Several findings were evident from our analyses of changes in quality of life over the course of diverse psychotherapies for patients with a variety of psychiatric disorders. First, our results showed that positive quality of life improves moderately over the course of psychotherapy. Second, impairments in quality of life and the degree of change in quality of life vary considerably by disorder. Patients with major depressive disorder or borderline personality disorder had the most impairment in positive quality of life. Those with major depressive disorder or generalized anxiety disorder changed the most in positive quality of life. Patients with panic disorder changed the least in quality of life from baseline to termination; however, panic disorder patients had a relatively high mean quality of life score at baseline. The third finding was that there were moderate sized correlations between changes in quality of life and changes in symptoms and interpersonal functioning from intake to termination. Thus, as symptoms and interpersonal problems improve, so does quality of life. There was little evidence, however, that change in symptoms or interpersonal problems caused subsequent improvement in quality of life, or vice versa. One exception was a significant correlation between improvement in quality of life from intake to termination and change in anxiety symptoms from termination to follow-up.
Our findings are consistent with those of previous studies demonstrating improvements in positive aspects of quality of life over the course of psychotherapy (Elkin et al., 2006
; Frisch et al., 2005
; Seligman et al., 2006
). The study by Elkin et al. that investigated changes in positive quality of life for CT and interpersonal therapy (IPT; Klerman et al., 1984
) for major depressive disorder was the most similar to the current study. In the Elkin et al. study, pre-post effect sizes for change in positive quality of life of 1.64 for CT and 1.66 for IPT were reported. These effect sizes are somewhat larger than those found here for the MDD patients. However, unlike the quality of life measure used in the present study, the measure of quality of life (General Life Functioning scale) developed and used by Elkin et al. was found to correlate very highly with the BDI (r
= −0.86 at termination). Other differences between the studies in terms of the treatments and patients samples may also explain the relatively-more modest effect on positive quality of life found here.
The current study extends previous efforts in several notable ways. The first is presentation of changes in individual domains of quality of life. Perhaps not surprisingly, individual psychotherapy had its greatest influence on aspects of positive quality of life that primarily related to individual feelings and goals, including satisfaction with one’s self-esteem, love, play, and life goals. The larger social context of life, such as satisfaction with one’s neighborhood and community, showed less change over the course of psychotherapy. It may be that for many people, there is little interest in attempting to improve one’s satisfaction with the neighborhood and community. In fact, the neighborhood and community items had among the lowest importance ratings on the QOLI at baseline.
A second way the current study extends previous findings is through examination of both directions of potential causal influence in the relation of quality of life to symptoms and interpersonal functioning. Elkin et al. (2006)
found that level of quality of life at termination was significantly associated with the number of depression-free weeks and levels of social and work functioning at the 6-month follow-up. Although depressive symptoms at termination were controlled in Elkin et al.’s analyses, change from baseline to termination in depressive symptoms was not. When we conducted a similar analysis as was performed in the Elkin et al. (2006)
study, a similar finding emerged: more positive quality of life at termination was associated with improvement (or less deterioration) in depressive symptoms from termination to follow-up. However, when we controlled for baseline levels of quality of life, the prediction of change in depressive symptoms from termination to follow-up was no longer significant. Nevertheless, these results suggest that a relatively positive quality of life at termination, regardless of how much quality of life has improved, helps reduce the chances of depressive relapse, or leads to further improvements, following treatment. Furthermore, we did find evidence that improvement in quality of life was associated with subsequent improvement in symptoms in regard to anxiety symptoms.
The current study, however, provided no evidence that improvement in symptoms leads to subsequent improvement in quality of life. This latter causal direction might be expected if symptoms are causing a restriction of activities and interactions with other people. Alleviation of symptoms might be expected to help people become more engaged in various activities and interests, thereby increasing their positive quality of life. An important caveat here is that our failure to obtain evidence for this direction of causal influence does not prove there is no such influence. The timing of the assessments may not have been ideal for capturing this direction of causal influence. A shorter time frame, perhaps a matter of weeks, might be needed to detect the impact of symptom reduction on improved quality of life. The possibility, however, that change in positive quality of life is not primarily a function of prior change in symptoms needs to be considered. The potential lack of such a causal influence raises the question of what is responsible for positive changes in quality of life. It may be that different aspects of the treatment process, or events occurring independent of treatment, drive improvement in positive quality of life independent of any effects on symptoms. Moreover, additional treatment obtained by patients during the follow-up period may have attenuated any relation between quality of life and symptoms during this period. Further research would be useful to test hypotheses about the potential causal influences on change in positive quality of life.
A final way that the current study extends previous findings is through the inclusion of several different psychiatric disorders. Although quality of life improved for all disorders, there were some interesting differences among the disorders. To a certain extent, such differences were a function of differences in baseline levels of impairment in quality of life (i.e., depressed patients were highly impaired at baseline and therefore had the most room for improvement). A potential exception was generalized anxiety disorder. Patients with this disorder were significantly less impaired at baseline compared to those with major depressive disorder but showed pre-post mean changes in quality of life that were almost equal to that seen for patients with major depressive disorder. Additional research is needed to confirm this exploratory finding and to understand the underpinnings of it, should it be reliable. Although patients improved in quality of life, the mean post-treatment scores of the QOLI for patients with major depressive disorder, borderline personality disorder, and generalized anxiety disorder were all substantially below the population norms for the QOLI. Frisch (1994)
reported that adults’ normative scores on the QOLI are in the range of 2.0 to 3.75 (25th
percentile). The obesity group (post-treatment M
= 2.98), however, and somewhat the panic disorder group (post-treatment M
= 1.84), end treatment within or close to the population norm.
We can speculate on several clinical implications of these results. The relative lack of impact of psychotherapy on one’s satisfaction with neighborhood and community may be a limitation of individual psychotherapy. It may also simply take longer in psychotherapy to change these aspects of quality of life. Practical issues (i.e., moving to a new neighborhood) might also be important here. In general, though, the relatively low importance ratings for these domains suggest that, for most patients, overall quality of life is not largely dependent on these factors. For those patients who do value satisfaction with neighborhood and community, however, this finding may highlight the need for developing new interventions that would enhance satisfaction with these areas of life.
Generalizing further, a model of therapy that specifically develops and targets interventions to improve each individual’s most important domains of quality of life may have the greatest potential for improving overall quality of life. An example of such a treatment has been provided by Frisch (2005)
. Whether treatments like the one proposed by Frisch, or the positive psychotherapy approach of Seligman et al. (2006)
, are able to improve positive quality of life more so than standard psychotherapies that focus on alleviating negative feelings, problematic thoughts, and symptoms, needs to be addressed in future studies. Conceivably, the best approach might involve an integration of techniques that alleviate symptoms and correct negative thoughts and behaviors with interventions designed to target positive elements of life. Because it is clear that some disorders (major depressive disorder, borderline personality disorder, generalized anxiety disorder) end treatment with standard psychotherapies at a mean level substantially below population norms, a greater focus on positive quality of life in these treatments may be necessary to move such patients closer to a “normal” level of positive quality of life.
It should be noted, however, that standard psychotherapies often include interventions that address more positive aspects of patients’ functioning and coping and therefore the characterization that standard psychotherapies only emphasize the negative (symptoms and deficits) may be somewhat misleading. In Luborsky’s (1984)
SE therapy, for example, several of the supportive techniques focus on positive aspects of patients’ lives. These include goal setting (i.e., goals are often phrased as positive behaviors, such as “socializing more often”), conveying a hopeful attitude, recognition of progress on goals and accomplishments, and encouraging a positive bond in therapy. Similarly, in CT, interventions include goal setting, planning and engaging in enjoyable activities, developing a sense of mastery, and increasing social support (Beck et al., 1979
). Cognitive interventions also focus on the development of a more positive explanatory style (Seligman et al., 1988
), which has been associated with performance in occupational domains (Satterfield, Monahan, & Seligman, 1997
; Seligman, Nolen-Hoeksema, Thornton, & Thornton, 1990
). These positive features of standard SE therapy and CT may account, in part, for the positive changes in quality of life seen in the current data.
A variety of limitations of this research are important to mention. We aggregated data from several studies involving a variety of disorders and treatments. Confounding between the disorders and treatments and the relatively low sample sizes within each study limited statistical power for detecting differences due to disorders or treatments. Despite the limited statistical power, some differences did emerge that can serve to guide future hypothesis testing research in this area. Another limitation was that the analysis of individual domains of quality of life relied on individual items from the QOLI measure, and individual items typically have relatively lower reliability. As mentioned, to unravel the causal influence that symptoms and quality of life have on each other, measurement of these constructs at different time periods is likely necessary (rather than the broad time frames we examined: intake, termination, 6–12 month follow-up). An additional limitation is that the correlation between pre and post treatment QOLI scores was moderately high, making it difficult for change on this measure to correlate highly with other measures. Finally, although the therapies were conducted by experienced therapists who were trained and supervised in the therapy methods, no data on adherence/competence was available across all studies. However, some of the studies (e.g., Crits-Christoph et al., 2005
; Crits-Christoph et al., 2006
; Brown et al., 2004
) did assess adherence/competence, which in general was adequate.
Despite these limitations, the current study suggests that positive quality of life should be given greater attention in both clinical work and research on psychotherapy, and points the way for additional research on this important construct.