¹Universidad de La Sabana, Cundinamarca, Chía, Colombia, ²Deakin University, Burwood, Melbourne, Australia

Background: Bipolar disorder is characterized by manic (or hypomanic) and depressive episodes, which can be debilitating for the patient, increasing the likelihood of comorbid illness, substance use disorders, and suicidal behavior. According to the World Health Organization (WHO), it is estimated to affect 1 in 200 people worldwide, with Colombia having one of the largest treatment gaps, exceeding 80%.

Aims & Objectives: Lithium is an effective first-line treatment for manic episodes and maintenance in bipolar I disorder but is characterized by a narrow therapeutic index (0.4 to 1.0 mEq/L). Low blood lithium concentrations are associated with a decreased therapeutic effect, while high concentrations are associated with a risk of toxicity. For patient safety, individuals receiving this medication must follow monitoring protocols to measure the blood lithium concentration. This monitoring requires patients to travel to healthcare facilities for blood sampling and appointments with physicians. For many patients in developing countries, like Colombia, particularly those living in rural areas, access to this type of treatment and monitoring is limited, resulting in people being untreated or treated with less effective therapies. Therefore, the objective of our research is to develop a small, portable device for home and point-of-care monitoring of blood lithium concentrations.

Method: Our research addresses these challenges and offers a significant advance in lithium treatment. Our therapeutic drug monitoring (TDM) device will reduce the TDM burden for patients receiving lithium, provide rapid measurements of lithium blood concentrations, and make treatment with this essential medicine available to those who need it, regardless of where they live. Our international collaboration will produce a small, portable therapeutic drug monitoring device for lithium patients that meets the following parameters: low cost, sensitivity, accuracy, precision, and ease of use.

Results: In our preliminary investigations, we modified different carbon and gold ink electrodes with lithium oxides to determine the presence of lithium in aqueous solutions using cyclovoltametry and chronoamperometry. We observed that the device can detect lithium concentrations below the drug's therapeutic range and that these results are reproducible over time. These measurements will lay the foundation for the development of a portable device to measure lithium levels in patients' blood.

Discussion & Conclusions: Tasks still to be completed include further optimization of the biosensor, integration of all components of the device and optimization of the assembled device. Implementation of science and scalability research to ensure that the device is fit for purpose is in progress. This type of portable equipment will be a significant advancement in the treatment of people with bipolar disorders, regardless of their physical or socioeconomic circumstances. The Rafaelsen Prize would be a great opportunity to share our research globally and learn even more about this condition, which we are working to address in the field of mental health.