The management of ALS patient’s respiratory functions is a challenge for physicians, and it is very important to reach a deeper understanding of this topic.
A caregiver’s distress level has been previously studied [24
], but, as far as we know, none of these have investigated the relation between a caregiver’s psychological characteristics and clinical aspects of ALS patients. Our study is the first attempt to evaluate the interaction between psychological features of caregivers and their patient’s clinical data.
According to the obtained results, respiratory function is related to a patient’s perception of social support and to the psychological distress of their caregivers. In particular, the patient’s FVC and PCF present negative correlations with their caregiver’s depression, proneness to anxiety, and burden and a positive relation with perceived social support. Low levels of depression, trait anxiety, and burden experienced by caregivers correspond to higher values of FVC and PCF.
A first possible explanation for these results is that the clinical status of an ALS patient has a great influence their caregiver’s psychological well-being. It is quite intuitive, according to clinical experience, that the worsening of the physical condition of ALS an patient produces worries and burden to their relatives and close friends, in accordance with previous literature [9
]. Considering the correlational design of the study, however, another possible explanation cannot be excluded, even if counterintuitive: Change can be promoted by an improvement in the quality of assistance, paying more attention to oral care, cough assistance, and secretion management. Relatively unworried caregivers may be able to provide a better assistance to their relatives by paying more attention to their needs, thus promoting better health condition for ALS patients. Conversely, high levels of depression, trait anxiety, and burden of caregivers could have had a negative effect on the quality of care in our sample. Previous findings by Chio and colleagues indicate that married ALS patients, after NIV, lived statistically longer than non-married [27
]. These works, together with the present results, lead to the intriguing hypothesis that there could be something in the patient-caregiver relationship that influences the patient’s physical condition. Our data do not provide real empirical support to the hypothesis, but this issue should be addressed by future studies.
This small study has some limitations. No causal inferences between variables can be made in cross-sectional studies. Moreover, the relatively small sample size increases the risk of a type-II error in the interpretation of data. However, correlations are quite high, augmenting the validity of our results. Furthermore, the average FVC and PFC values were relatively high for ALS patients, although the results can not be generalized to all ALS subjects. The use of the Trait form of the STAI provides information about a subject’s proneness to anxiety and not the experienced level of anxiety. Therefore, more information about state anxiety will be required in future studies. Another limitation is that the sample includes only patients and caregivers with absent psychopathology prior to the ALS diagnosis. Dedicated works could address the clinical peculiarities of people with ALS and a previous psychopathology.
Even if the hypothesis of a partial causal relation between the caregiver’s psychological well-being and the patient’s respiratory function could be wrong, the importance of the caregiver’s role and social support should not be underestimated by physicians who work with ALS patients, considering the impact on the patient’s quality of life [28
]. Together with patients, medical staff could take care of their closest relatives, providing psychological and social support. However, these kind of integrated treatment would seem not to be practical in most ALS clinics, which are already stretched to provide all the services the patients need.
In order to increase the scientific knowledge aimed at the improvement of clinical practice, further works are required to investigate the complex relationship between caregiver psychological characteristics and clinical course of ALS. Moreover, studies about possible psychological interventions are warranted in the ALS field [30
]. We suggest the realization of a randomized clinical trail that compares patient-caregiver couples who receive psychological support with couples that do not, with both clinical and psychological outcomes.