Depression and anxiety disorders are prevalent in people with chronic kidney disease (CKD), especially in advanced stages and on dialysis. ¹ It is estimated that depression affects 25% and anxiety 23% of dialysis patients and according to other studies, the prevalence can range from 27 to 30% ² and from 69% to 71% respectively. ³

Depression is characterized by feelings of sadness, guilt, disinterest, low self-esteem, insomnia, hyporexia/anorexia, fatigue, and lack of concentration and pleasure. ⁴ It has personal repercussions at the psychological, emotional, and behavioral levels, ^{2, 5} and affects treatment compliance, so detecting the factors associated with depression should be a priority. ^{3, 5} Risk factors for depression include being female, low socioeconomic status, stressful life events, lack of social support, serious or chronic illness, and a history of eating disorders. ⁵

Anxiety is characterized by feelings of uncertainty and fear and can manifest as palpitations, tremors, indigestion, nervousness, shortness of breath, and diaphoresis, often being confused with other pathologies. ⁶ However, anxiety disorders have been less studied in patients with advanced stages of CKD, and their impact is largely unknown in this population. ^{1, 2}

Chronic kidney disease (CKD) is strongly associated with an increase in mental health problems, including depression and anxiety. ^{1, 2, 3} There is also evidence of its association with central nervous system diseases, cognitive dysfunction, and dementia. People with CKD are more likely to have strokes and subclinical cerebrovascular disease than the general population. It has also been reported that uremic toxins related to kidney damage may predispose individuals to neurological disorders. ⁷

A systematic review covering information on 80,932 individuals with CKD from 27 countries found an overall prevalence of depression of 26.5% and 39.6% when using the International Classification of Diseases. Depression was significantly more common among individuals on chronic hemodialysis compared to pre-dialysis patients (29.9% and 18.5%, respectively). ⁸ Another study of 376 patients with CKD, a third of whom were on hemodialysis, found that 74% suffered from depression, with mild depression predominating (16%). Among the factors significantly associated with depression, they found the duration of CKD since diagnosis, the level of independence in performing routine activities at home, the ability to generate income, and lifestyle changes. ⁹

The association between depression and sociodemographic variables has been documented in patients with CKD at different stages. ^{10– 12} Gender, educational level, ¹⁰ monthly income, ¹³ family support, ^{10, 11} employment status, duration of CKD, age group, ¹⁰ status, and social support ¹² are associated with clinical depression, as are the variables negative perception of the disease, low self-esteem, and severe pain interference. ¹⁰ Socioeconomic variables affect the quality of life of people with CKD and are significantly associated with overall subjective well-being, physical well-being, and environmental circumstances. ¹⁴

Other studies with CKD patients report that single marital status and female gender ^{13, 15} were significantly associated with depression and anxiety, as well as unemployment and polypharmacy. ¹⁵ Bivariate and multivariate logistic regression in another study showed that social support and time since CKD diagnosis were significantly associated with depression and anxiety. Other associated factors include uric acid levels ¹⁶ and family history of mental illness, with patients with CKD and comorbidities being 1.7 times more likely to develop such mental disorders ^13.

Depression and anxiety among patients with CKD have been assessed using a range of inventories and scales, notably the Hospital Anxiety and Depression Scale (HADS). HADS has been validated in multiple studies as an effective tool for identifying symptoms of anxiety and depression in diverse populations, including the public, individuals with chronic or psychiatric conditions, and patients undergoing both hemodialysis and peritoneal dialysis. ²⁰

In Peru, most patients with CKD who require dialysis are treated by Essalud and the Integral Health Insurance system. From 2019 to 2023, 205,501 cases of CKD were diagnosed (2.16% of the total insured population), of which 10% were in stage G5 as confirmed by laboratory tests. ²¹ Current treatment modalities do not offer a cure, but they can alleviate symptoms and prolong the life of patients who come to dialysis with great fear because they associate this condition with mortality, radical changes in their lifestyle and personal routine, and uncertainty about the progression of this chronic disease. ²² No research on mental illnesses such as depression, anxiety, stress, and sleep disorders in CKD patients on dialysis was found in the Peruvian medical literature. Therefore, the objective of this study is to analyze the prevalence of depression and anxiety in CKD patients and the demographic, clinical, and laboratory factors associated with these pathologies. The findings will provide primary data on this issue in a systematic manner in order to adapt the protocols for the diagnosis and treatment of depression and anxiety in patients with CKD.

The Table 1 shows that females predominate in both groups (60% in peritoneal dialysis versus 52.2% in hemodialysis). Patients on peritoneal dialysis were married (60%), employed (50%), and had a higher level of education (57.5%). Patients on hemodialysis were single (47.8%), unemployed (44.8%), and had a primary or secondary level of education (37.3% for each level).

The main primary causes of CKD in both groups were hypertension and type 2 diabetes mellitus. In terms of comorbidities, more than half of the patients on hemodialysis had no associated diseases (56.7%), while in peritoneal dialysis, heart disease and hypertension were the most prevalent (47.5%).

Sleep disorders were more common in patients undergoing peritoneal dialysis (70%) than in those undergoing hemodialysis (46.3%), as was a higher drug burden (4 to 6 drugs), whereas in hemodialysis the use of 1 to 3 drugs was more common. Moderate to severe anxiety symptoms were more common in the peritoneal dialysis group (37.5%) than in the hemodialysis group (29.9%), while hemodialysis patients showed a higher proportion of moderate to severe depressive symptoms (41.8%).

In Table 2, 27.1% of men and 37.3% of women presented moderate to severe symptoms of anxiety. The majority of single people (41.9%) showed moderate to severe symptoms of anxiety, while 51.1% of married people did not show such symptoms. According to educational level, 66.7% of illiterate individuals showed mild symptoms, and patients with primary, secondary, and higher education predominantly showed no symptoms of anxiety. No significant association was found between anxiety and sociodemographic characteristics (sig > 0.05).

In the case of depression, 50% of men showed moderate to severe symptoms, while in the group of women, 39.7% did not show symptoms of depression. Most patients over 60 years of age had moderate to severe symptoms, which predominated in all marital status subvariables. According to educational level, 66.7% of illiterate patients showed mild symptoms, while moderate and severe symptoms predominated in patients with primary and secondary education. In terms of employment status, 48.6% of active workers showed mild symptoms, while moderate and severe symptoms predominated in retirees and the unemployed, with a statistically significant association (sig < 0.05).

In Table 3, thirty-nine percent of patients with sleep disorders presented moderate to severe symptoms of anxiety, and among those without sleep disorders, 47.9% showed no symptoms of anxiety. Regarding the number of medications, 55.6% of those who consume more than six medications show severe symptoms of anxiety. However, no statistically significant association was found (p > 0.05).

Regarding depression and its relationship with the variables described above, it was found that 45.8% of those with sleep disorders showed moderate to severe symptoms of depression and 28.8% showed mild symptoms. Regarding the amount of medication, 46.5% of those who took 1 to 3 medications or more than 6 medications showed moderate to severe symptoms of depression; with no evidence of a significant association (p > 0.05).

In Table 4, about the variables age and duration of dialysis, there were no differences among the study groups. However, significant differences were observed in several biochemical parameters, such as albumin (t: 2.767; p:0.003) and hemoglobin values, which are higher in hemodialysis patients (t: 2.326; p = .012), with a moderate effect size (d = 0.504). With regard to urea, the highest levels are found in peritoneal dialysis patients (t:-1.956; p: .027), as are calcium values (t: −1.669; p: .049) and parathyroid hormone levels (t: −2.391; p: .011), with mainly moderate effect sizes, suggesting that the type of dialysis influences the biochemical profile of patients.

Table 5: In relation to anxiety, only hemoglobin showed a statistically significant inverse correlation (rho = −0.197; p = 0.042), indicating that lower hemoglobin levels were associated with higher anxiety levels. No significant relationship was observed among anxiety and dialysis duration, albumin, urea, calcium, phosphorus, or parathyroid hormone (p > 0.05).

With regard to depression, a significant relationship was identified with urea (rho = −0.204; p = 0.036), hemoglobin (rho = −0.199; p = 0.041), and phosphorus (rho = −0.228; p = 0.019), indicating that when hemoglobin and phosphorus levels decrease, depression levels increase. The duration of dialysis, albumin, calcium, and parathyroid hormone did not show a statistically significant association with depression (p > 0.05).

Table 6: The multivariate ordinal regression model indicates that anxiety in dialysis patients is mainly associated with older age, lower calcium levels, and single marital status. In contrast, the remaining biochemical parameters, comorbidities, gender, educational level, and drug treatment do not show a significant association with anxiety.

Table 7: The ordinal logistic regression model shows that hemoglobin is inversely associated with the level of depression (B = −0.404; p = .046), acting as a protective factor. Likewise, the presence of sleep disorders significantly increased the probability of higher levels of depression (B = 1.058; p = .026). The model shows adequate fit and explains 43.3% of the variability (Nagelkerke’s R ² = .433).

A total of 107 patients with stage G5 chronic kidney disease (CKD) undergoing dialysis during the study period were studied; 67 were on hemodialysis (48% men and 52% women) and 40 were on peritoneal dialysis (40% men and 60% women). The average age of the patients was 55.134 ± 15.43 and 58.325 ± 15.75 years, respectively.

CKD is a health problem that negatively affects patients’ quality of life and is associated with various psychiatric conditions. ¹² It is believed that these patients live with chronic stress that increases with the severity of kidney damage. ³ On the other hand, dietary restrictions, associated comorbidities, adverse effects of medication, changes in self-perception, and fear of dying are more pronounced in the final stages of CKD. ¹³ Therefore, hemodialysis patients are at greater risk for mental illness, mood changes, and functional disabilities, among other changes. ^{12– 15}

Mental health problems such as anxiety, ^{1– 3, 6, 11, 15, 17} depression ^{1– 2, 9– 11, 17} and sleep disorders ^{3, 5, 14} in patients with G5 CKD have been widely described in a series of studies that include demographic data such as age, marital status, employment status, educational level, and clinical data on patients. One study reports that among hemodialysis patients, there was a predominance of patients aged 59.1 ± 16, male, married, illiterate, and unemployed, ¹ and another study found that 72.31% of patients with CKD were married or had a partner. ³² In this study, females predominated in both dialysis groups, with a higher proportion in peritoneal dialysis patients. Hemodialysis patients were mostly single, unemployed, and had primary and secondary education, while peritoneal dialysis patients were predominantly married, employed, and had higher education.

Regarding the primary causes of end-stage renal disease (ESRD), studies report diabetes, ^{1, 33} glomerulonephritis, ³³ hypertension, ^{1, 33} and vascular nephropathy. ³³ In 25.6% of cases, the primary cause is unknown. ¹ Diabetes mellitus and hypertension share common pathophysiological mechanisms for the development and progression of ESRD ^{34, 35} and it has been described that the microvascular complications characteristic of DM are largely responsible for the progression to stage 5 ESRD requiring dialysis or kidney transplant ^{36, 37} ; It is also noted that high blood pressure is both a cause and a consequence of CKD. ³⁸ In the present study, the main primary causes of end-stage CKD, in order of frequency, are hypertension and type 2 diabetes mellitus, regardless of the type of dialysis. The primary cause of CKD was unknown in 15% of patients on hemodialysis and 12.5% of patients on peritoneal dialysis; these values are lower than those reported in other studies, which indicate that the primary cause of CKD is unknown in up to 25.6% of cases. ¹

Diabetes mellitus and hypertension are reported among the most frequent comorbidities of CKD ^{33, 39} as well as a history of cardiovascular disease. ³³ In the present study, heart disease/hypertension and sleep disorders predominated in the peritoneal dialysis group, while in the hemodialysis group, more than 56% showed no comorbidities and, to a lesser extent, heart disease and peripheral vascular disease were present. With regard to sleep disorders, one study found that insomnia is associated with comorbidities, but also with advanced age, fatigue, and pruritus. ⁴⁰ Likewise, peritoneal dialysis patients had a higher drug burden, with a predominance of 4 to 6 medications, while hemodialysis patients more frequently used 1 to 3 drugs.

It has been reported that one in five patients with CKD experience depression or anxiety when starting dialysis. ¹ In a cross-sectional study in Morocco, the prevalence of anxiety was 25.2% to 69.3% and for depression it was 34% to 67% in patients on hemodialysis. ³³ Another Moroccan study reported a prevalence of anxiety of 28.2% and depression of 23.1% in patients receiving the same treatment for CKD. ⁹ In Peru, studies have identified depression in hemodialysis patients, with a predominance of mild depression in 48.9%. ⁴¹ In the present study, the prevalence of anxiety symptoms was 56% and for depressive symptoms 69.15%, regardless of the type of dialysis. In all these studies, the HADS ^{18– 20} questionnaire was used to detect anxiety and depression symptoms and assess their severity in dialysis patients ^{19, 20} ; it is more specific than other tests because it excludes possible physical pathologies that are often somatized from its responses. ¹⁷

When using the HADS, the mean anxiety score was 7.7 ± 4.6 (range: 0–19) and the mean depression score was 7.4 ± 4.2 (range: 0–15) in hemodialysis patients. ¹ In the present study, the mean score for anxiety was 7.985 ± 4.675 and for symptoms of depression 9.833 ± 3.431 in the same type of patients; similar results for anxiety symptoms and higher frequency for depressive symptoms. Among patients on peritoneal dialysis, the mean score for anxiety was 8.725 ± 4.723 and for symptoms of depression 8.325 ± 4.208. These findings differ from a study conducted in India using the same instrument in patients on hemodialysis. The anxiety score was reported as 13.82 ± 2.73 and for depression as 12.58 ± 3.12, which the authors consider to be attributable to the prevailing conditions in the Indian population, such as low socioeconomic status, poor or inadequate access to health services, and low educational level, which are the main factors contributing to anxiety, stress, or depression in dialysis patients in that country. ³

When analyzing by type of dialysis, symptoms of depression predominated over anxiety among hemodialysis patients (with a higher proportion of moderate to severe depression symptoms at 41.8%); whereas among participants undergoing peritoneal dialysis moderate to severe symptoms of anxiety were more frequent. These results are similar to those reported in other studies, which indicate that up to 74% of hemodialysis patients suffer from depression in any of its forms ⁹ and that this pathology is significantly more frequent among individuals undergoing chronic hemodialysis compared to peritoneal dialysis (30.6% versus 20.4%; p = 0.04). ⁸ Another study reported that 41.79% of patients with advanced CKD presented anxiety symptoms, with 13.43% having a clinical diagnosis of anxiety; however, they defined advanced CKD as stage G3 and above, unlike the present study, which only includes patients with stage G5 CKD on dialysis, implying greater vulnerability and risk. Similarly, in the case of depression, they reported 25.38% of depression ³² ; unlike the present study, in which 41.8% of patients on hemodialysis present moderate and severe depressive symptoms. Another study reported that both anxiety and depression were prevalent in patients on peritoneal dialysis, a significant number of whom had previously been on hemodialysis and switched to peritoneal dialysis due to venous access exhaustion, an experience that could have negatively affected their perception of the disease. ⁴³ The fact that peritoneal dialysis is performed at home should also be considered, as being away from a healthcare facility could increase anxiety due to fear of complications during the process, whereas hemodialysis, being performed in a healthcare facility, could give patients a feeling of having medical support close at hand. Additional research is required to examine the perceptions contributing to mental health issues related to dialysis.

When analyzing the association between demographic variables such as gender, age, marital status, employment status, and educational level and symptoms of anxiety, it was found that more than 50% of women and men presented some symptoms of anxiety. Regarding the severity of symptoms, 37.3% of women and single people presented moderate to severe symptoms of anxiety, while mild symptoms predominated among illiterate people. However, no statistically significant association (sig > 0.05) was found between these variables and anxiety symptoms, unlike another study that reports a relationship between age and sleep disorders and anxiety, ¹ and between educational level and higher levels of depression and anxiety. ⁴¹

Likewise, 61% of women and 79% of men had some degree of depressive symptoms. Fifty percent of men, one-third of women, those over 60 years of age, single people, patients with primary and secondary education, retirees, and unemployed people presented moderate to severe symptoms. Among married people, 40.4% presented moderate to severe symptoms, while the majority of illiterate and active workers showed mild symptoms. In this regard, a Peruvian study reports a greater tendency toward moderate depression in older adult, widowers, followed by divorcees and singles; statistically significant findings that could be related to the absence of a partner and lack of social support to manage the disease and attend dialysis sessions. ⁴¹

This study found a statistically significant association between employment status and symptoms of depression (p < 0.05). Other studies have also found a correlation between unemployment and depression ^{43, 44} ; between advanced age, ^{1, 41} low educational level, ^{1, 10, 41, 45} retirement, poor financial situation, and depression. ⁴³ Unemployment is a risk factor for depression because it involves stressors related to economic autonomy and makes patients more vulnerable to the disease and dialysis treatment. ⁴¹

Other studies report a correlation between marital status, educational level, ^{1, 41} and socioeconomic status with depression ¹ ; data that differ from our results It has been reported that renal patients with lower educational levels have a greater tendency toward depression than those with other educational levels. ⁴¹

A systematic review of 28 studies showed that depression and anxiety are highly prevalent among patients with CKD on dialysis ⁴² ; coinciding with the high frequency of these conditions reported in the present study. As already mentioned, anxiety and depression are related to having CKD, ³ even more so if dialysis is required; therefore, it is important to consider other psychosocial factors linked to anxiety and depression, such as family support and coping styles. ⁴²

Sleep disorders are among the factors that affect the quality of life of patients with CKD, and their prevalence ranges from 41% to 83% depending on the instrument used for their assessment. They can manifest as difficulty falling asleep, difficulty staying asleep, daytime sleepiness, and chronic fatigue. ³ In the present study, 39% and 45.8% of patients with this diagnosis present moderate to severe symptoms of anxiety and depression, respectively, and the presence of sleep disorders significantly increases the likelihood of presenting higher levels of anxiety (B = 1.058; p = 0.026), according to the correlation model used, which explains 43.3% of the variability (Nagelkerke’s R ² = 0.433). Another study only reports sleep disorders as factors associated with anxiety. ¹

In another study, significantly high levels of insomnia were found in people over 60, divorced or widowed (p = 0.007), in those with comorbidity (p = 0.001), with fatigue after hemodialysis (p = 0.001), with continuous fatigue (p = 0.001), and in those who had pruritus (p = 0.007) and joint stiffness (p = 0.001). ⁴⁰ An association has also been reported among anxiety, depression, and sleep quality in older adults with albuminuria and decreased glomerular filtration rate, although the mechanism underlying this association is unclear and could be due to changes in hormone levels associated with CKD. ⁴⁶ Sleep disorders also occur due to changes in corticothalamic activity, with elevated concentrations of adrenocorticotropic hormone and cortisol, which make it difficult to fall asleep or stay asleep. Therefore, sleep quality is directly related to anxiety and depression. ^{47, 48}

Among the patients with moderate to severe anxiety symptoms, polypharmacy (>6 medications) was predominant. However, there was no statistical association between this variable and symptoms of anxiety and depression (p > 0.05), unlike another study in which anxiety and depression scores were significantly correlated with the number of medications (P = 0.022 and P = 0.003, respectively). ¹ Polypharmacy is reported to be particularly common in older adults with CKD and carries the risk of adverse effects, cumulative toxicity, drug interactions, and functional decline. ⁴⁹

It has been reported that factors related to dialysis, such as the type of treatment, travel time, waiting hours, and place of treatment, dietary restrictions, lack of family or social support, and unemployment can cause emotional disorders and, therefore, higher levels of depression and anxiety. Likewise, older age and longer time on dialysis tend to increase depression ⁴¹ ; unlike the present study, in which the demographic variables age and duration of dialysis show no differences between the groups studied and do not correlate with anxiety or depression.

In relation to the biochemical parameters studied, higher levels of albumin (t: 2.767; p: 0.003) and hemoglobin  (t: 2.326; p = .012) were observed, with a moderate effect size (d = 0.504); in hemodialysis patients, with statistically significant differences, while urea values (t: −1.956; p: .027); calcium (t: −1.669; p: .049) and parathyroid hormone (t: −2.391; p: .011) were higher in patients on peritoneal dialysis (mainly moderate effect size), suggesting that the type of dialysis influences the biochemical profile of patients. Some studies report the prevalence of hyperphosphatemia in dialysis patients, ⁵⁰ which could be related to poor phosphate binding to chelators and the complexity of dietary management; aspects that are often linked to depression. ⁴² In the present study, phosphorus levels were adequate (4.989 mg/dL for hemodialysis and 5.544 mg/dL for peritoneal dialysis); these data are similar to those of a study in which 68.2% of patients with end-stage CKD had phosphorus levels ≥5.5 mg/dL. ⁴²

In relation to biochemical parameters and anxiety, only hemoglobin showed a statistically significant inverse correlation (rho = −0.197; p = 0.042). Another study reported a significant relationship between low hematocrit levels and anxiety (p < 0.05) and low hematocrit levels (p < 0.01) and hemoglobin (p < 0.05) in patients with depression. ⁵¹ However, low hemoglobin levels caused by insufficient erythropoietin production are common in CKD, and their symptoms could be confused with those of depression. ⁵²

No significant relationship was observed between anxiety and dialysis duration, albumin, urea, calcium, phosphorus, or parathyroid hormone (p > 0.05), data similar to another study in terms of the variable dialysis duration, serum calcium, and phosphorus, which showed no association with depression and anxiety. ⁵⁰ Another study reported that patients with generalized anxiety disorder and elevated parathyroid hormone levels have poor sleep quality and higher levels of anxiety. They observed a strong relationship between peripheral biomarkers of calcium homeostasis imbalance, insomnia, poor sleep quality, and anxiety symptoms. ⁵³

In the present study, a significant relationship was identified between depression and serum urea levels (rho = −0.204; p = 0.036), hemoglobin (rho = −0.199; p = 0.041), and serum phosphorus (rho = −0.228; p = 0.019). A significant association has been reported in depression and the glomerular filtration rate (GFR), serum urea, and hemoglobin, as well as in diabetes, serum urea, and anxiety. ³³ Another study found that anxiety and depression scores have a strong negative correlation with GFR, hemoglobin, and serum calcium (p < 0.01) and a positive correlation with total white blood cell count, urea, creatinine, and phosphate (p < 0.05). ³ Likewise, in a longitudinal study of more than 2,000 patients with CKD on hemodialysis and diagnosed with depression, it was found that serum urea levels were more strongly associated with depressive symptoms than with depressive illness, although this was not statistically significant. ⁵⁴ Elevated serum urea levels in end-stage CKD are associated with accelerated atherosclerosis. Therefore, brain aging and associated pathologies such as depression and neurocognitive disorders are increased. Likewise, the carbamylation process caused by isocyanate or carbamyl phosphate leads to urea accumulation, which has an impact on oxidative stress, apoptosis, and synaptic plasticity. ^{53, 54}

The association between CKD and the high prevalence of cerebrovascular disease, cognitive impairment, and depression has also been described ^{7, 54} ; as well as the role of uremic toxins in the development of some neurological disorders, as they have direct neurotoxic actions such as astrocyte activation and neuronal death, and indirect actions via vascular effects such as endothelial dysfunction, calcification, ⁷ and inflammation. ^{7, 55, 56} Among these toxins is indoxyl sulfate, which has proven neurotoxic effects. ⁷ On the other hand, CKD is a complex pathology characterized by chronic inflammation, oxidative stress, and vascular damage, which, combined with dysregulation of the hypothalamic-pituitary-adrenal axis, is involved in the pathogenesis of depression. ⁵⁶

With regard to hemoglobin and phosphorus levels, this study found a significant inverse relationship between these variables and higher levels of depressive symptoms. As already mentioned, anemia is common in CKD patients on dialysis and can be caused by reduced erythropoietin production, erythropoietic depressants induced by uremic toxins, iron deficiency, and a decrease in the mean life span of erythrocytes. Anemia is significantly associated with depression and, together with albumin levels, is among the risk factors for depression in older patients with CKD. ⁴⁸

Another study reports a significant correlation between nutritional status assessed by serum albumin and depressive symptoms in patients with CKD, ⁵⁷ unlike the present study, which found no association between serum albumin levels and symptoms of anxiety or depression. With regard to phosphorus, it is reported that elevated levels could be related to poor adherence to phosphate binders and the complexity of dietary management, aspects that are often linked to depression. ⁴²

No statistically significant association was found in the duration of dialysis, albumin, calcium, parathyroid hormone, and depression (p > 0.05). Multivariate ordinal regression analysis to estimate factors associated with anxiety and depression demonstrated an association among anxiety and older patient age, lower calcium levels, and single marital status; hemoglobin was inversely associated with depression (B = −0.404; p = .046), acting as a protective factor. Other studies found that age showed a statistically significant inverse and weak relationship with depression and that women had higher levels of anxiety and depression than men ⁵⁸ ; that females had higher levels of depression, anxiety, and stress and experienced decreases in albumin, calcium, and vitamin D, concluding that sex influences the relationship between inflammation, nutrition, and psychological distress in hemodialysis patients. ⁵⁹

Depression also has behavioral consequences that can negatively affect medical outcomes. In patients with CKD on dialysis, depression has been associated with non-compliance with drug treatment, dietary non-compliance, weight gain between dialysis sessions, and non-attendance at dialysis sessions. ⁵⁵ Therefore, we believe that care for patients with CKD on dialysis must go beyond the biomedical model to improve clinical outcomes and treatment adherence. This requires addressing anxiety through lifestyle changes, cognitive behavioral therapy, regular exercise, and relaxation and mindfulness activities. ^{1, 42, 60}

Current research reports some factors that cause depression and mentions the bidirectional relationship between CKD and depression ⁵⁵ ; However, we believe that further study of the mechanisms of depression and the biochemical markers involved is required, as well as the implementation of protocols for evaluation at least twice a year for the timely detection of these health problems through self-administered questionnaires followed by psychological or psychiatric consultation. It is also necessary to propose improvements in the institution aimed at providing organizational, family, and personal resources to deal with anxiety and depression, including information and education about dialysis.

Among the demographic variables studied, only employment status showed a statistically significant association with depressive symptoms (p < 0.05). The primary causes of CKD were hypertension and type 2 diabetes. Sleep disorders, polypharmacy, and moderate to severe anxiety symptoms were more common among peritoneal dialysis patients, while moderate to severe depressive symptoms predominated among hemodialysis patients, without statistically significant association (p > 0.05). Significant differences were observed in albumin and hemoglobin values, which were higher in hemodialysis patients, while urea, calcium, and parathyroid hormone values were higher in peritoneal dialysis patients, suggesting that the type of dialysis influences the biochemical profile of patients.

Hemoglobin showed a statistically significant inverse correlation with anxiety symptoms, and with regard to depression symptoms, a significant relationship was identified with urea, hemoglobin, and phosphorus.

The duration of dialysis, albumin, calcium, and parathyroid hormone did not show a statistically significant association with symptoms of anxiety and depression. The multivariate ordinal regression model showed that anxiety symptoms were associated with older patient age, lower calcium levels, and single marital status, while hemoglobin was inversely associated with depression levels, acting as a protective factor. The presence of sleep disorders significantly increased the likelihood of higher levels of depression.