One hundred and six eligible participants between 25-65 years old (Spanish higher prevalence of depression in adulthood) diagnosed with mild or moderate depression will be the sample of this project. Participants will be recruited from the Mental Health Unit (UGC Salud Mental), covering different areas of the province of Cadiz (Spain) such as Puerto Real, Chiclana de la Frontera and Vejer de la Frontera. The Mental Health Unit Director from Puerto Real Hospital is a researcher associated with this project who has specific experience with clinical experience. He will be the person in charge for the clinical depression diagnosis. Moreover, participants will perform specific depression tests at the time of recruitment to confirm their clinical status. Individuals who meet the criteria to participate in this study will sign the informed consent previously to their inclusion in this project (see inclusion / exclusion criteria section).~Sample size and statistical power~Sample size determination will be estimated with a 5% type I error (α) and 95% confidence interval establishing a level of precision (d = 0.095) for the hypothesis test to comparing two proportions. The desired sample size will be n = 96 participants and it will be increased by 10% (n = 106) to compensate the possible dropout of participants during the evaluation process of the study. Sample size for the hypothesis test to comparing two means for the intervention study will consider with a significance level alpha of 0.05 and a power of 0.95 (beta = 0.05) and considering the standard deviation for depression variable as 9.36 (Bouldering psychotherapy reduces depressive symptoms even when general physical activity is controlled for: A randomized controlled trial, Heylon, 2018; Mar; 4 (3): e00580). In this way, to detect a minimum mean difference of 8.26 between control and experimental groups for the depression variable, it is estimated that the sample size of each group should be 30 patients. Therefore, a total of 60 participants will be randomly recruited to each group balanced by sex, age and depression clinical severity. It should be taking into account that several simulations to estimate the sample size based on previous studies were performed by STATA statistical software vs. 14.0.
The goal of this randomized controlled trial is to determine the effect of an intervention program with physical activity for 12 weeks on depression, social and emotional well-being and quality of life and health in adults with mild and moderate depression. The main questions it aims to answer are:~- To determine the association of physical activity levels, sedentary behavior, sleep patterns, physical condition, diet, and general health status with mental and social well-being, and quality of life in a large sample of adult patients diagnosed with mild or moderate depression.~- To examine the predictive capacity of physical activity, sedentary behaviors, and physical condition on mild and moderate depressive disorder.~- To study the effect of a period without an intervention program with physical activity (8 weeks without exercise intervention) on the variables studied.~- To examine the role of the endocannabinoid system on depression as well as its behavior after an intervention program of physical activity.~Participants will be involved in a physical activity intervention program for 12 weeks.~Researchers will compare intervention group and control group to see if an intervention program with physical activity for 12 weeks improve depression, social and emotional well-being and quality of life and health in adults with mild and moderate depression.