Hydroxychloroquine increased psychiatric-like behaviors and disrupted the expression of related genes in the mouse brain

H Xu, XY Zhang, WW Wang, JS Wang

Preprint posted on 28 September 2020

Article now published in Frontiers in Pharmacology at

Hydroxychloroquine induces anxiety-like, but not depression-like behavior in mice

Selected by Nándor Lipták


Hydroxychloroquine (HCQ) is an anti-malaria and anti-inflammatory drug. HCQ can inhibit both B‐and T‐lymphocyte activation, NADPH-oxidase signaling and the production of inflammatory cytokines (An et al. 2015). Besides malaria, HCQ is used for treating autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis, and Sjögren syndrome, based on its anti-inflammatory actions. During the SARS-COV-2 pandemic, HCQ has been used as a treatment for COVID-19, although the efficiency of this therapy has not been supported by the results of clinical trials and studies (Meyerowitz et al. 2020). Moreover, HCQ therapy was associated with psychosis, anxiety and depression in the past. The goal of the present preprint was to investigate the behavioral effects of HCQ on non-infected, healthy male C57BL/6J mice, due to the recent usage of HCQ on healthy individuals as a preventive drug against SARS-COV-2.

In this preprint, the effects of HCQ on anxiety- and depression-like behavior and on the expression of three selected genes in mice were evaluated.


Key findings

HCQ was administrated intraperitoneally (i.p.) twice a day (every 12 hours) for 7 consecutive days. The immediate and lasting actions of two doses of HCQ on behavior and on the mRNA expression of brain-derived neurotrophic factor (BDNF), corticotropin-releasing hormone (CRH) and interleukin-1beta (IL-1β) were assessed 24 h and 10 days after the last injection, respectively.


HCQ evoked anxiety-like behavior in mice

Both in the immediate and lasting actions, high dose HCQ-group mice spent significantly less time in the open arms compared with the control group in the elevated plus maze (EPM) tests.


HCQ did not evoke depression-like behavior in mice

In the immediate experiments, high dose HCQ had no significant effect on immobility time compared to the control group in the forced swim test (FST). Interestingly, low dose HCQ reduced the immobility time significantly compared to the high dose group but not the control group. In the lasting experiments, neither doses of HCQ evoked any changes in depression-like behavior.


The effects of HCQ on the mRNA expression of BDNF, CRH and IL-1β in the hippocampus and amygdala

Both low and high dose HCQ significantly lowered the mRNA expression of CRH in the hippocampus after the chronic injection of the drug. BDNF mRNA expression was also reduced by high dose of HCQ in the hippocampus and the amygdala, both in the acute and chronic experiments. The mRNA expression of IL-1β was reduced by both doses of HCQ in the hippocampus, but not in the amygdala after the chronic HCQ treatment. IL-1β mRNA expression was significantly lower after the high dose HCQ treatment in the hippocampus, but not in the amygdala.


Why I liked this preprint

HCQ is currently not a treatment option for COVID-19, however, searching for therapies is a hot topic in the current pandemic, therefore, the actuality of the discussed preprint is indisputable. In addition, the statistical probes were well-chosen.


Questions for the authors

  1. The main source of CRH is the hypothalamic paraventricular nucleus (Keegan et al. 1994) and this nucleus has a prominent role in regulating hypothalamus-pituitary-adrenal axis (HPA). It is not clear, why hypothalamic CRH mRNA was not measured in the rt-qPCR experiments. In addition, the mRNA expression of arginine-vasopressin (AVP) and the receptors of CRH (CRHR1 and CRHR2) and AVP should be also measured. What was the reason of the selection of only three genes and two brain regions?
  2. In rodents, elevation in the plasma corticosterone indicates the activation of the HPA axis (Rivier et al. 1982). Mice were sacrificed after the behavioral tests; then why didn’t you measure plasma corticosterone concentration?
  3. Actually, it’s not a question, it’s a suggestion. Open arm time/total time rate (%) is more accurate and reliable parameter than open arm time (s) and closed arm time (s), because total time also includes the time spent in the center. Moreover, open arm entries/total entries (%) and total number of entries are also essential parameters of the EPM experiments. Figure 1C images are convincing, but the abovementioned parameters should be included.
  4. Low dose of HCQ reduced the immobility time in the forced swim test, while high HCQ dose exerted the opposite effect. Based on your data, HCQ high dose-treated mice did not exhibit depression-like behavior. What do you think about this controversial data?
  5. CRH mRNA expression was significantly lower in the hippocampus in HCQ-treated mice compared with the control group, both in the immediate and lasting experiments. These data indicate the hypo-activation of the HPA axis. I think your mRNA expression data should be interpreted more carefully.



An J., Woodward J.J., Sasaki T., Minie M. & Elkon K.B. (2015) Cutting Edge: Antimalarial Drugs Inhibit IFN-beta Production through Blockade of Cyclic GMP-AMP Synthase-DNA Interaction. Journal of Immunology 194, 4089-93.

Keegan C.E., Herman J.P., Karolyi I.J., O’Shea K.S., Camper S.A. & Seasholtz A.F. (1994) Differential expression of corticotropin-releasing hormone in developing mouse embryos and adult brain. Endocrinology 134, 2547-55.

Meyerowitz E.A., Vannier A.G.L., Friesen M.G.N., Schoenfeld S., Gelfand J.A., Callahan M.V., Kim A.Y., Reeves P.M. & Poznansky M.C. (2020) Rethinking the role of hydroxychloroquine in the treatment of COVID-19. Faseb Journal 34, 6027-37.

Rivier C., Brownstein M., Spiess J., Rivier J. & Vale W. (1982) In vivo corticotropin-releasing factor-induced secretion of adrenocorticotropin, beta-endorphin, and corticosterone. Endocrinology 110, 272-8.


Posted on: 14 October 2020 , updated on: 25 January 2021


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