Emotional stress in primary caregivers of people with a diagnosis of amyotrophic lateral sclerosis

Abstract

Theoretical framework

Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease that causes loss of motor function and is associated with cognitive and behavioral disturbances. ALS patients are dependent on primary caregivers, who face high levels of emotional stress, including anxiety, depression and burden.

Objective

To assess emotional stress in primary caregivers of ALS patients by measuring levels of anxiety, depression and burden.

Method

Descriptive, quantitative, cross-sectional study. A sample of 40 primary caregivers was included. The Zung Self-Rating Anxiety Scale (SAS-15), the Zung Self-Rating Depression Scale (SDS) and the Zarit Burden Interview (ZBI) were used.

Results

The caregivers presented mild to moderate levels of anxiety, with an average value of 1,61 on the SAS-15, indicating the presence of emotional stress. Depression levels were normal, and no significant burden was observed. No statistically significant differences were found between men and women, nor did age influence the results. Significant positive correlations were observed between levels of anxiety and depression (r = .64; P < .05), anxiety and burden (r = .67; P < .05) and between depression and burden (r = .67; P < .05).

Conclusions

Emotional stress is prevalent among primary caregivers of ALS patients, with anxiety being the most affected aspect. The results highlight the need to address the psychological well-being of caregivers.

Resumen

Marco teórico

La Esclerosis Lateral Amiotrófica (ELA) es una enfermedad neurodegenerativa progresiva que causa pérdida de la función motora y está asociada con alteraciones cognitivas y conductuales. Los pacientes con ELA dependen de los cuidadores/as primarios, quienes enfrentan altos niveles de estrés emocional, incluyendo ansiedad, depresión y sobrecarga.

Objetivo

Evaluar el estrés emocional en los cuidadores/as primarios de pacientes con ELA mediante la medición de los niveles de ansiedad, depresión y sobrecarga.

Método

Estudio descriptivo, cuantitativo y transversal. Se incluyó una muestra de 40 cuidadores/as primarios. Se utilizaron la Escala de Autoevaluación de Ansiedad de Zung (SAS-15), la Escala de Autoevaluación de Depresión de Zung (SDS) y el Cuestionario de Sobrecarga del Cuidador de Zarit (ZBI).

Resultados

Los cuidadores/as presentaron niveles de ansiedad entre leves y moderados, con un valor promedio de 1,61, en la SAS-15, constatando la presencia de estrés emocional. Los niveles de depresión fueron normales y no se observó sobrecarga significativa. No se hallaron diferencias estadísticamente significativas entre hombres y mujeres, ni la edad influyó en los resultados. Se observaron correlaciones positivas significativas entre los niveles de ansiedad y depresión (r = .64; P < .05), ansiedad y sobrecarga (r = .67; P < .05) y entre depresión y sobrecarga (r = .67; P < .05).

Conclusiones

El estrés emocional es prevalente entre los cuidadores/as primarios de pacientes con ELA, siendo la ansiedad el aspecto más afectado. Los resultados destacan la necesidad de abordar el bienestar psicológico de los cuidadores/as.

Introduction

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that causes loss of motor function, as well as cognitive and behavioural alterations, due to the degeneration of upper and lower motor neurons.^1,2

The disease has a heterogeneous clinical presentation, with symptoms such as muscle weakness, spasticity, dysarthria, dysphagia, and respiratory failure.² Consequently, people with ALS lose functional independence, including the ability to walk, communicate, or perform self-care tasks.¹ Symptoms typically emerge between the ages of 50 and 65.³

As ALS is incurable, care focuses on improving and maintaining the patient's quality of life.⁴ Authors such as Magelssen et al.⁵ have addressed the ethical challenges posed by this disease at the end of life, concluding that clinical management at this stage should prioritise the patient's quality of life by incorporating appropriate palliative care when necessary.

People with ALS require the support of primary caregivers due to the deterioration caused by the disease. These caregivers are key figures who must receive support from health professionals in order to face the challenges posed by the disease.⁶

A caregiver looks after a sick or dependent person, helping with daily activities such as feeding, personal hygiene, taking medication, or accompanying them to health services.⁷

Given the significant support required by people with ALS, the care routine is often exhausting and can be prolonged, causing emotional distress for the caregiver.⁸

Emotional distress is defined as 'a multifactorial, unpleasant experience of a psychological, and/or social spiritual nature that may interfere with the ability to cope effectively with illness… ranging from feelings of vulnerability, sadness, and fears to problems that can become disabling, such as depression, anxiety, or social isolation'.⁹

Studies such as that by Limonero et al.¹⁰ have analysed emotional distress by interviewing caregivers of patients with advanced cancer and using instruments to measure anxiety, depression, stress, and overload, in addition to a clinical psychological assessment.

Several studies have observed high levels of depression in caregivers¹¹ correlating with female sex, duration of illness, and functional impairment of the dependent person. Meanwhile, the study by Hu et al.¹² observed symptoms of anxiety, mild to moderate depressive symptoms, and severe depressive symptoms in 43.9%, 26.5%, and 27.4% of caregivers, respectively. Other studies have found a relationship between greater caregiver burden and poorer health-related quality of life.¹³

Objectives

General objective

To determine the presence of emotional distress in a sample of primary caregivers of people with ALS.

Specific objectives

• •

  To analyse anxiety levels using the Zung Anxiety Self-Rating Scale-15 (SAS-15).

• •

  To analyse depression levels using the Zung Depression Self-Rating Scale (SDS).

• •

  To analyse the level of overload using the Zarit Burden Interview (ZBI).

• •

  To observe possible differences in the level of emotional distress of caregivers based on sex and age.

• •

  To analyse the relationship between the levels of caregiver anxiety, depression, and overload through a correlation test.

Method

This study forms part of a research project on people with ALS and their caregivers entitled ‘Impact of the Combined Treatment of Liposomed Polyphenols with G04CB02 on ALS Patients’ (NCT04654689, ClinicalTrials.gov), focusing on people with ALS and their caregivers.

Design and participants

A descriptive, quantitative, cross-sectional study was conducted. The final sample consisted of 40 primary caregivers of people with ALS. Recruitment was carried out via email and telephone with ALS patient associations in Spain. Caregivers were included in the study through the patients themselves using non-random convenience sampling. All caregivers signed the informed consent form, meaning no participants were excluded.

Variables and instruments

The variables analysed were the caregiver's sex (female or male), age, and relationship to the patient (wife, husband, daughter/son, sister-in-law/brother-in-law, friend, or non-family caregiver). To assess emotional distress, three validated scales were used to measure levels of anxiety, depression, and overload: SAS-15, SDS, and ZBI.

The SAS-15, developed by Zung,¹⁴ assesses symptoms of anxiety. Its 15-item Spanish version was validated by Rodríguez de Ávila et al.,¹⁵ obtaining a Cronbach's α coefficient of .81. It uses a 4-point Likert scale, ranging from 1 (never) to 4 (always). The final score is interpreted according to the following ranges: normal (0–1), mild to moderate (1.1–2), marked to severe (2.1–3), and extreme (3.1–4).

The SDS, also designed by Zung,¹⁶ assesses depressive symptoms with 20 items. Each question is evaluated using a Likert scale of 1–4 (a little of the time, some of the time, a good part of the time, and most of the time). The score is classified as: normal (25–49), mild depression (50–59), moderate depression (60–69), and severe depression (>70). The Spanish version of the scale was validated by Conde et al.,¹⁷ with a Cronbach’s α coefficient of .82.

The ZBI, developed by Zarit et al.¹⁸ and adapted into Spanish by Martín et al.,¹⁹ assesses caregiver burden in relation to aspects such as health, personal, and social life, economic situation, emotional well-being, and interpersonal relationships. Consisting of 22 items, it uses a 5-point Likert scale to measure how often the caregiver experiences feelings of overload (0 = never; 1 = almost never; 2 = sometimes; 3 = quite frequently; 4 = nearly always). Scores are interpreted as follows: no overload (≤46); mild to moderate overload (47–55); and severe overload (56–110). Analysis of the psychometric properties of the Spanish version of the ZBI by Martín-Carrasco et al.²⁰ revealed good internal reliability, with a Cronbach's α coefficient of .92.

Procedure

Before completing the questionnaires, people with ALS and their caregivers received information about the study. The questionnaires were administered by specialist mental health nurses and psychologists from the research group.

Data were collected in person between January and June 2023. The questionnaires were completed in paper format under the supervision of a researcher to ensure an appropriate environment, resolve any queries participants had during the process, and reduce the risk of bias.

The research team collected, analysed, and interpreted the data exclusively, respecting personal data protection laws at all times. Participants were informed that participation in the study was voluntary, anonymous, and unpaid. The personal data of the study participants were coded to ensure confidentiality.

The project was approved by the Clinical Research Ethics Committee of La Fe Hospital in Valencia (EudraCT 2021-001989-38) and was conducted in accordance with the Declaration of Helsinki.²¹

Statistical analysis

Statistical analysis was performed using SPSS v.25 (IBM Corporation).

The normality of the sample was analysed using the Shapiro–Wilk test to determine whether the quantitative variables followed a normal distribution.

Univariate descriptive statistical analysis was performed to study the distribution of the sample according to sex (percentages), age (mean, standard deviation, minimum and maximum values), and the relationship between the caregiver and the patient. The results obtained from the three instruments (mean, standard deviation, minimum and maximum values) were also analysed).

For the bivariate analysis, simple linear regression analysis was used to analyse the correlations between the participants' age and the results in the three instruments. Additionally, bivariate correlations between the results of these scales were studied by calculating Pearson's correlation coefficient.

The Mann–Whitney U test was performed to compare the questionnaire results according to gender, and to check for statistically significant differences in emotional stress between women and men.

As three measurement instruments were used, the internal consistency of the different scales was analysed using Cronbach's α coefficient.

A value of P < .05 was considered significant. The data are presented as arithmetic means or percentages with a standard deviation (SD). Confidence intervals (CI) were calculated at 95%.

Results

This study analysed a final sample of 40 caregivers with a mean age of 52.78 years (SD = 11.49) (Table 1), of whom 65% were women (n = 26) and 35% were men (n = 14).

Table 1.

Sociodemographic characteristics of the sample.

	Total	Female caregivers	Male caregivers
n	40	26	14
Average age (years)	52.78	52.42	53.43
SD	11.49	11.56	11.75

n: number of participants; SD: standard deviation.

Source: compiled by the authors.

Of the sample (n = 40), most of the caregivers were relatives or friends of the patient (n = 39), primarily their wife (n = 18) or husband (n = 13), but also children (n = 5), sister-in-law/brother-in-law (n = 2), or friend (n = 1). The rest (n = 1) was a formal caregiver.

The results obtained on the three scales were as follows (Table 2): an average score of 1.61 (SD = .51) was obtained on the SAS-15, interpreted as a mild-moderate level of anxiety. For the SDS, an average result of 40.53 (SD = 8.63) was obtained, interpreted as a normal level of depression. Finally, the ZBI showed an average score of 29.53 (SD = 16.29), interpreted as an absence of overload.

Table 2.

Results on the assessment scales.

	n	Minimum	Maximum	Mean	SD
SAS-15	40	1	3.40	1.61	.51
SDS	40	21	57	40.53	8.63
ZBI	40	4	64	29.53	16.29

n: number of participants; SD: standard deviation.

Source: compiled by the authors.

The Shapiro-Wilk normality test was performed to determine whether the study sample followed a normal distribution for the quantitative variables. The non-parametric Mann-Whitney U test (Table 3) was used to compare levels of anxiety, depression, and overload between men and women (P < .05). The results showed that there were no significant differences between the groups for any of the three instruments. Confidence intervals (CI) were calculated at 95%. The U and P values, with their corresponding CIs, were as follows: anxiety (U = 150.50; P = .37; 95% CI: −.452 to .168); depression (U = 172.50; P = .78; 95% CI: −.353 to .267), and overload (U = 179.00; P = .93; 95% CI: −.323 to .287).

Table 3.

Non-parametric test for the sex variable and statistical test results^a.

	Anxiety	Depression	Overload
Mann-Whitney U test	150.50	172.50	179.00
P	.37	.78	.93
95% CI	–.452 to .168	–.353 to .267	–.323 to .287

Source: compiled by the authors.

a

Grouping variable: sex; P < .05; 95% CI: 95% confidence interval.

Although no significant differences between the sexes were found, the average anxiety scores on the SAS-15 were 1.50 (SD = .44) for men and 1.67 (SD = .55) for women. For overload levels, as measured by the ZBI, the average values were 28.71 (SD = 7.30) for men and 29.96 (SD = 9.40) for women. The average depression scores were almost identical: 40.50 (SD = 16.54) for men and 40.54 (SD = 16.47) for women.

The results of the simple linear regression analysis (Table 4) were not significant, with values of F (3) = .616; P = .609, indicating that the age variable was not useful for predicting the results of the instruments. Neither were the regression coefficients for anxiety, depression, and overload significant, with P-values greater than .05 and confidence intervals (CIs) including zero: anxiety (B = 4.176; 95% CI: −6.402 to 14.753; P = .801); depression (B = .198; 95% CI: −0.435 to .830; P = .530); overload (B = −.100; 95% CI: −.447 to .247; P = .562).

Table 4.

Linear regression between the age variable and the scale scores.

Regression	Sum of squares	df	Mean square	F	P
Age-Anxiety	.36	1	.36	1.38	.24
Age-Depression	87.11	1	87.11	1.17	.28
Age-Overload	73.15	1	73.1	.27	.60

df: degrees of freedom; F: ANOVA test statistic; P < .05.

Source: compiled by the authors.

Table 5 shows the correlations between the three scales as determined by Pearson's correlation coefficient. Significant positive correlations were found between anxiety, depression, and overload levels. The highest correlations were between overload and depression (r = .67; P < .05) and between overload and anxiety (r = .67; P < .05). These findings indicate that the greater the overload, the greater the depression and anxiety, and vice versa. A positive correlation was also observed between anxiety and depression (r = .64; P < .05).

Table 5.

Correlations between the results of the three scales.

		SAS-15	SDS	ZBI
SAS-15	Pearson correlation	1	.64^a	.67^a
	Sig. (2-tailed)		.00	.00
	N	40	40	40
SDS	Pearson correlation	.64^a	1	.67^a
	Sig. (2-tailed)	.00		.00
	n	40	40	40
ZBI	Pearson correlation	.67^a	.67^a	1
	Sig. (2-tailed)	.00	.00
	n	40	40	40

n: number of participants; Sig. (2-tailed): P-value indicating the statistical significance of the Pearson correlation.

Source: compiled by the authors.

a

The correlation is significant at the .05 level (2-tailed).

As three measurement instruments were used for the study, the internal consistency of the different scales was analysed using Cronbach's α coefficient (Table 6). The results showed a Cronbach's α of .92 for the SAS-15, a Cronbach's α of .83 for the SDS, and a Cronbach's α of .91 for the ZBI. These results indicate high internal consistency in the three scales used in the sample, i.e., the items that comprise them are closely related to each other and reliably measure the same construct in the sample studied.

Table 6.

internal consistency of the assessment instruments.

	Cronbach’s α	Cronbach’s α based on standardised items	n. of items
SAS-15	.92	.92	15
SDS	.83	.83	20
ZBI	.91	.92	22

Source: compiled by the authors.

Discussion

The main objective of this study was to evaluate the emotional distress experienced by primary caregivers of people with ALS. Specifically, anxiety, depression, and overload levels were measured. Additionally, potential differences in emotional distress levels were analysed according to caregiver sex and age. Correlations between anxiety, depression and overload levels were also studied.

On average, anxiety levels were mild to moderate, confirming the presence of emotional distress in the sample. Meanwhile, the level of depression was, on average, within the normal range. Previous studies, such as that by Schischlevskij et al.,²² found that the greater the degree of patient dependence, the higher the levels of anxiety and depression in a sample of 248 caregivers of people with ALS.

No caregiver overload was observed in this study. However, Conroy et al.²³ found high levels of overload in a sample of 172 caregivers. Schischlevskij et al.²² also found high levels of caregiver overload in their sample of 248 caregivers. It is important to note that these studies considered values of ≥24 on the ZBI to reflect a high burden, which is common for validations of this scale in other settings,²⁴ whereas in Spanish-speaking environments, values of ≥47 are considered to indicate overload.^19,20,25

No significant sex-based differences were observed in the sample studied for any of the three instruments, although it was found that the average values for anxiety, depression, and overload levels were higher in women than in men. Previous studies, such as that by Rabkin et al.,²⁶ concluded that age and sex were not related to caregiver depression in a sample of n = 71. However, studies such as that by Maksymowicz-Śliwińska et al.,¹¹ with a sample of 164 caregivers, found differences between the sexes in depression levels, with women being more likely to suffer from it.

Caregiver age was not associated with higher levels of overload, anxiety, or depression in the sample studied. However, the study by Tsai et al.²⁷ found, in a sample of 328 caregivers of patients with dementia, that older caregivers experienced greater overload.

Positive correlations were found between levels of anxiety, depression, and overload, coinciding with studies such as that by Pagnini et al.,²⁸ in which the same positive correlation was observed, and these variables had a negative relationship with social support.

There are several reasons why the results obtained in this study differ from those of previous studies. One of the main reasons is the sample size. Previous studies collected a larger sample size, which may have influenced the accuracy and representativeness of the results. Another important reason is that the ZBI results are interpreted differently depending on their validation environment.

This study examined the relationship between caring for a highly dependent person and emotional disturbances such as anxiety. It also found that anxiety, depression, and overload levels were positively correlated. These findings highlight the importance of a biopsychosocial approach to care, which considers the primary caregiver, who is at risk of developing emotional disturbances.

Nurses can reduce the emotional distress of caregiving by training caregivers, for example by explaining how to feed patients, attend to their hygiene needs, move them, attend to their respiratory needs, and administer medication. This would reduce the caregiver's uncertainty and improve the care provided to the person with ALS, thereby improving the quality of life for both the caregiver and the person receiving care.

Some aspects that could be explored in future research include forming a larger sample and studying new variables: socio-occupational status, chronic diseases of the caregiver, financial benefits, type of housing and degree of adaptation, deterioration of the person with ALS, and time since diagnosis. Additionally, specific ALS scales could be employed, such as the ADI-12.

The main limitation of this research study is the small number of participants (n = 40), and it is therefore important to note that the differences observed in the results compared to other studies may be due to the smaller sample size in the present study. Another limitation is that the interpretation of the ZBI scale results varies according to the cultural context. In this study, values ≥47 were considered to indicate overload, in accordance with the validations of the scale in the Spanish-speaking environment. However, other studies have considered values ≥24 to indicate a high burden, which could affect direct comparisons of the results with research in different contexts.

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.