Here is the design of a clinical trial:

Official Title: Ensemble Programme an Early Intervention for Informal Caregivers of Psychiatric Patients: a Randomized Controlled Trial

Included conditions:
- Psychological Distress

Study Armgroups:
- {'label': 'Ensemble + SAU (Support as usual)', 'type': 'EXPERIMENTAL', 'description': 'The five-session Ensemble program provided to informal caregivers targeted support + SAU', 'interventionNames': ['Behavioral: Ensemble programme', 'Other: SAU']}
- {'label': 'SAU (Support as usual)', 'type': 'ACTIVE_COMPARATOR', 'description': 'SAU alone which was chosen as a control condition.', 'interventionNames': ['Other: SAU']}

Interventions:
- {'type': 'BEHAVIORAL', 'name': 'Ensemble programme', 'description': "Ensemble is a individualized programme to address informal caregiver's specific unmet needs, emotions and social resources, in order to offer a targeted support in five sessions.", 'armGroupLabels': ['Ensemble + SAU (Support as usual)'], 'otherNames': ['Ensemble']}
- {'type': 'OTHER', 'name': 'SAU', 'description': 'Informal caregivers have often to manage the situation in usual different ways. Support as usual (SAU) alone consists of an informal support by patient\'s clinical team. Specific psychoeducational programs depending on patient\'s illnes (like "Profamille" for schizophrenia) or peer-support depending to the voluntary work of families\' associations. Some general professional services focused on informal caregivers or relatives in order to inform and orient them if they are avaible in the study area. No attempts have been made to standardize this treatement as SAU depend to informal caregiver\'s need and knowledge of the health system, also her/his capacity or possibility to be in contact with patient\'s clinical team.', 'armGroupLabels': ['Ensemble + SAU (Support as usual)', 'SAU (Support as usual)'], 'otherNames': ['Support as usual']}

Primary Outcomes:
- {'measure': 'Psychological state change on the Global Severity Index (GSI)', 'description': 'Assessment of psychological symptoms and psychological distress (BSI scale). The Brief Symptom Inventory (BSI) includes 53 items organized into 9 primary and clinically relevant symptom dimensions: 1) somatization, 2) obsessive-compulsive, 3) interpersonal sensitivity, 4) depression, 5) anxiety, 6) hostility, 7) phobic anxiety, 8) paranoid ideation and 9) psychoticism. This scale has also three global distress indices: The Global Severity Index (GSI), the Positive Symptom Distress Index (PSDI) and the Positive Symptom Total (PST).', 'timeFrame': 'Change from Baseline composite on the GSI score at post-test, and at 2 months follow'}

Please estimate the sample size based on the assumption: 
Î± was set at 0.05 with a power of Î²=0.80. A dropout rate of 10% will be considered.
Sample size
        The sample size was estimated using the results of the pilot study regarding the main outcome of the expected BSI Global Index. For the sample size calculation, Î± was set at 0.05 with a power of Î²=0.80. The effect size of the expected difference between the two groups was equal to Cohenâs d=0.470. Using an a priori computation for analysis of covariance (ANCOVA), the proposed trial required a total sample size of 144 participants for the two arms, 72 in each arm. In the pilot study, 1 of 22 participants dropped out, resulting in a dropout rate of approximately 5%; to increase security in the proposed study, a drop-up rate of 10% will be considered, corresponding to a dropout number of 22 participants, so the present study will recruit 160 participants. Between-group differences in pretest and post-test values will be examined using ANCOVA.