In the current study, the typical profile of a dementia caregiver was a middle-aged female relative of the person with dementia or non-dementia (88% and 60% respectively). This was consistent several previous studies [1, 9]. Ory and his associates  reported that women represented 72.5% and 68.1% of caregivers of dementia and non-dementia patients correspondingly. In the same study, while spouses were more to care for dementia patients more than non-dementia patients, children cared more for non-dementia patients rather than those with dementia. Moreover, in their review, Sharma and colleagues  found several studies revealing that females represented about 57–81% of caregivers of the elderly in different countries all over the world, especially wives and adult daughters. Higher ratio of female caregivers were reviewed by Brodaty and Donkin , ranging from 59 to 95% in different countries with nearly equal proportions of spouses and children. This is mostly because women unlike men have less tendency to institutionalize their relatives in need . Besides, it is considered as traditional role of women . Nevertheless, that is changing recently, as more men are getting involved in the care of the elderly with approximately 50% ratio  or higher . Our results show it is not the case in Egypt, which can be attributed to cultural factors, where females are providing direct instrumental and household support to elders and males providing financial support to meet elders’ daily needs and health care costs.
The relationship to the care recipient was found to be 82% children and 16% spouses in dementia patient group compared to 67% and 24% respectively in non-dementia group, with significantly increased ratio of son in the second group. That seems to be inconsistent with previous study , where there was higher ratio of spouses caring for the dementia patients while higher ratio of older children cared for the non-dementia group. This can be considered a positive point in the Egyptian society reflecting deep-rooted integrated family relations and commitment, where children take care of their parents especially on getting older and disabled.
The current study revealed that dementia caregivers were spending more hours in caring than non-dementia caregivers. A previous study  found that weekly duration of caregiving in elderly was about 4.6 h for people with average cognition compared to around 13, 22, and 46 h in patients with mild, moderate, and severe dementia in that order. Others estimated the average hours spent caring for a patient with dementia by 21.9 h per caregiver per week  or 171 h per recipient monthly .
The average duration of dementia caregiving in this study was 4.48 years. It was reported that care provider of a person with dementia spent longer time that caregivers of older adults with other conditions, 2 years or more in 54% and 50% respectively, with about 57% caregivers of people with dementias had provided care for 4 or more years . The relatively high average time in our study could be related to the criteria of selection of our sample, as we only included those who were diagnosed with dementia at least 1 year before the research.
Clinical characteristics of the study participants
Difference in activities of daily living (ADLs) and instrumental activities of daily living (IADLs) between two groups
The results of the current study also show that dementia caregivers provided significantly (P < 0.001) more aid with higher total of ADLS and IADLS (18.96 ± 3.97) than did non-dementia caregivers (8.20 ± 2.90) that comes in line with the results detected by Ory et al. , since they reported a significant increase in the total number of activities for which the dementia caregivers provided assistance (P < .001) than those assisted by non-dementia caregivers on both ADLs and IADLs. Alzheimer’s Association in their annual reports  highlighted the difference between the tasks of caregivers of elderly people with and without dementia, as 77% of care recipients with dementia demanded more assistance with at least one ADL and three IADL areas and 40% needed help with three or more ADL compared to only 20% and 14% correspondingly of the dementia-free group. Moreover, they need help with self-care and mobility (85% vs. 71%) and health or medical care (63% vs 52%).
Zarit Burden Interview
Our results showed that dementia caregivers had significantly higher scores of ZBI than non-dementia caregivers (P < 0.001).
This finding was congruent with previous studies that noted that individuals caring for people with dementia reported more personal and social burden with (55% and 52% in the order) compared to 40.9% and 38.1% of non-dementia caregivers .
Studies showed that caregivers of chronically ill patients suffer several types of burden: more than third reported schedule burden, around fifth had financial burden, 14% reported family burden, and 10% experienced health problems, which was almost stable over the time of caregiving [34, 35].
The burden in caregivers was found to be affected by the duration, amount, and intensity of the tasks  which can explain our results. It is previously mentioned that our dementia caregiver group spent longer time and had to support more ADL and IADL. Hence, it was not hardly anticipated that negative consequences were found to be spotted more in informal care provider for people with probable dementia among other factors . Even the studies that questioned the impact of caregiving and the conditions that makes it stressful considered dementia a stressful situation in which the recipient is progressively deteriorating over a long period of time without expected cure or improvement .
Study results of the relation between caregiving and psychological burden and morbidity in different cultures yielded different results . In the current study, dementia caregivers had significantly higher scores of GHQ 12 than non-dementia caregivers, with more depression and anxiety. Previous study found that dementia caregivers had high scores on GHQ which was strongly related to the assessed burden . Another study concluded that caregivers of dementia suffered from psychiatric morbidity in particular depression and anxiety more than matching general population or caregivers of other illnesses . In the same context, another study  found that care provider’s psychiatric morbidity is associated the most with the presence of dementia in the care recipients. Moreover, among wide range of physical chronic conditions assessed in recipients, only arthritis or rheumatism was to demonstrate a significant relation with caregiver’s psychiatric morbidity. Although higher levels of depression were found in spouse caregivers, there was no difference in anxiety level between both groups .
Relation between psychiatric morbidity and sociodemographic variables
No significant difference was found between both caregiver’s genders and their psychiatric morbidity. The results of studies comparing outcomes of psychiatric morbidity especially anxiety and depression for male versus female caregivers have yielded variable results. In one hand, some studies found that females had more psychiatric morbidity than males . On the other hand, another study found that male caregivers had significantly more co-morbidity than female caregivers , while some did not report gender differences in psychiatric morbidity among caregivers as in ours . Specifically, some reported females to have more depression than males [44,45,46,47].
There was no significant relationship between age, education, working status, income, and psychiatric morbidity among caregivers in our study. That agrees with other studies where psychiatric morbidity was detected in 8.8% of the caregivers, in whom the sociodemographic characteristics were not different than the rest except for relation to the care recipient, where the spouse affected by psychiatric morbidity were 29.5% compared to 18% of those without psychiatric symptoms .
On comparing caregivers with psychiatric morbidity with those without psychiatric symptoms, significantly higher proportion of those with psychiatric morbidity had an older relative who needed care much of the time , and longer duration of care could contribute to 33% increase in risk of depression , as 40–79 of weekly care hours are predictor of depression in the caregiver . That agrees with our results that showed significant relationship between duration of caregiving and developing depression and anxiety in caregivers.
Relation between psychiatric morbidity and clinical characteristics of dementia patients
In the current study, there was a significant relation between severity of dementia, higher ADL and IADL impairment, behavioral and psychological symptoms of dementia, and increased level of psychiatric morbidity among caregivers. The severer the symptoms of dementia and the longer the duration of care, the more the depression and anxiety in the caregiver . Impaired ADL and hallucination are risk factors for depression .
A recent study  found that care provider’s psychiatric morbidity is associated the most with the severity of behavioral and mental disturbances in the care recipients, rather than the type of such disturbance. In a systematic review  of studies of relation between patient’s behavioral problems and caregiver’s burden and depression, 19 groups of recipient’s symptoms were identified to negatively impact the caregiver and contribute to their depression; however, no single cluster of symptoms was found to be conclusively accountable . The only exception was the patient’s depression, which could be the most consistent component of the dementia psychiatric and behavioral symptoms that drive higher caregiver depression [50, 52]. Increased severity of dementia as assessed by MMSE, ADL, and IADL is associated with increased depression and anxiety : memory, movement, and perception deterioration associated more with stress, while behavioral symptoms associated with caregiver’s depression. Other studies found limited relation between ADL and cognitive functions of the patient and the caregiver providers’ burden and depression .
Predictors of psychiatric morbidity (depression and anxiety)
The predictors of caregiver depression and anxiety in our study were found to be longer hours of caring, caregiver burden, higher scores on GHQ and lower scores of MMSE of demented patients. Some other studies included our predictors in addition to others as younger age of patient, the recipient’s lower level of education, two or more ADL dependence, and behavioral disturbance, particularly angry or aggressive behavior, besides caregiver low income, the relationship to the patient, hours spent caregiving, and functional dependence . Comparing predictors of depression and predictors of anxiety showed care recipient ADL impairment, living with the patient, being a female caregiver, reporting a poorer quality of relationship, and caregivers reporting their health as being poor all predicted anxiety disorder, comparatively, irritability, caregivers reporting poor health, and a poorer quality of relationship with the caregivers’ predicted depression .
Predictors of caregiver burden
The predictors of caregiver burden in our study were impairment of activities of daily living or instrumental activities of daily living and higher scores of GHQ. Proposing several models to predict caregiver’s burden, Clyburn et al.  found that higher behavioral disturbance, lower level of support to the caregivers, and non-institutionalized patients were perceived as higher burden leading to elevated rates of depression. Regression analysis age of caregiver, self-reported health status, and duration of care were positively associated with caregiver burden, while self-reported income had negative association . The same study found no association between number or type of impairment in ADL and caregiver burden. In a study to predict caregiver burden from ADL , the researchers differentiated between caregiver reported and observed ADL. They found that although the ADL reported by the caregiver is strongly correlated with their burden, the performance-based ADL showed weak association. This might explain our results, as we collected our ADL data from the relatives of the patients.
Strength and limitation
Our study is one of the fewest Egyptian studies that investigated the psychological well-being of dementia caregivers. This study illustrates a clear view of the most prevalent psychiatric morbidity in this population and their predictors.
The present study has some limitations, like small sample sizes and restricted inclusion criteria to the patients and families that accepted the participation in the study may limit the generalizability of the study. However, as the sample has been recruited from one of the largest centers that serve greater Cairo, this might help to some extent in randomization and variability of the selected sample.
Future research must continue to integrate family interventions into routine clinical settings for diagnosis and management of patients with dementia and to provide long-term follow-up studies.