To our best of knowledge, this is the first cross-sectional survey from Gaza to document the prevalence of undiagnosed depression among hypertensive patients. We found that the prevalence of undiagnosed clinical depression in our hypertensive population is almost higher than what is observed in Norway (6.2%) and South Africa (6%); and lower than in the US(44.9%), China (44.2%), Mexico (57.5%), Pakistan (40.1%), Croatia (29.6%) and Nigeria (26.7%). However, it was similar to that observed in Brazil (12.1%), Ghana (10.5%) and Netherlands (11.4%) [9, 21]. In addition, this prevalence was lower than the rate reported in a systematic review and meta-analysis (26.8%) which summarized the prevalence of depression among hypertensive individuals in 41 studies [9].
Unfortunately, very limited data is available from Arabic regional countries. One study from Saudi Arabia found a prevalence of 20.7% [22]. Still, no local prevalence was found from other parts of Palestine. Our study showed that the prevalence of depression among hypertensive patients was lower than the prevalence of patients with type two diabetic in the West Bank of Palestine (40%) [23]. One important issue that the prevalence of depression in this study would be underestimated because we have excluded the already known patients with history of depression or currently on antidepressant medications.
The associated factors found by multiple linear regression in this study were: age, number of antihypertensive medication, adherent status, health-care system support, patient-doctor relationship and perceived social support. Increasing age was found to be an associated factors with increase depressive symptom in other studies [21, 22, 24, 25], although, our results predicted a negative relationship between age and depressive status. An explanation of this could be related to the nature of aged people in Gaza, since they are more acceptance and adapted to their disease than younger adult.
However, gender and smoking [21, 22, 24, 26] found to be associated factors in previous studies, they did not reach statistical significant level in our study. Longer hypertension duration has been previously found to be significantly associated factor in an Indian study [26]; and was associated factor in our univariable analysis, although, it could not reach significant level in multivariable analysis. In addition, inline to what has been found on a systematic review [8], we found a negative relationship between depression and adherence to antihypertensive medications. Furthermore, statistical significant association with number of antihypertensive medication and depression was observed in our study, which was supported by previous findings [24, 27].
In this study we have investigated the relation of depression status with health-care system support, patient-doctor relationship and perceived social support. Interestingly, a positive relationship between depression and health-care system support was found. This could be explained by the frequent visit of the patient to the primary health care clinic, and his increased need to its supportive aids. On the other hand, it was a negative relationship with patient-doctor relationship and social support. It is highly believed to be negative relationship between depression and perceived social support since social support is a significant predictors of depression and hypertension treatment programs [28, 29].