Association of hypothyroidism and clinical depression: systematic review and meta-analysis Key points Is there an association of hypothyroidism and thyroid autoimmunity with depression? Findings In this systematic review and meta-analysis of 25 studies including 348,014 participants, there was a moderate association of overt, and less subclinical, hypothyroidism with clinical depression; this association is stronger in women than in men. No statistically significant association was found between verified thyroid peroxidase antibody positivity and clinical depression. Meaning A strong connection between hypothyroidism and depression was not evident in this analysis; however, a possible dose-effect relationship should be further investigated, especially in women. Summary Importance Hypothyroidism is considered a cause or strong risk factor for depression, but recent studies provide conflicting evidence regarding the existence and extent of the association. It is also unclear whether the link is largely due to subsyndromal depression or whether it is true for clinical depression. Aim To estimate the association of hypothyroidism and clinical depression in the general population. Data sources The PubMed, PsycINFO, and Embase databases were searched from inception to May 2020 for studies on the association of hypothyroidism and clinical depression. Study selection Two reviewers independently selected epidemiological and population-based studies that provided laboratory or International Statistical Classification of Diseases and Related Health Problems diagnoses of hypothyroidism and diagnoses of depression according to operational criteria (e.g., Diagnostic and Statistical Manual of Mental Disorders or International Statistical Classification of Diseases and Related Health Problems) or cut-off points on established rating scales. Data extraction and synthesis Two reviewers independently extracted data and assessed studies according to the Newcastle-Ottawa scale. Summary odds ratios (ORs) were calculated in random-effects meta-analyses. Main results and measures The prespecified co-primary outcomes were the association of clinical depression with hypothyroidism or autoimmunity. Results Of 4350 articles screened, 25 studies were selected for meta-analysis, including 348014 participants. Hypothyroidism and clinical depression were associated (OR, 1.30 [95% CI, 1.08-1.57]), while the OR for autoimmunity was inconclusive (1.24 [95% CI, 0.89 -1.74]). Subgroup analyzes revealed a stronger association with overt than subclinical hypothyroidism, with ORs of 1.77 (95% CI, 1.13-2.77) and 1.13 (95% CI, 1. 01-1.28), respectively. Sensitivity analyzes resulted in more conservative estimates. In a post hoc analysis , the association was confirmed in women (OR, 1.48 [95% CI, 1.18-1.85]) but not in men (OR, 0.71 [95% CI, 0.40-1.25]). Conclusions and relevance In this systematic review and meta-analysis, the effect size of the association between hypothyroidism and clinical depression was considerably lower than previously assumed, and the modest association was possibly restricted to overt hypothyroidism and women. Autoimmunity alone may not be the determining factor for this comorbidity. |
Comments
The effect size for the correlation between hypothyroidism and clinical depression appeared significantly lower than previously thought, according to the results of a systematic review and meta-analysis published in JAMA Psychiatry .
The correlation may only exist between people with overt hypothyroidism and women.
"A 2018 meta-analysis reported a substantial association of clinical and subclinical depression with hypothyroid autoimmunity," Henry Bode, of the department of psychiatry and psychotherapy at the University of Cologne in Germany, and colleagues wrote. “With an odds ratio (OR) of 3.31, Siegmann [and his colleagues] estimated that each year, more than 20% of patients with autoimmune thyroiditis experience depression. "This meta-analysis has been criticized, for example, for its combination of population-based studies with results from outpatient clinics, with its bias toward the most severely affected patients."
Another meta-analysis showed a weak and non-significant link between hypothyroidism and depression (OR = 1.24); however, this meta-analysis of individual patient data used only six studies and was limited to subclinical hypothyroidism. Therefore, it is unclear if and how hypothyroidism is associated with clinical depression, Bode and his colleagues noted.
In the current study, we aimed to address this research gap by searching three databases from inception to May 2020 for epidemiological and population-based studies evaluating this potential association using ICD diagnoses of hypothyroidism. and depression diagnoses based on established operational criteria or cut-off points. rating scales. The association of clinical depression with hypothyroidism or autoimmunity served as prespecified co-primary outcomes.
The researchers included 25 studies , with a total of 348,014 participants , in the meta-analysis. They found an association between hypothyroidism and clinical depression (OR = 1.3; 95% CI, 1.08-1.57); however, the OR for autoimmunity was inconclusive (OR = 1.24; 95% CI, 0.89-1.74).
Based on subgroup analyses, there was a stronger association for overt than subclinical hypothyroidism, with respective ORs of 1.77 (95% CI, 1.13-2.77) and 1.13 (95% CI). , 1.01-1.28).
Sensitivity analyzes showed more conservative estimates. A post hoc analysis confirmed the association among women (OR = 1.48; 95% CI, 1.18-1.85) but not among men (OR = 0.71; 95% CI, 0.4-1.85). 1.25).
"It may be time to reconsider the paradigm of a strong connection between hypothyroidism and depression," Bode and colleagues wrote. “Results from other groups and our own findings indicate that the contribution of hypothyroidism to the depression pandemic is probably small. "This is good news for patients with hypothyroidism or, in particular, thyroid autoimmunity."
