عوامل بالینی رضایت از زندگی در اسکیزوفرنی مزمن: اطلاعات از مطالعه CATIE

Objective Quality of life is seen as an important outcome variable for patients with schizophrenia. However, the precise definition of this construct varies and has often been used to define health-related domains. The present study sought to focus on global life satisfaction as a key subjective domain and determine its relationship with clinical variables. Method The study sample included 1437 patients with chronic schizophrenia who participated in the Clinical Antipsychotic Trial of Intervention Effectiveness (CATIE) study. Patients were evaluated with a comprehensive battery of assessments capturing symptoms, cognition and medication side effects, among other variables. Life satisfaction was evaluated with a global self-report item. Results Greater depressive symptoms were the most robust indicator of worse life satisfaction. Lower life satisfaction was also associated with poorer psychosocial functioning, greater symptoms of anxiety, apathy and more negative attitudes toward medication. Taken together, these variables explained 20% of the variance in life satisfaction scores. Positive symptoms and other medication side effects also negatively influenced life satisfaction scores. Conclusions These results affirm that clinical variables have an adverse effect on the overall subjective well-being of patients with schizophrenia. The relatively small amount of variance explained, though, argues for a better understanding of those other variables that contribute to life satisfaction.

In 1948 the World Health Organization defined health as not only the absence of disease, but also the presence of physical, mental and social well-being (World Health Organization, 1948). Since, most branches of medicine began systematically assessing patients' subjective views of illness and symptoms (Guyatt et al., 1989), and from this the construct of quality of life (QoL) emerged as a promising clinical domain (Testa and Simonson, 1996 and Gladis et al., 1999). While there is still debate as to the definition of this construct and what it encompasses (Vaillant, 2003 and Awad and Voruganti, 2012), indicators of QoL routinely include satisfaction with life/happiness (SWL), subjective evaluations of specific living conditions and objective assessments of functioning (Katschnig, 1997 and Gladis et al., 1999). As a result, QoL is often conflated with subjective evaluation of ‘health status’ (Guyatt et al., 1989), while the construct of SWL has received comparatively little attention in its own right. Indeed, this important global domain is often lost in the focus on QoL. The concept of SWL differs from subjective quality of life or satisfaction with aspects of treatment as assessed by scales such as the Drug Attitudes Inventory (Hogan et al., 1983). These latter concepts assess subjective reactions to objective conditions (e.g. satisfaction with housing and subjective experience of treatment). In contrast, SWL involves a global subjective assessment of all aspects of an individual's life and is, by definition, agnostic to objective conditions, although such conditions may potentially influence overall SWL (Shin and Johnson, 1978, Lehman, 1983, Diener, 1984 and Gill and Feinstein, 1994). The construction of a global SWL estimate is inherently personal, influenced by individual values and goals, and not simply a composite of subjective evaluations regarding objective life conditions. Life satisfaction or level of happiness has been argued by some to be the highest human achievement as it is a core component of a person's life (Shin and Johnson, 1978 and Diener, 1984), although some have argued for the existence of different flavors of happiness (Wilson, 1967 and Seligman, 2002). Conversely, impoverished SWL represents a diminished sense of being and can pose a risk for serious adverse long-term outcomes such as suicide (Koivumaa-Honkanen et al., 2001). There have been several examinations of the clinical correlates of SWL among individuals with schizophrenia, reflecting the shift toward a more comprehensive model of outcome evaluation that includes improved functioning and well-being (Remington et al., 2010). Many of these studies have demonstrated the adverse impact depressive and anxiety symptoms on SWL, as well as the deleterious effect of medication-related side effects (Mechanic et al., 1994, Awad et al., 1997, Heslegrave et al., 1997, Packer et al., 1997, Dickerson et al., 1998, Bengtsson-Tops and Hansson, 1999, Koivumaa-Honkanen et al., 1999, Fitzgerald et al., 2001, Huppert et al., 2001, Reine et al., 2003, Hofer et al., 2004, Melle et al., 2005, Narvaez et al., 2008, Saarni et al., 2010 and Agid et al., 2012). To this point, a recent meta-analytic study found that general psychopathology symptoms (which include depression and anxiety) were associated with worse global well-being (Eack and Newhill, 2007). These studies have unquestionably advanced our knowledge of the clinical variables affecting the overall well-being of patients with schizophrenia, as well as the differential impact of each of these clinical variables on SWL. However, these studies have some limitations that preclude generalization to a larger group of patients. The majority of these studies included a modest number of patients who experienced mild–moderate levels of symptoms. Differences in such sample characteristics across studies may account for the differential weighting that various studies give to different clinical variables. Another salient limitation is the frequent exclusion of patients who have co-morbid psychiatric diagnoses apart from schizophrenia, which again limits the generalizability of findings. Finally, many previous studies have not included comprehensive evaluations of clinical variables; several studies did not concurrently assess the influence of insight or cognition, but did nevertheless conjecture these variables to have an influence on SWL. In the present study we examined the relationship between a comprehensive set of clinical variables and SWL using a large and heterogeneous sample of patients with chronic schizophrenia. We hypothesized we would replicate previous findings demonstrating a negative link between SWL and depression, anxiety and akathisia, and also that we would uncover relationships between certain clinical variables and SWL that are of a smaller magnitude than that of depression. We are positioned to uncover such potential relationships due to increased statistical power afforded by including a large number of patients.