A longitudinal study on quality of life and depression in ALS patient–caregiver couples

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder of the CNS with an unknown etiology. It is characterized by a progressive loss of cortical and spinal motor neurons, causing bulbar and spinal palsy. Usually death occurs 2 to 4 years after onset, mostly due to respiratory failure. Despite the extreme severity of ALS, patients with ALS tend to be characterized by a sort of stoical indifference toward their condition¹; in cross-sectional studies the rate of depression in patients with ALS has been estimated between 11% and 48%, according to the rating scales utilized and the patients’ clinical status.^2–6 Also, ALS caregivers’ attitude and reactions appear somehow different from those who care for patients with other severe and chronic neurologic conditions, such as Alzheimer disease, Parkinson disease, and multiple sclerosis.^7–9 However, it is not clear whether ALS patients’ and caregivers’ attitudes modify with disease progression.

In order to gain a better understanding about the time trends of patients’ quality of life (QoL) and depression with the worsening of their clinical status, we performed a longitudinal study on a series of patients with ALS attending our facility. We also assessed their caregivers, in order to find out whether their QoL, depression, and burden worsened due to the physical decline of the persons they were caring for.

Methods.

We recruited 55 consecutive patients with probable, probable laboratory-supported, or definite ALS, according to revised El Escorial criteria,¹⁰ visited in our ALS clinic or at patients’ homes by one of the authors during a 2-month period (March to April 2004). Patients with clinically overt frontotemporal dementia (FTD), clinically evaluated, were excluded from the study. However, FTD was not formally tested. After having signed an informed consent, the patient and his or her caregiver were interviewed by the same psychologist, with the same modalities, and, when possible, in the same setting; all couples were interviewed separately. The second interview was scheduled 9 months (±1 month) after the baseline interview. The second interview was administered by the same psychologist, with analogous procedure and setting, whenever possible. The caregiver was the person indicated by the patient as his or her main informal caregiver, in most instances a family member. The caregiver was the same in both interviews. Professional (paid) caretakers, such as nurses, were not considered in this study. The research was approved by our Institutional Review Board.

Patients underwent the following tests: Zung Depression Scale (ZDS, range 20 to 80, with scores up to 50 indicating not depressed; 50 to 59 signifying minimal to mild depression; 60 to 69 indicating moderate depression; and 70+ indicating severe depression)¹¹; Self-Perceived Burden Scale (SPBS, range 25 to 125, with higher scores indicating that the patients perceived themselves to cause a higher burden to their caregivers)¹²; and McGill Quality of Life Questionnaire (MQoL, range 1 to 10, with 5 subscales also ranging from 1 to 10, where higher scores indicate greater levels of well being).¹³ All scales have been used in ALS and have been validated in other disorders.^4,9 The patients’ physical status was measured with the Amyotrophic Lateral Sclerosis–Functional Rating Scale (ALS-FRS, range 0 to 40, with higher scores indicating a better physical status). We also subdivided the ALS-FRS in four subscales: bulbar symptoms (range 0 to 12); upper limbs (range 0 to 12); lower limbs (range 0 to 12); and respiration (range 0 to 4).

Caregivers were administered ZDS, MQoL, and Caregiver Burden Inventory (CBI, range 0 to 100, with 5 subscales each with a range of 0 to 20, where higher scores stand for a heavier burden).¹⁴

Comparisons were performed with Student t-test and Fisher exact test. All tests were two-tailed. A p level of < 0.05 was considered significant. Since multiple correlations were performed, Bonferroni correction was applied. All statistical calculations were made using the Statistical Package for Social Sciences (SPSS), version 12.0 for Windows (SPSS, Chicago, IL).

Results.

We performed two consecutive interviews with 31 (56.4%) of the 55 patient–caregiver couples who originally entered the study. The reasons for dropouts were death (20 patients), unfeasibility to administer the battery of tests because of patients’ worsening physical status (2 patients), and withdrawal of consent (2 patients). The patients who were not interviewed two times were significantly older and had a worse ALS-FRS score at the time of the first interview, but did not show any significant difference in the ratings of the administered scales at baseline.

The second interview was administered a mean of 278 days after the first interview (SD 27.7, median 283). Only the patients and caregivers who underwent both examinations were included in the calculations. All demographic data are referred to the time of the first interview.

Discussion.

In a previous cross-sectional study, we have found that patients’ level of disability, especially at spinal level, and caregivers’ depression were the factors with the strongest correlation with caregivers’ burden; patients’ feeling to be a burden, measured with SPBS, correlated with their own depression, but not with their level of physical impairment.⁹ In the present longitudinal study, we found that caregivers’ overall psychological well-being worsened over time, whereas the patients’ remained relatively stable: the correlation between patients’ ZDS and SPBS weakened at the second testing, while the correlation between caregivers’ ZDS and CBI got more significant; more importantly, quality of life was higher in caregivers than in patients at baseline, but became higher in patients at the second testing. The steadiness of patients’ QoL during the course of ALS, despite the worsening of clinical status, has also been found in other studies.^15,16 In one study, after 1 year of follow-up, patients maintained a positive self-perception of their health despite physical deterioration, and QoL was significantly related to self-perception of health and religiosity.¹⁵ A more recent article found that the patients did not assess their QoL before the start of symptoms differently at the reassessments later in the course of the disorder, indicating that there was no tendency to glorify life before the symptoms started as the disease progressed.¹⁶ The substantial steadiness of QoL and the non-significant increase of depression in patients over time may be due to several factors: patients’ acceptance of and adjustment to the disease over time and with the approach of death,^6,16,17 use of denial¹⁸ as well as optimism, flexibility, and humor as psychological defenses,¹⁹ or a reduction of insight, related to patients’ subtle cognitive impairment.^20,21

Caregivers reported a reduction of QoL, although not significant. The most impaired caregivers’ MQoL domain was Psychological Health, but the only domain showing a significant decrease over time was Physical Symptoms. For patients, as one would expect, the most impaired QoL domain was Physical Symptoms, even though its score did not worsen over time, while the actual physical symptoms, measured by the ALS-FRS, did; this might be due either to patients’ reframing, or to a neglect toward their actual status. On the contrary, the significant increase of the QoL Support domain for patients with ALS may indicate that they positively perceive the help, both physical and psychological, they receive from their caregivers.

The significant increase of caregivers’ burden and the reduction of their QoL between the two examinations is likely to be related to the accumulation of stress and fatigue over time,²² as also indicated by the significant increase of the Emotional Burden subscore of the CBI. However, interestingly, the most impaired CBI domain, both at baseline and at second interview, was Time-dependence Burden, confirming that the limitation of time for oneself is the main source of caregivers’ dissatisfaction.^9,23

Patients seem to be aware that their caregivers get more and more burdened over time,^9,22 but this understanding does not appear to be complete, since the SPBS scores did not modify between the two interviews, despite the significant increase of caregivers’ burden. This discrepancy could indicate that the patients’ concept of burden is somehow different from what is experienced by their caregivers.^24,25

Caregivers’ depression increased over time proportionally more than patients’, even though the absolute scores of the former remained lower than those of the latter. An increase of depression over time among caregivers was found in a recent prospective study, which assessed the caregivers two times over 1 year.²⁶ In the same article, overall caregivers’ psychological distress (a composite measure combining mood, burden, and strain) was found to increase significantly aver time. In our study 9.7% of caregivers at baseline and 19.3% after 9 months had scores over the cut-point of 50, indicating a mild to moderate depression. Similarly, in another article, 9.5% of caregivers were classified as depressed at baseline, 14.3% after a mean of 6 months and 19.0% after a mean of 12 months.²⁶

While QoL of patients with ALS has been largely investigated, relatively few studies have assessed caregivers’ QoL, and their coping and adaptation issues. Some studies^9,23 have pointed out the lack of leisure time and the impossibility to go out of the home, participate in social activities, see friends, and take care of their own needs as the main sources of caregivers’ concerns. Even though most caregivers did not feel that their patients’ requests were excessive or unreasonable, some of them never reach a successful adaptation.²³ Also the changes in relationships that occur between patients and significant others during the course of the disease may be devastating for caregivers.²⁷ A study²⁸ has classified caregivers’ unfavorable life conditions into seven categories: defenselessness, negative affection, hopelessness, sadness, depression, isolation, and loneliness. Another study has pointed out that 86.4% of patients and 79.7% of caregivers endorsed existential issues as their main stressors, followed by physical concerns (patients, 80.3%, and caregivers, 76.3%), and by psychological factors (38% both in patients and caregivers).²⁴ Finally, a recent study has found that psychological distress in ALS caregivers was related to negative social support and their baseline satisfaction with their social relationships.²⁶

ALS is considered a family disease, meaning that it involves every member of the patient's entourage. Moreover, some evidence shows that caregivers’ mental status has great influence on patients, in terms of physical, psychological, and existential well being^3,9; therefore, any planning regarding ALS care should not overlook caregivers’ physical and psychological conditions, together with their coping abilities and needs.

Accordingly, interventions specifically designed to enhance the communication effectiveness between patients and caregivers might improve the psychological well-being of both parties, helping patients to be more aware of their caregivers’ needs, and caregivers to get more apt to accept their straining but invaluable role.²⁹ Such interventions should require a psychological follow-up, including serial neuropsychological assessments of patients’ mental status where possible,³⁰ in order to establish whether patients actually lack empathy necessary to feel and understand their caregivers’ distress, and to help caregivers coping with such a challenging task, by providing them a deeper knowledge about the psychological status of the persons they care for.