Journal Article Annotations
2021, 1st Quarter
Annotations by J. Jewel Shim, MD
March, 2021
The finding:
Previous studies have established an association between major depressive disorder (MDD) and inflammation-mediated medical conditions such as cardiovascular disease and diabetes as well as certain inflammatory skin conditions, such as psoriasis. Some studies have posited that the relationship between depression and psoriasis may be bidirectional, while other study results have suggested that MDD may contribute to the onset of psoriasis. Moreover, there is also evidence that the use of antidepressants may mitigate inflammatory markers found in depression. The study investigators sought to examine whether this effect could extend to reducing the risk of developing psoriasis in a cohort of subjects with MDD treated with antidepressants.
Strength and weaknesses:
Strengths include large study size and longitudinal follow up, meticulous confirmation of an MDD diagnosis, and matched control group. The study authors used inverse probability of treatment weighting (IPTW) to minimize bias of comorbid inflammatory conditions and utilized time dependent statistical analyses (Cox proportional hazards) that could better establish a temporal relationship between antidepressant use and subsequent diagnosis (or lack thereof) of psoriasis. One major weakness is that the study did not account for the use of over-the-counter medications that could have affected the results. The generalizability of the results was also highlighted as a limitation, as the study subjects were almost exclusively drawn from one major ethnic group.
Relevance:
This is an interesting study that highlights the scope of the potential benefits of treatment with antidepressants in not only treating depression but also mitigating the development of other inflammation-mediated disease.
Type of study (EBM guide):
The finding:
Psoriasis and atopic dermatitis are immune-mediated, inflammatory dermatological disorders that have known psychosocial burdens and have been associated with depression. Suicidal thoughts, depression, and other psychiatric disorders have also been associated with systemic inflammation. Given these associations and prior studies suggesting a relationship between these skin disorders and suicidal thoughts and behaviors, this systematic review examined the rate of suicidal ideation and behavior among patients with psoriasis and atopic dermatitis compared to control subjects. The study authors found that psoriasis was significantly associated with higher rates of suicidal ideation and behaviors, while atopic dermatitis was only significantly linked to suicidal ideation, with a trend toward an association with suicidal behaviors.
Strength and weaknesses:
This study is a meta-analysis, but included studies were small and thus limited power. There was limited information regarding criteria for psychiatric diagnoses or substance us disorders that may have been associated with suicidal ideation/behaviors.
Relevance:
Awareness of the association between these immune system mediated skin disorders and suicidal thoughts/behaviors may guide C-L psychiatrists in their treatment planning and recommendations to consulting teams.
Type of study (EBM guide):
The finding:
Atopic dermatitis (AD) has previously been associated with higher rates of inflammation-mediated disorders such as diabetes, hypertension, and cerebrovascular diseases. These disorders are also considered to be risk factors for dementia. However, the direct relationship between AD and dementia has not been previously investigated. In this longitudinal cohort study, the investigators found a possible association between AD and the subsequent development of dementia, as compared to a cohort of matched control subjects.
Strength and weaknesses:
Strengths include the size of the study as well as a matched control group and longitudinal data. However, limitations relate to the database itself, as it did not include data prior to 1996 and thus no information regarding diagnosis of AD before this date was available. The authors pointed out that some of these subjects may have remitted AD and may have been erroneously included in the control group. In addition, the study analyses did not account for the use of antihistamine drugs, which are commonly used in AD and have also been found to have an association with a later diagnosis of dementia.
Relevance:
Knowledge of this potential association between AD and later development of dementia may guide C-L psychiatrists in developing treatment plans for patients who suffer from this skin condition.
Type of study:
Annotation (unstructured)The study authors posited a correlation between PTSD and the subsequent development of an autoimmune skin disease (ASD), mediated by the common denominator of inflammation. Based on previous studies, PTSD has been found to cause alterations in the immune system, mediated by stress. Similarly, ASDs can also be caused and exacerbated by stress. This study, using the National Health Insurance Research Database (NHIRD) in Taiwan, recruited subjects with a diagnosis of PTSD and randomly selected matched controls without PTSD and then followed them until theu received a diagnosis of ASD, the end date of study period, or withdrawal from the NHIRD. The investigators found a 3-fold higher risk of certain ASDs in the PTSD cohort compared to the control group, though not for all ASDs considered.
Type of study (EBM guide):
Cohort study