Underutilization of Lithium
Despite widespread knowledge of lithium’s antisuicidal effects, it is underutilized as a mood stabilizer in the US.18 There are various modifiable barriers that impact the prescribing as well as use of lithium. Clinicians may not be fully aware of lithium’s antisuicidal properties and may also have a low level of confidence in patients’ likelihood of adherence to laboratory monitoring.18,19 Due to the narrow therapeutic index of lithium, the consequences of nonadherence to monitoring can be dangerous, which may deter mental health professionals from prescribing this antisuicidal agent. At MEDVAMC, only 72.4% of patients with a lithium prescription had a lithium level drawn within a 6-month period. This could be attributed to patient nonadherence (eg, the test was ordered but the patient did not go) or clinician nonadherence (eg, test was not ordered).
With increased clinician education as well as clinics dedicated to lithium management that allow for closer follow-up, facilities may see an increased level of comfort with lithium use. Lithium management clinics that provide close follow-up may also help address patient-related concerns about adverse effects and allow for close monitoring. To facilitate lithium monitoring at MEDVAMC, mental health practitioners and pharmacists developed a lithium test monitoring menu that serves as a “one-stop shop” for lithium baseline and ongoing test results.
In the future, we may study the impact of this test monitoring menu on lithium prescribing. One may also consider whether lithium levels need to be monitored at different frequencies (eg, less frequently for depression than bipolar disorder) depending on the diagnoses. A better understanding of the necessity for therapeutic monitoring may potentially reduce barriers to prescribing for patients who do not have indications that have a recommended therapeutic range (eg, bipolar disorder).
Lithium Adherence
A primary patient-related concern for low lithium utilization is poor adherence. In this sample, 71 patients (72.4%) were considered fully adherent. This was higher than the rate of 54.1% reported by Sajatovic and colleagues in a study evaluating adherence to lithium and other anticonvulsants in veterans with bipolar disorder.20 Patients’ beliefs about medications and overall health as well as knowledge of the illness and treatment may impact adherence.21 The literature indicates that strategies such as cognitive behavioral therapy (CBT) and didactic lectures positively impact patients’ attitudes about lithium, which ultimately influences adherence.21-23 Involving a family member or significant other in psychotherapy may also improve lithium adherence.21 Specifically in the VA, to address knowledge deficits and improve overall adherence, the Lithium Lab Monitoring Dashboard could be used to identify and invite new lithium starts to educational groups about lithium. These groups could also serve as lithium management clinics.
Limitations
There were several limitations to this study. This was a single-site, retrospective chart review with a small sample size. We studied a cross-section of veterans with only active prescriptions, which limited the sample size. The results should be interpreted cautiously because < 40% of patients who had a level drawn were in the therapeutic range. Patients whose lithium levels were outside of the therapeutic range may have not been fully adherent to the medication. Further analysis based on reason for lithium prescription (eg, bipolar disorder vs depression vs aggression/impulsivity in PTSD) may be helpful in better understanding the results.
Additionally, while we collected data on concomitant mood stabilizers and antipsychotics, we did not collect data on concurrent antidepressant therapy and only 4% of patients were on lithium monotherapy. Data regarding veterans undergoing concurrent CBT during their lithium trial were not assessed in this study and could be considered a confounding factor for future studies. We included any Veteran Crisis Line call in our results regardless of the reason for the call, which could have led to overreporting of this suicidality marker.
Given its small sample size, this study should be considered as hypothesis-generating. Further studies are needed to address lithium’s antisuicidal effects in specific diagnoses (eg, PTSD, anxiety, schizoaffective disorder) to better understand its place in therapy. Studies evaluating the relationship between dosing and suicidality may help provide insight into whether the antisuicidal effect of lithium is dose-dependent and whether a specific dose range rather than a therapeutic level should be targeted for antisuicidal purposes.
Conclusions
People treated for an affective disorder have a 30-times greater risk of suicide than do those in the general population; however, as lithium can reduce the risk of suicide and self-harm, it should continue to have an important role in clinical practice.24 At MEDVAMC, we observed a statistically significant reduction in hospitalization for suicide attempts and suicidal ideation in veterans prescribed lithium following nonfatal suicide behavior and suicidal ideation. Prospective randomized placebo-controlled studies are needed to better understand lithium’s antisuicidal effects.