Mental disorders are common and represent a significant and worldwide public health concern (Smith, 2011; Vigo et al., 2016; Patel et al., 2018). The global burden of disease due to mental illness accounts for 21-32% of years lived with disability and 7-13% of disability-adjusted life-years (Vigo et al., 2016). The Lancet commission on global mental health and sustainable development just recently estimated a loss of US$16 trillion to the global economy due to mental disorders in the period 2010-2030 (Patel et al., 2018). Psychotherapy and pharmacotherapy are the two key available treatments presently offered to millions of subjects with mental disorders around the world. However, recent evidence suggests that their effects are overestimated due to several factors, such as publication bias,