Severe major depression and treatment modalities

Depression treatment modalities among the elderly: do personality traits effect treatment outcomes?

Depression is a severe disorder that can have devastating effects on the elderly. This disorder can affect all aspects of life, including physical, emotional, and psychological well-being. Although research has determined that combination therapy (antidepressants and psychotherapy) is the most effective treatment intervention for elderly individuals with depression, little research has focused on the influence that personality traits has on treatment outcomes. This study proposes to study the impact of personality traits on the treatment of depression among the elderly through the examination of NEO-Five-Factor-Inventory scores in comparison to improvements of Beck Depression Inventory scores between baseline and outcome measures in 3 experimental treatment conditions (antidepressants, psychotherapy, combination therapy). This study hypothesizes that combination therapy will be significantly more effective than the other treatment conditions in the reduction of depressive symptoms, and that personality traits will be significantly associated with treatment outcomes.

Introduction

Depression affects physical, role and social functioning, and can result in a high number of bed days, medical utilization, employment absence, and lost productivity (Greeenberg, Stiglin, Finkelstein & Berndt, 1993; Kessler & Frank, 1997; Kouzis & Eaton, 1994; Mintz, Mintz, Arruda & Hwang, 1992; Von Korff, Ormel, Katon & Lin, 1992; Wells et al., 1989). This debilitating disorder is also associated with more than half of all suicides (Oquendo et al., 2001), which amounts to more than 14,500 individuals per year in the United States alone. Depression has been ranked as the fourth leading cause of disease burden worldwide, and is projected to become the second leading cause of disease burden by 2020 (Murray & Lopez, 1996). Currently one in twenty people have experiences of major depression within any given year, and the lifetime risk of depression is 10% to 25% for women, and 5% to 12% for men (American Psychiatric Association, 1994). It is estimated that up to one half of these individuals seek care for depression in primary or specialized mental health care settings (Rost, Nutting, Smith, Werner, 2000), representing both a challenge and an opportunity to improve the quality of care for this disorder.

Since the American population is aging, there will inevitably be an increased number of elderly people with depression. This increase will result in an increased demand for effective treatments for depression among this population. Tools to facilitate accurate assessment and treatment monitoring are critical, given that depression often goes undetected in adolescents and adults, and most likely in the elderly as well. Even when recognized, depression may not be treated appropriately or to the extent that it should be (Jones, Badger, Ficken, Leeper, & Anderson, 1987; Schulberg, Katon, Simon, & Rush, 1998; Wells, Katon, Rogers, & Camp, 1994).

What are some effective treatment strategies for depression that could be extended to the elderly population? The depression guidelines put forth by the agency for Health Care Policy and Research suggest that medication and psychotherapy be implemented as first-line treatments for patients with moderate to severe depression. Furthermore, clinicians may also find it necessary to plan more extensive interventions when depression is the primary contributor to an individual's functional impairment. Depression measures can be used to monitor individual and aggregate patient outcomes across time. By evaluating an individual's response to treatment, the clinician can adjust his or her therapeutic strategy depending on whether the patient is improving or not. By aggregating patient outcomes over time, clinicians can compare their results to those of other clinicians and systems of care, and furthermore initiate quality improvement efforts accordingly.

Research has determined that forms of psychosocial intervention, such as cognitive behavioral therapy (CBT), behavioral therapy, cognitive bibliotherapy, reminiscence group therapy, and problem-solving group therapy, may be effective treatment interventions for geriatric depression. A combination of psychotherapy and antidepressant medication might be an appropriate treatment for individuals presenting with moderate to severe depression. A study by Thompson, Coon, Gallagher-Thompson, Sommer & Koin (2001) examined the efficacy of a specific antidepressant medication (Desipramine), a specific psychotherapy (CBT), and a combination approach, (CBT and Desipramine), in the treatment of depression among the elderly. The results indicated that, although patients in all three treatment conditions experienced substantial improvement in their depressive symptoms, the patients receiving the combination treatment and those receiving CBT alone showed greater improvements than those patients that only received Desipramine. Therefore, the researchers concluded that CBT is an effective treatment for depression in older adults, and that the combination of pharmacotherapy and CBT may be of particular usefulness among patients who do not effectively respond to either antidepressants or psychotherapy alone.

Personality traits and disorders can have an effect on depression and the effectiveness of treatments for depression. Hirschfeld and Shea (1992) discovered that dependency is the trait most associated with depression. Although there have been some conflicting findings, numerous empirical studies have demonstrated that dependent individuals are more likely to become depressed following loss and interpersonal rejection, conflict, and disapproval; those less prone to dependency are more likely to become depressed following events that cause perceived threat to their independence, achievement, mastery and power (Coyne, 1998).

There have been relatively few studies of the relationship between personality and depression among an elderly population. However, studies that have been conducted indicate a high prevalence of comorbid personality disorder and depression among elderly patients in an acute hospital setting (Kunik, Mulsant, Rifai, Sweet, Pasternak & Zubenko, 1994). Also, personality disorders among this older population were associated with a younger age of onset of depression and poorer treatment outcomes. Schneider, Zemansky, Bender and Sloane (1992) also reported greater personality dysfunction among recovered depressed elderly patients compared with nondepressed elderly. However, in an investigation how personality factors contribute to the prognosis of late-life depression, Burvill, Hall, Stampfer & Emerson (1991) determined that personality factors, such as neuroticism or extraversion, were not predictive of treatment outcomes in an elderly population.

Personality traits may affect the manner in which elderly patients respond to treatment for depression. Among a non-elderly population, Autonomous personality traits have been found to be related to favorable antidepressant responsiveness, while dependent traits are associated with higher depression levels following the medication phase (Peselow, Robins, Sanfilipo, Block & Fieve, 1992). Investigation into how personality traits factor into the effectiveness of treatment for depression among the elderly population is warranted and is addressed in this proposed study.

The current proposed investigation will have two research objectives, to a) replicate the results of previous studies that indicated effective treatment modalites among the elderly, and b) examine the relationship between personality factors and treatment outcomes for depression in the elderly. The hypotheses of the proposed study are that a) the results of the current study will indicate that a combination of antidepressants and psychotherapy will be a more effective treatment for depression among the elderly than either treatment modality alone, and b) there will be a significant relationship between personality traits and response to treatment for depression, similar to those findings observed among the nonelderly population. The purpose of this study is further understanding of the mechanisms involved in effectively treating depression among the elderly.

Method

Participants

Subjects for this proposed study would be 100 depressed elderly individuals, 50 males and 50 females, between the ages of 65 and 85 who have checked into community health outpatient programs in a large metropolitan center. Demographic variables, such as socioeconomic status and race/ethnicity, will be randomized in appointment to experimental conditions

Materials

The Beck Depression Inventory (BDI) will be employed to measure depressive symptomatology at baseline as well as treatment outcome in both experiments. The NEO-Five-Factor Inventory will be utilized in the second experiment to assess dominant personality traits among the participants so that the relationship between personality traits and changes in depressive symptomatology can be examined. A demographics questionnaire will also be administered to the participants prior to participants being assigned to experimental conditions.

Procedure

Experiment 1 - Participants will be randomly assigned to one of three experimental conditions: antidepressant group, cognitive behavior therapy (CBT) group, or combination therapy group (CBT and antidepressants). Participants will complete ten weeks in their prescribed therapy groups. Depressive symptoms will be assessed before commencement of therapy (baseline) and after the completion of the period of therapy (outcome) using the Beck Depression Inventory.

Experiment 2 - Participants will all complete the NEO-Five-Factor-Inventory prior to commencement of treatment in experiment 1. These scores will be used to identify dominant traits among participants and will be used to assess whether these traits in any way affect treatment outcomes.

Results

Experiment 1 - It is hypothesized that there will be a significant difference in BDI scores in all experimental conditions between baseline and outcome measures. It is also expected that improvements in BDI scores in the combination therapy condition between baseline and outcome will be significantly greater than those observed in the antidepressant and psychotherapy-only conditions.