Pramipexole in the Treatment of Refractory Depression in a Patient with Rapid Cycling Bipolar Disorder

Rapid cycling bipolar disorder: Literature review on pharmacological treatment illustrated by a case report on ketamine

INTRODUCTION

Rapid cycling bipolar disorder (RCBD) is defined as four or more affective episodes (depression, mania or hypomania) within 1 year. RCBD has a high point of prevalence (from 10% to 20% among clinical bipolar samples) and is associated with greater severity, longer illness duration, worse global functioning and higher suicidal risk, but there is no consensus on treatment option. The use of several pharmacological agents has been reported (levothyroxine, antipsychotics, antidepressants and mood stabilizers).

OBJECTIVE

The main objective of this review was to propose a critical review of the literature and to rank the pharmacological agent using a level of evidence (LEO) adapted from the Center for Evidence-Based Medicine, and to illustrate it with a case report on off-label intravenous ketamine.

METHOD

We conducted a review using the MeSH terms and keywords (bipolar [Title/Abstract]) AND (rapid [Title/Abstract]) AND (cycling [Title/Abstract]) AND (treatment [Title/Abstract]). Alexis Bourla and Stéphane Mouchabac screened 638 documents identified through literature search in Medline (PubMed) or by bibliographic references and 164 abstracts were then analyzed. Nonpharmacological treatments were excluded.

RESULT

Seventy articles were included in the review and divided into six categories: mood stabilizers, antipsychotics, hormonal treatments, ketamine and other pharmacological treatments.

DISCUSSION

Our review highlights the heterogeneity of the pharmacological treatment of RCBD and no clear consensus can emerge.

Antidepressant-like effect of pramipexole in an inflammatory model of depression

Pramipexole (PPX), a dopamine D2/3 receptor preferring agonist, is currently in use for the treatment of Parkinson's disease symptoms and restless legs syndrome. Recently, anti-inflammatory properties of PPX have been shown in an autoimmune model of multiple sclerosis, and case reports indicate PPX ameliorates depressive symptoms. Since peripheral inflammation is known to induce depression-like behavior in rodents, we assessed the potential antidepressant effect of PPX in an inflammatory model of depression induced by LPS. Repeated (daily for 7days, 1mg/kg, i.p.), but not acute (1h before LPS) treatment with PPX abolished the depression-like behavior induced by LPS (0.1mg/kg, i.p.) in the forced swim test, and the anhedonic behavior in the splash test. Interestingly, PPX per se decreased interleukin 1β levels and reversed LPS-induced increase in its content in mice hippocampus⋅ Repeated PPX treatment also prevented the increase in hippocampal levels of the 3-nitrotyrosine protein adducts induced by LPS. Haloperidol (0.2mg/kg, i.p.) and sulpiride (50mg/kg, i.p.) were unable to prevent the antidepressant-like effect of PPX in LPS-treated mice. Altogether, these results suggest that the observed antidepressant-like effect of PPX in LPS-treated mice may be dependent on its anti-inflammatory properties and may not be related to dopamine D2 receptor activation.