Lamotrigine and lithium in primary care psychiatric consultation: adoption and adverse effects.

BACKGROUND: The Collaborative Care Model of psychiatric consultation in primary care has improved outcomes for unipolar depression, but bipolar depressions are challenging for providers and consultants. Although lamotrigine and lithium are both first line medications for bipolar depression, their use in primary care has been declining over the last decade. OBJECTIVE: Our project aimed to quantify the frequency of and adoption of recommendations for lamotrigine and lithium, and their adverse effects, in a Collaborative Care program. METHODS: Chart review. RESULTS: For 620 depressed adult patients (Public Health Questionnaire, 9-item ≥10), lamotrigine and lithium were recommended by psychiatric consultant for 35% and 26% of patients, respectively; and when recommended, were prescribed by primary care providers 50% and 32% of the time, respectively. Eighty-four percent of lithium dosages were 600 mg or less; average serum level 0.32 mEq/l. In follow-up up to 6 months, lithium was associated with no more weight gain than lamotrigine; but 12% of patients receiving lithium had thyroid stimulating hormone increases exceeding the upper limit of normal, occurring in an average of 32 days after the initial prescription. CONCLUSIONS: (i) In a Collaborative Care program of psychiatric consultation, recommendations for lamotrigine and lithium were very frequent. (ii) Adoption of these recommendations is variable, warranting further investigation. (iii) Like higher doses, low doses of lithium induced hypothyroidism (rapidly)-but not weight gain.

Depression is a common problem. One variation, bipolar depression, often does not respond well to antidepressants. But bipolar depression is hard to diagnose, especially in busy primary care clinics. With too few psychiatrists available, primary care providers have often had to treat bipolar depression themselves. To address this problem, in the USA a system of consultation ('Collaborative Care') has been developed that allows a remote psychiatrist to make treatment recommendations for patients based on data gathered by the primary care team. In this study of 620 patients with depression, we looked at how often psychiatric consultants recommended two medications for bipolar depression which tend to be underused: lamotrigine and lithium. We found that lamotrigine was recommended for one third of these 620 patients, and lithium for one quarter­much higher percentages than are routine in primary care of depression. But because either the providers or their patients were hesitant about these medications, actual prescriptions were fewer: 50% of the times when it was recommended for lamotrigine; 32% for lithium. Side effects were few. This study shows that psychiatric consultation leads to increased use of important medications for bipolar depression. Now we need a study to show it helps improve outcomes!

Bipolarity in a Collaborative Care Model Variation: Detection, Prevalence, and Outcomes.

OBJECTIVE: To assess the prevalence of bipolarity and its impact on clinical course, psychiatric consultants' diagnostic impressions and respective treatment outcomes were examined for patients with depression who were treated in a collaborative care model (CoCM) of psychiatric consultation. METHODS: Electronic records for 1,476 patients were reviewed for the presence of a mood disorder, which yielded 641 patients with complete data on several measures: the Composite International Diagnostic Interview, version 3.0 (CIDI); a questionnaire eliciting data on non-mania-related markers of bipolar disorder (family history, age of onset, course of illness, response to treatment); consultants' diagnostic impressions; and Patient Health Questionnaire-9 (PHQ-9) scores before and after consultation. RESULTS: Of referred patients, 97% were screened for bipolar disorder. A smooth distribution of scores on the CIDI was observed. Patients were divided into four groups on the basis of their CIDI scores (≥7, positive, or <7, negative) and on the consultant's recorded Impression (positive or negative for bipolarity). Of the study sample, 21% were CIDI positive (≥7), and 35% were Impression positive (sufficient bipolarity to guide treatment recommendations). All groups demonstrated equivalent decreases in PHQ-9 scores in the 6 months since consultation, including the potentially overdiagnosed group (CIDI negative, impression positive), which comprised 22% of the study sample. CONCLUSIONS: Universal screening for bipolarity in primary care is feasible in CoCM programs. Interpreting the data dimensionally is logical on the basis of the smooth distribution of CIDI scores. Such screening will yield high rates of bipolar disorder, much higher than previously reported. Offering treatment recommendations based on an impression of bipolarity to patients with negative CIDI results (<7) was not associated with outcomes worse than experienced by all other consultation patients. Multiple explanations of the latter finding are possible, warranting additional study.