using inferential statistics and evaluate the clinical change at experimental groups. For the statistical analysis a database and the statistical program IBM SPSS will be used.

Inclusion Criteria:

• Anxiety and/or depression (a score above the cutoff point in at least one of HADS subscales)
• Willingness, availability and motivation to participate in a group therapy of 8 sessions.

Exclusion Criteria:

• Being under another psychological treatment
• Physical and / or cognitive deterioration that hinders participation in the therapeutic plan.
• Serious illness that compromises patient's life and / or chronic cancer pain.

All IPD that underlie results in a publication are going to be share on an official data repository (Mendeley Data)