Bipolar disorders O004 Lithium-associated hypothyroidism: Reversible after lithium discontinuation? I. Lieber 1 *, M. Ott 2 , L. Öhlund 3 , R. Lundqvist 4 , M. Eliasson 5 , M. Sandlund 6 and U. Werneke 3 1 Sunderby Research Unit, Deparment of clinical science, division of psychiatry, Luleå, Sweden; 2 Medicine, Umeå Univeristy, Department of Public Health and Clinical medicine, Umeå, Sweden; 3 Sunderby Research Unit, Umeå University, Deparment of clinical science, division of psychiatry, Luleå, Sweden; 4 Norrbotten Region, Reserach and Innovation Unit, Luleå, Sweden; 5 Department Of Public Health And Clinical Medicine, Sunderby research Unit, Luleå, Sweden and 6 Division Of Psychiatry, Umeå University, Department of Clinical Sciences, Umeå, Sweden *Corresponding author. doi: 10.1192/j.eurpsy.2021.231 Introduction: The association between lithium and thyroid dys- function has long been known. Yet it is not known whether lithium- associated hypothyroidism is reversible, once lithium treatment has been stopped. Objectives: To determine whether lithium-associated hypothyroid- ism was reversible in patients who subsequently discontinued lithium. Methods: Retrospective cohort study in the Swedish region of Norrbotten into the effects and side- effects of lithium treatment and other drugs for relapse prevention (LiSIE). For this particular study, we reviewed medical records between 1997 and 2015 of patients treated with lithium. Results: Of 1340 patients screened, we identified 90 patients with lithium-associated hypothyroidism who subsequently discontin- ued lithium. Of these, 27% had overt hypothyroidism at the time when thyroid replacement therapy was initiated. The mean delay from lithium start to thyroid replacement therapy start was 2.3 (SD 4.7) years. Fifty percent received thyroid replacement therapy within 10 months of starting lithium. Of 85 patients available for follow up, 35 (41%) stopped thyroid replacement therapy after lithium discontinuation. Six patients reinstated thyroid replace- ment therapy subsequently. Only one of these had overt hypothy- roidism, occurring 13 days after stopping lithium and 11 days after stopping thyroid replacement therapy. Conclusions: Lithium-associated hypothyroidism seems revers- ible in most patients, once lithium has been discontinued. In such cases, thyroid replacement therapy discontinuation could be attempted much more often than currently done. Based on the limited evidence of our study, we can expect hypothyroidism to recur early after discontinuation of thyroid replacement therapy if at all. Disclosure: MO: scient adv. board member Astra Zeneca Sweden; UW: educ. activities Norrbotten Region: Astra Zeneca, Eli Lilly, Janssen, Novartis, Otsuka/Lundbeck, Servier, Shire and Sunovion. All others: none. Keywords: lithium; adverse effects; bipolar disorder; hypothyroidism O005 The WHO-5 well-being scale and its correlation to depressive and manic symptoms among outpatients with bipolar disorder or unipolar depression S. Straszek 1,2 *, A.-E. Christensen 3 , R. Licht 2,3 , S. Østergaard 4,5 and R. Ernst Nielsen 2,6 1 Research And Treatment Programme For Bipolar Disorder, Psychiatry - Aalborg Úniversity Hospital, Aalborg, Denmark; 2 Department Of Clinical Medicine, Aalborg University, Aalborg, Denmark; 3 Unit For Psychiatric Research, Psychiatry - Aalborg University Hospital, Aalborg, Denmark; 4 Department Of Clinical Medicine, Aarhus University, Aarhus, Denmark; 5 Department Of Affective Disorders, Aarhus University Hospital - Psychiatry, Aarhus, Denmark and 6 Psychiatry, Aalborg University Hospital, Aalborg, Denmark *Corresponding author. doi: 10.1192/j.eurpsy.2021.232 Introduction: There is a lack of longitudinal studies of patients with bipolar disorder (BD) or unipolar depression (UD) in terms of psychological well-being as measured by the WHO-5 and the correlation to symptom scores. It is of interest to investigate whether the WHO-5 is useful in monitoring patients with mood disorders over time, as a tool in measurement-based care, and as a supplement to other psychometric measures. Objectives: In this study we investigate the correlation at baseline between the depressive symptom scores according to the 6-item Hamilton Depression Score (HDS-6) and the WHO-5 scores in outpatients treated for BD or UD. Furthermore, in patients with BD we investigate correlations between manic symptom scores accord- ing to the modified Bech-Rafaelsen Mania Scale (MAS-M) and the WHO-5 scores. Lastly, in patients with BD or UD, we investigate the correlations between endpoint-baseline change in WHO-5 and change in MAS-M and HDS-6. Methods: A longitudinal study of 200 outpatients diagnosed and treated for either BD or UD. Patients will be measured at baseline and at least four weeks later. Baseline data are presented as fre- quencies, means and standard deviations or medians with inter- quartile ranges as appropriate. All correlations are presented as scatter plots and a Spearman correlation analysis Results: The study is ongoing, but the results will be available for presentation at the EPA in 2021. Conclusions: The WHO-5 may represent a relevant outcome measure in the treatment of BD and UD. Disclosure: No significant relationships. Keywords: bipolar disorder; who-5; quality of life; unipolar depression O006 Higher illness burden is associated with reduced heart rate variability in bipolar disorder A. Ortiz 1 *, I. Husain 1 , P. Moorti 2 , M. Alda 3 , M. Sanches 1 and B. Mulsant 1 1 Department Of Psychiatry, University of Toronto, Toronto, Canada; 2 Mood Disorders, The Royal Ottawa, Ottawa, Canada and 3 Psychiatry, Dalhousie University, Halifax, Canada *Corresponding author. doi: 10.1192/j.eurpsy.2021.233 S76 Oral Communications https://doi.org/10.1192/j.eurpsy.2021.233 Published online by Cambridge University Press