Treating Bipolar Disorder
There are two major types of bipolar disorders: (i) bipolar I disorders are associated with patients who have episodes of sustained mania, and often experience depressive episodes, and (ii) bipolar II disorders are associated with patients who have one or more major depressive episodes, with at least one hypomanic episode. Good prognosis in bipolar disorder means fewer episodes or faster recovery. It is important to distinguish between symptoms of bipolar disorder and those of depression, since the treatment of these two diseases are different.
Interestingly, most clinical trials focus on treatment for bipolar I disorder, despite the fact that bipolar II disorder is more prevalent than bipolar I. The treatment of bipolar disorder is based on the stage of illness and often classified into 3 phases:
- Acute phase of treatment: In this phase, the main objective is to contain the symptoms and to make sure that the patient is safe from suicidal risk and high-risk behaviors. Patients might be hospitalized to reduce the severity of symptoms.
- Continuation phase: The objective of this phase is to reach full remission of symptoms and restore the patient’s ability to function
- Maintenance phase : The objective of this phase is to maintain remission.
The most common ways of treating bipolar disorder - acute mania or hypomania - include lithium carbonate, anticonvulsants, antipsychotics, and benzodiazepines. The typical response rates for these treatments are 50-60%. More specifically, meta-analysis of randomized clinical trials indicates that 70% of patients using lithium have their symptoms partially reduced. Valproate is another medication used for treating manic symptoms. The first-line therapy for acute depression in patients with bipolar disorder is lithium or lamotrigine.
The length of an episode varies between several weeks to several months and depends on the type of episodes. Mixed episodes tend to be longer and manic episodes tend to be shorter. The length of an episode also depends on the response of the patient to treatment.
Outcome measures of treatment can only be accessed after years. Marneros and Brieger (2005) concluded that risk factors at baseline such as age of onset, gender, socioeconomic status are not predictive for outcome. A high number of past episodes seem to predict a high number of future episodes.
Efficacy of divalproex vs lithium and placebo in the treatment of mania. The Depakote Mania Study Group. Bowden CL; Brugger AM; Swann AC; Calabrese JR; Janicak PG; Petty F; Dilsaver SC; Davis JM; Rush AJ; Small JG; et al. Journal of the American Medical Association. 2004 Mar 23-30; 271(12):918-24.
A placebo-controlled 18-month trial of Lamotrigine and lithium maintenance treatment in recently depressed patients with bipolar I disorder,Calabrese JR, Bowden CL, Sachs G, Yatham LN, Behnke K, Mehtonen OP, Montgomery P, Ascher J, Paska W, Earl N, DeVeaugh-Geiss J; Lamictal 605 Study Group.The Journal of Clinical Psychiatry ISSN 0160-6689 2003, vol. 64, no 9, pp. 1013-1024.
Relapse and Impairment of Bipolar Disorder, MJ Gitlin, J Swendsen, TL Heller, C Hammen - American Journal of Psychiatry, 2005; 152:1635-1640