Depression can be associated with other medical problems, such as diabetes, heart disease, cancer, RA and many other diseases. The relationship between depression and diseases is complicated. Depression can be worsened when with medical problems, while it also can increase physical disease. Depression makes difficulties for the patient to manage his disease. Many biological, psychological, and social factors can interact with the development of depression (
7). Serotonin monoamines, noradrenaline and dopamine are the main neurotransmitters in modulating the mood and behavior. Dysfunction in serotonergic and noradrenaline neurotransmitters and respectively dopamine decrease in depression. Anti-depressants that target serotonin and norepinephrine improve depression symptoms so there is a link between the interstitial nerves and depression. Dysfunction of other neurotransmitters such as gamma-aminobutyric acid (GABA) and glutamate, are also associated with depression. All of these neurotransmitters have a massive effect on the frontal cortex. Although functional impairment has been shown in the transmission of monoaminergic neurotransmitters in depression, it is not completely clear how this dysfunction develops in the nervous system (
8,
9). In a study by Sruamsiri et al. 500 RA patients with demographic characteristics were studied, 176 patients (35%) had depression symptoms but only 25 (5%) were officially diagnosed or physician visits them due to depression (
10). In the study done by Yilmaz et al., the prevalence of depression was reported 39.4% in RA patients (
11), other studies of the prevalence of depression in RA patient by da Costa et al. (
12), and Mella et al. (
13) were reported 33.7% and 53.2% respectively. Raafat et al. reported a study on of 50 SLE patients, 64% (32 patients) had showed one major symptom of depression according to depression questionnaire, while in the control group, 36% (16 out of 50) showed depression symptoms (
14). Schoenherr et al. reported that depressed mood correlates with the type of medicine taken by patients, for example corticosteroids increase the depression and this is consistent with our results. Therefore, physicians should consider depression among RA patients (
15).
5.2. Conclusions
We conclude that the prevalence of depression in RA, SLE and SSc patients were 61.63%, 73.52% and 60%, respectively. There was no significant association between depression and age of patients in RA and SLE. There was a significant association between depression and gender in patients with SLE and RA, but the total number of SSc patients who were included in the study were low so we could not evaluate it in them. There was no significant association between depression and educational level in RA patients, while there is a significant association between depression and educational level in SLE patients. There was a significant association between depression and quality of life in all patients enrolled in this study. There was a significant association between depression and social support in all patients enrolled in the study. There was a significant association between depression and corticosteroid consumption in all patients enrolled in the study. There was a significant association between the disease duration and depression in patients with RA and SLE, while there was no significant association between the duration of the disease and depression in patients with SSc. Due to the prevalence of depression in patients with rheumatic diseases such as RA, SLE and SSc the rheumatologists should pay special attention to depression among his patients and consult with a psychiatrist in such cases, also in the case of the medicines such as corticosteroids that cause depression, the rheumatologist should consider the psychiatrist’s advice. Finally, it is suggested to increase the information and the awareness of the patients and their family in psychological field and consider the role of family and friends in increasing the patients’ social supports in order to reduce the level of the depression and the risk of suicide among the patients.