Spanish Journal of Psychology (2015), 18, e46, 1–8. © Universidad Complutense de Madrid and Colegio Oficial de Psicólogos de Madrid doi:10.1017/sjp.2015.48 In recent decades there has been increased interest in programs and psychological interventions based on mindfulness (Eberth & Sedlmeier, 2012). A search of the PsycInfo database using the keyword “mindfulness” gives us a total of 485 items – if the search is restricted to the period 1965 (the year the first indexed article appears in PsycInfo with this keyword) to 2004. However, the same search between January 2005 and December 2010 provides us with 1,842 items. One reason for this dramatic increase in scientific produc- tion related to mindfulness is the effect psychological techniques based on mindfulness have had on a variety of psychological variables, such as brain activity, in both clinical and non-clinical contexts. Thus, for example, in the clinical context, a meta-analysis by Grossman, Niemann, Schmidt and Walach (2004) found mean weighted effect sizes of .50 for mental health problems (depression, anxiety, sleep disorders etc.) and .42 for physical health problems (medical symptoms, physical pain or physical disability). In the non-clinical popula- tion, Sedlmeier et al. (2012) found a mean weighted effect size of .28. In another similar study, also conducted on a non-clinical population, Eberth and Sedlmeier (2012) found mean weighted effect sizes ranging from .21 to .40. The categories of the dependent variables eval- uated in these studies include aspects as diverse as anxiety, attention, memory, regulating emotion, verbal fluency, emotional stability, self-fulfillment and per- sonal well-being. With respect to changes in brain activity, studies incorporating neuroimaging techniques by means of functional Magnetic Resonance Imaging (MRI) show that the practice of mindfulness produces greater activa- tion of brain regions involved in sustained attention, response inhibition and attention to distracting sounds and less brain activation in regions related to emo- tions and discursive thought (Brefczynski-Lewis, Lutz, Schaefer, Levinson, & Davidson, 2007), as well as changes in grey matter concentration in brain regions related to learning, regulating emotions and self- referential processing (Hölzel et al., 2011). The corre- lation between these changes and the cumulative amount of hours of meditation suggests a possible plasticity of such mechanisms (Brefczynski-Lewis et al., 2007). It has also been observed that mental training in cultivating positive emotions through compassion meditation alters the activation of circuits related to empathy and theory of mind in response to stimula- tion. That is, it improves empathic responses to social stimuli (Lutz, Brefczynski-Lewis, Johnstone, & Davidson, 2008). In addition to this, meditation increases the activity of the Anterior Cingulate Cortex (ACC) Assessing Mindfulness on a Sample of Catalan-Speaking Spanish Adolescents: Validation of the Catalan Version of the Child and Adolescent Mindfulness Measure Ferran Viñas, Sara Malo, Mònica González, Dolors Navarro and Ferran Casas Universitat de Girona (Spain) Abstract. Background: Interest in mindfulness has increased over the last decade, resulting in several mindfulness- based interventions being developed and their efficacy empirically demonstrated. The practice of mindfulness has been associated with low levels of anxiety or depression and improved quality of life or personal well-being. The aim of this study is to translate the Child and Adolescent Mindfulness Measure (CAMM) and adapt it to Catalan so as to analyze its internal consistency and construct and convergent validity. Method: The CAMM was administered to a sample of secondary school students ranging in age from 11 to 16 years old. Results: The Catalan version of the CAMM shows a good fit with the unidimensional model and internal consistency similar to the original version (α = .80). Furthermore, CAMM scores correlated positively with subjective well-being, temperamental dimensions of effortful control and self-esteem. Conclusions: The Catalan Version of CAMM is a valid and reliable measure of mindfulness skills. Received 24 April 2014; Revised 12 December 2014; Accepted 13 January 2015 Keywords: mindfulness, assessment, well-being, self-esteem, psychometric properties. Correspondence concerning this article should be addressed to Ferran Viñas. Quality of Life Research Institute. Universidad de Girona, C/ Mª Aurèlia Capmany, 63-65. Mòdul M-20, 1ª planta. Despacho 132. Campus Montilivi. 17071 Girona (Spain). Phone: +34–972418980, Fax: +34–972418032. E-mail: ferran.vinas@udg.edu