This paper looks at changes in trust in the Parliament and the political parties using data from an online panel survey from Spain, which includes 4 waves carried out between 2010 and 2012. I describe intra-individual variation and give an explanation to changes in trust in those institutions in a context of deep economic crisis, with huge ratios of unemployment. The main hypothesis of work relies on the idea that economic personal grievances –situation of unemployment, loss of income– might affect how individuals trust in their political institutions. However, the findings only confirm this situation partially, for which I suggest and alternative explanation: personal economic grievances push individuals to think collectively instead of punishing the institutions for their personal economic situation. The paper is organized as follows: first, I work for addressing the puzzle of political trust, a concept that has been widely used in the literature but still has some problems with regards to the denomination and its measurement. Second, I assess the political relevance of the concept, its trends and consequences. Third, I focus on explaining political trust change at the individual level in a context of economic crisis such is the Spanish case; I address the particularities of this case of study, in both terms of low levels of trust and also a deep economic crisis. Then, I write down the main hypotheses of work, before running the analysis and presenting the results. Finally, I conclude with a discussion section.