Study of Psychiatric Disorders in Patients with Psoriasis attending Outpatient Department in a Tertiary Hospital

The neuro-immuno-cutaneous endocrine model explains the mind-body connection. This model explains how many inflammatory dermatoses are triggered or exacerbated by stress factors. These conditions are called psychophysiological skin diseases. Psoriasis is a common psychophysiological skin disease. It affects 2-4% of the population worldwide and involves multiple systems in the body. The rates of psychiatric comorbidities are high in psoriasis, but still, they are not given due attention which leads to an increase in morbidity and mortality in the long run. This study intends to uncover the psychiatric comorbidities in psoriasis patients. In this study, the prevalence of psychiatric disorders was investigated among 104 patients with psoriasis. Following rating scales were used; Hamilton rating scales for depression and anxiety, Presumptive stressful life event scale, Beck scale for suicidal ideation, and Dermatology life quality index. The prevalence of psychiatric disorders in Psoriasis patients was found to be 66.35%. Among the psychiatric disorders, 29.8 % were dependent on substances, 18.27% were found to be suffering from depression,15.38 % with anxiety disorder and 2.88 % with psychotic disorders. Psoriasis has a high prevalence of psychiatric morbidity.


INTRODUCTION
Psychodermatology or psychocutaneous medicine focuses on the relationship between psychiatry and dermatology, which deals with the study of the influence of psychosocial stress in the exacerbation and chronicity of skin illness. 1 Both physical agents and psychosocial stress factors are linked with the natural history of several skin diseases, psoriasis being one of them.
Psoriasis is a chronic inflammatory autoimmune disorder that is associated with both genetic and environmental factors. It affects 2-4% of the population worldwide and involves multiple systems in the body. 2 The etiopathogenesis of psoriasis-psychological stress relationship includes peripheral nervous system pathways, Hypothalamic Pituitary Adrenal (HPA) axis, Sympatheticadrenal-medullary (SAM) system, and immune mediated pathways. Most studies of the neuroendocrine response to stress in psoriasis have demonstrated a blunted HPA axis cortisol response and a heightened sympathetic response to a stressor. 2 Stress is a trigger and an exacerbating factor in the pathogenesis of psoriasis. 3 In the last few decades, studies have pointed out the various mental disorders associated with psoriasis. 4 Even though the rates of psychiatric comorbidities are high in patients with psoriasis, scant attention is paid to psychiatric comorbidities that affects the patients. 5 Associated psychiatric comorbidity is likely to be caused by the complex interplay of stress, physical discomfort, and possible disfiguration inherent to psoriasis as well as an emotional response to the condition mediated by the patient's personality, emotional/cognitive state, and other social factors. 6 Other contributory factors might be a heightened proinflammatory state associated with psoriasis as well as the patient's emotional reaction to the effects of psoriasis on the quality of life. 2 If they are not taken care of, these comorbidities have a bearing on treatment improvement of primary dermatologic condition, including psoriasis as well. 7 The main aim of this study was to evaluate the psychiatric disorders in patients with psoriasis. The relationship between stress and psoriasis, and the quality of life among psoriasis patients was also studied.  9 Hamilton Anxiety Rating Scale (HAM-A), 10 Dermatology Life Quality Index (DLQI), 11 Beck Scale for Suicidal Ideation (BSSI), 12 and PSLE 13 were applied to assess the respective domains. A total of 104 patients with psoriasis were included in the study. Data was entered in MS Excel. Statistical analysis was done by SPSS 16. T-test and Chi-square test were applied to determine the association, where p-value less than 0.05 was considered statistically significant.  (Table 3).     21 The differences in results could be due to the different populations with different cultural practices.

RESULTS
Svanstrom et al reported 17-30% of patients with plaque psoriasis had alcohol use disorders. 22 This is similar to a study reported by Mahajan et al. 23 Other studies showed alcoholism in 12-18% psoriasis patient. 6,24,25 Our study also reported similar findings.
Depression is also a common comorbid disorder with a prevalence of around 19-60% in different studies. 5,6,[25][26][27][28][29] In our study, depression was reported in 18.3% of patients, which is similar to the above-mentioned study. In our study, mild depression was seen in 2.9% patients, moderate depression in 8.7%, and severe depression in 6.7%. Kumar et al, 26 in their study, identified 68.0% with mild, 18.0% with moderate, and 4.0% with severe depression. Disfigurement, stigmatization, high scores on pruritis, and pain are considered the contributory factors to depression.
Suicidal ideations are found in around 2-11% patients, mostly in the context of depressed mood and anhedonia 18,24,21,30 Similar finding was reported in our study where 10.6% reported suicidal intent, which was low in 6.7% and medium in 3.9% of patients. None of the patients reported high intent or suicidal attempts. Psoriasis may lead to anxiety and vice versa. The prevalence of anxiety disorders in patients with psoriasis, based on the systematic review of studies, was found to range from 7 to 48.0% 31 Other studies also report a prevalence within this range. 6,7,17,18,26,32,33 Anxiety disorders were identified in 15.4% in our study which is similar to the above findings.
Anxiety disorders have been reported in various studies where, adjustment disorders range from 15-62%. 6,18 In our study, 3.8% were diagnosed with adjustment disorders, which is similar to a study reported from Himachal Pradesh, 34 where 2.4% of patients were diagnosed with adjustment disorders. Generalized Anxiety Disorder (GAD) was reported to be 9-13% in various studies. 6,29 Kashyap et al 34 reported 2.4% patients with GAD. Only 1.0% of cases of GAD were diagnosed in this study. Mixed anxiety depression was reported 13.7% by Biljan et al, 6 which is diagnosed in 1.0% of patients in this study. Obssessive Compulsive Disorder (OCD) and Social phobia were seen in 1.0% each in this study. Social phobia was reported to be seen in 1.6% of patients by Kashyap et al. 34 The difference in results could be due to the different populations under study, different methods of reporting used, or under-reporting of symptoms by the patients.
In this study, Anxiety NOS was reported in 7.7% of patients; the highest among the different anxiety disorders. Amongst patients diagnosed with anxiety, 9.6% had mild, 4.8% mild to moderate, and 1.0% severe anxiety symptoms.
Kumar et al 26 reported 52.0% of patients with mild, 36.0% with mild to moderate, and 12.0% with moderate to severe anxiety.
Various studies have shown the evidence of a relationship between psychotic symptoms and psoriasis, which has been reported to range from 2-35%. 16, Similar to these studies, psychosis was diagnosed in 2.9% of patients in our study.
Sleep impairment in psoriasis could be due to pruritis, pain, or low mood. 35  Psoriasis is a common psychophysiological skin disease with a major impact on patient's QOL. It was reported that patients with psoriasis suffer from similar deterioration in health related QOL as patients with cancer and CV disease. 4 Seventy-nine percent of patients stated that psoriaisis had a negative impact on their QOL. 25 In our study, 95.2% of patients reported psoriasis affected their QOL. Among them, in 20.2% patients, psoriasis had an extremely large effect on patient's QOL, and in 37.5% of patients, a very large effect on QOL respectively. A study from Jammu, 37 stated that 24.3% of patients with psoriasis had a very large effect on the QOL, and 4.0% had an extremely large effect on QOL.
Singh et al, 28 in their study, reported that the mean scores across each heading of DLQI and total were significantly more in the group with comorbid psychiatric disorders. In our study, in 27.5% of psoriasis patients with the comorbid psychiatric disorder had an extremely large effect on patient's life as compared to 20.2% patients diagnosed only with psoriasis, though the results are not statistically significant.
Patients with psoriasis have reported more stressful life events in comparison to control. Stressful life events are both a cause and aggravating factor for psoriasis. 21 In >50% patients, psychological stress exacerbates psoriasis. 2 Very high rates of stressful life events (43-73.6%) have been reported to be preceding the onset of illness in various studies. 21,25,38,39 In our study, 59.6% of the patients reported stressful events before the onset of illness. Among them, 72.6% stated undesirable life events preceding the illness. A similar findings noted in another study 21 in which 73.6% of patients had a negative life event 12 months before the onset of symptoms.
In Conclusion, this study showed that psoriasis patients have a high degree of psychiatric disorders. Therefore, psychiatric consultation of all psoriasis patients is highly recommended.

Limitations:
Patients with pre-existing psychiatric disorders are also at a high risk of psoriasis, which couldn't be included here. This was only a cross sectional study, hence not representative of the population.