hopelessness influence a person's present and future QoL. The analysis of a temporal horizon was helpful in understanding the link between depression and QoL. Keywords: depression; quality of life; Schedule for the Evaluation of Individual Quality of Life; theory; time orientation Background Assessment of quality of life (QoL) has become increasingly important in health care, particularly as an evaluative method to measure outcomes of the impact of disease and interventions. To date it is unclear how research on QoL relates to other psychological constructs such as depression and anxiety. Many clinical studies assess a number of related psychosocial dimensions but without a theoretical basis for the unique contribution of each. On an intuitive level, QoL and depression can appear as opposing phenomena -- crudely representing all the positive and negative aspects of well-being. Poor QoL is sometimes seen as a consequence of depression [ 1 - 3 ]. On the other hand, poor QoL may also be a precursor to depression. In other formulations, depression can be seen as a component of QoL. Whatever the implicit models of their interrelationships, there has been little theoretical attention or research to understand the relationship between depression and QoL. A theoretical approach developed by de Leval [ 4 , 5 , 8 ] tries to capture and highlight possible relationships between depression and QoL in a "three-time-dimension" theory. This theory links depression and QoL on a timeline of the past-present-future. Time can be perceived objectively and subjectively. It consists of three dimensions: past,