Here is the design of a clinical trial:

Official Title: Mindfulness-based and Compassion-based Interventions in Anxious-Depressive Symptomatology in Mental Health Services: A Randomized Controlled Trial

Included conditions:
- Anxious-Depressive

Study Armgroups:
- {'label': 'MBSR+TAU', 'type': 'EXPERIMENTAL', 'description': 'Mindfulness based Intervention (MBSR) + Usual specialized treatment in mental health. MBSR consists of 8 weekly groupal sessions of 150 minutes/session (10-16 people). Written material and sound recordings will be offered as support elements. The estimated duration of the program is two months.', 'interventionNames': ['Behavioral: Mindfulness based Intervention']}
- {'label': 'ABCT+TAU', 'type': 'EXPERIMENTAL', 'description': 'Compassion based Intervention (ABCT) + Usual specialized treatment in mental health. ABCT consists of 8 weekly groupal sessions of 120 minutes/session (10-16 people). Written material and sound recordings will be offered as support elements. The estimated duration of the program is two months.', 'interventionNames': ['Behavioral: Compassion based Intervention']}
- {'label': 'TAU', 'type': 'ACTIVE_COMPARATOR', 'description': 'Usual specialized treatment in mental health (psychological or/and psychiatric)', 'interventionNames': ['Other: TAU']}

Interventions:
- {'type': 'BEHAVIORAL', 'name': 'Mindfulness based Intervention', 'description': 'MBSR consists of 8 weekly groupal sessions of 150 minutes/session (10-16 people). Written material and sound recordings will be offered as support elements. The estimated duration of the program is two months', 'armGroupLabels': ['MBSR+TAU']}
- {'type': 'BEHAVIORAL', 'name': 'Compassion based Intervention', 'description': 'ABCT consists of 8 weekly groupal sessions of 120 minutes/session (10-16 people). Written material and sound recordings will be offered as support elements. The estimated duration of the program is two months.', 'armGroupLabels': ['ABCT+TAU']}
- {'type': 'OTHER', 'name': 'TAU', 'description': 'Usual specialized treatment in mental health (psychological or/and psychiatric)', 'armGroupLabels': ['TAU']}

Primary Outcomes:
- {'measure': 'Depression Anxiety Stress Scales', 'description': 'In the MBSR based intervention group. This scale is a set of three self-report scales designed to measure the emotional states of depression, anxiety and stress. Each of the three DASS-21 scales contains 7 items, divided into subscales with similar content. The range for each subescale is 0-21 (But this scores will need to be multiplied by 2 to calculate the final score). This questionnaire also gives us a one-dimensional global measure of emotional distress that will be considered as the main study outcome. It is composed by all the 21 items configuring a general factor, and it will be taken as a continuous dimensional variable that ranges from 0 to 126.', 'timeFrame': 'Baseline'}
- {'measure': 'Depression Anxiety Stress Scales', 'description': 'In the ABCT based intervention group. This scale is a set of three self-report scales designed to measure the emotional states of depression, anxiety and stress. Each of the three DASS-21 scales contains 7 items, divided into subscales with similar content. The range for each subescale is 0-21 (But this scores will need to be multiplied by 2 to calculate the final score). This questionnaire also gives us a one-dimensional global measure of emotional distress that will be considered as the main study outcome. It is composed by all the 21 items configuring a general factor, and it will be taken as a continuous dimensional variable that ranges from 0 to 126.', 'timeFrame': 'Baseline'}
- {'measure': 'Depression Anxiety Stress Scales', 'description': 'In the TAU control group. This scale is a set of three self-report scales designed to measure the emotional states of depression, anxiety and stress. Each of the three DASS-21 scales contains 7 items, divided into subscales with similar content. The range for each subescale is 0-21 (But this scores will need to be multiplied by 2 to calculate the final score). This questionnaire also gives us a one-dimensional global measure of emotional distress that will be considered as the main study outcome. It is composed by all the 21 items configuring a general factor, and it will be taken as a continuous dimensional variable that ranges from 0 to 126.', 'timeFrame': 'Baseline'}
- {'measure': 'Depression Anxiety Stress Scales', 'description': 'In the MBSR based intervention group. This scale is a set of three self-report scales designed to measure the emotional states of depression, anxiety and stress. Each of the three DASS-21 scales contains 7 items, divided into subscales with similar content. The range for each subescale is 0-21 (But this scores will need to be multiplied by 2 to calculate the final score). This questionnaire also gives us a one-dimensional global measure of emotional distress that will be considered as the main study outcome. It is composed by all the 21 items configuring a general factor, and it will be taken as a continuous dimensional variable that ranges from 0 to 126.', 'timeFrame': 'Post-treatment 8 weeks from baseline in 8 weeks MBSR intervention group'}
- {'measure': 'Depression Anxiety Stress Scales', 'description': 'In the ABCT based intervention group. This scale is a set of three self-report scales designed to measure the emotional states of depression, anxiety and stress. Each of the three DASS-21 scales contains 7 items, divided into subscales with similar content. The range for each subescale is 0-21 (But this scores will need to be multiplied by 2 to calculate the final score). This questionnaire also gives us a one-dimensional global measure of emotional distress that will be considered as the main study outcome. It is composed by all the 21 items configuring a general factor, and it will be taken as a continuous dimensional variable that ranges from 0 to 126.', 'timeFrame': 'Post-treatment 8 weeks from baseline in 8 weeks ABCT intervention group'}
- {'measure': 'Depression Anxiety Stress Scales', 'description': 'In the TAU control group. This scale is a set of three self-report scales designed to measure the emotional states of depression, anxiety and stress. Each of the three DASS-21 scales contains 7 items, divided into subscales with similar content. The range for each subescale is 0-21 (But this scores will need to be multiplied by 2 to calculate the final score). This questionnaire also gives us a one-dimensional global measure of emotional distress that will be considered as the main study outcome. It is composed by all the 21 items configuring a general factor, and it will be taken as a continuous dimensional variable that ranges from 0 to 126.', 'timeFrame': 'Post-treatment 8 weeks from baseline in TAU control group'}
- {'measure': 'Depression Anxiety Stress Scales', 'description': 'In the MBSR based intervention group. This scale is a set of three self-report scales designed to measure the emotional states of depression, anxiety and stress. Each of the three DASS-21 scales contains 7 items, divided into subscales with similar content. The range for each subescale is 0-21 (But this scores will need to be multiplied by 2 to calculate the final score). This questionnaire also gives us a one-dimensional global measure of emotional distress that will be considered as the main study outcome. It is composed by all the 21 items configuring a general factor, and it will be taken as a continuous dimensional variable that ranges from 0 to 126.', 'timeFrame': 'Six-months follow-up'}
- {'measure': 'Depression Anxiety Stress Scales', 'description': 'In the ABCT based intervention group. This scale is a set of three self-report scales designed to measure the emotional states of depression, anxiety and stress. Each of the three DASS-21 scales contains 7 items, divided into subscales with similar content. The range for each subescale is 0-21 (But this scores will need to be multiplied by 2 to calculate the final score). This questionnaire also gives us a one-dimensional global measure of emotional distress that will be considered as the main study outcome. It is composed by all the 21 items configuring a general factor, and it will be taken as a continuous dimensional variable that ranges from 0 to 126.', 'timeFrame': 'Six-months follow-up'}
- {'measure': 'Depression Anxiety Stress Scales', 'description': 'In the TAU control group. This scale is a set of three self-report scales designed to measure the emotional states of depression, anxiety and stress. Each of the three DASS-21 scales contains 7 items, divided into subscales with similar content. The range for each subescale is 0-21 (But this scores will need to be multiplied by 2 to calculate the final score). This questionnaire also gives us a one-dimensional global measure of emotional distress that will be considered as the main study outcome. It is composed by all the 21 items configuring a general factor, and it will be taken as a continuous dimensional variable that ranges from 0 to 126.', 'timeFrame': 'Six-months follow-up'}

Please estimate the sample size based on the assumption: 
Alpha of 0.05, beta risk <0.2 (power of 80%), and a patient attrition rate at follow-up of approximately 15%-20%.
Sample size
        Sample size has been estimated considering the main hypothesis (âABCT+TAUâ will be more effective than âMBSR +TAUâ for treating depressive, anxiety or adjustment disorders). There are no references on previous direct comparisons between ABCT and MBSR groups, so we will perform an exploration in this respect. According to the literature and considering the TAU active control comparator used, we assume a large effect of ABCT and a small effect of MBSR in the primary outcome of general affective distress.28 36 51 73 Therefore, with an equal 1:1:1 allocation rate, supposing a large difference between ABCT and MBSR conditions, with an ES of roughly d=0.80, accepting an alpha of 0.05 and a beta risk <0.2 in a bilateral contrast, we will need approximately 75 patients: 25 in the MBSR condition, 25 in the ABCT group and 25 in the TAU condition. Assuming a patient attrition rate at follow-up of approximately 15%â20%, the total sample size needed will be established at 90 patients (30 in each group).