Mood stabilizers for bipolar disorder
Valproate/divalproex, lamotrigine, carbamazepine, oxcarbazepine, and second-generation antipsychotics are the mood stabilizers used for bipolar disorder when lithium is ineffective, poorly tolerated, or contraindicated. Valproate treats acute mania, mixed episodes, and rapid cycling with an oral loading dose; lamotrigine, titrated slowly to limit serious rash, treats bipolar depression and maintenance but not acute mania; carbamazepine is second-line, limited by agranulocytosis.
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What this article covers
- Overview
What this covers: the non-lithium mood stabilizers, valproate (divalproex sodium), carbamazepine, oxcarbazepine, lamotrigine, and the second-generation antipsychotics (SGA); lithium is the reference first-line agent, covered separately.
- Epidemiology
Divalproex, the default alternative to lithium: first-line for rapid-cycling bipolar disorder (4 or more mood episodes per year) and mixed episodes.
- Risk factors
Renal impairment: lithium is renally cleared and relatively avoided with reduced renal function, favoring one of these agents.
- Pathophysiology
Valproate: blocks voltage-gated sodium channels and increases gamma-aminobutyric acid (GABA) concentrations; the mechanism behind its mood-stabilizing effect is not established.
- Clinical features
Acute mania, a mixed episode, or rapid cycling (4 or more episodes per year), valproate/divalproex first: the anticonvulsant of choice, given as a loading strategy; lithium is less reliable in this pattern.
- Differential diagnosis
Lithium: the reference first-line stabilizer for classic euphoric mania and maintenance, preferred when renal function is normal and the course is not rapid-cycling or mixed; needs trough level…
- Diagnosis
First, confirm the underlying diagnosis: bipolar I or bipolar II disorder is established clinically, using the manic or hypomanic episode symptom-count-plus-duration criteria, before any of these agents is chosen.
- Management
First, establish the episode type and pole: the agent differs for acute mania/mixed episode, acute bipolar depression, and maintenance.
- Complications
Valproate: hepatotoxicity, pancreatitis, and hyperammonemia are the serious effects driving its monitoring; teratogenic, causing neural tube defects, cardiac defects, cleft palate, and skeletal…
- Prognosis
Valproate for acute mania: effective for manic and mixed episodes, though the mechanism behind its mood-stabilizing effect is not established.
- Prevention
Valproate and carbamazepine monitoring intervals: periodic CBC/platelets and LFTs for both; add a serum ammonia level for valproate if encephalopathy develops, and periodic bone density testing with…
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Related articles
- Lithium
Lithium carbonate is the reference mood stabilizer for bipolar disorder, first-line for acute mania and long-term maintenance, and the only mood stabilizer credited with reducing suicide risk. Dosing is titrated to a trough serum level, targeting 0.8 to 1.2 mEq/L for acute mania and 0.6 to 1.0 mEq/L for maintenance. Its narrow therapeutic index and near-total renal clearance make dehydration, renal impairment, and interacting drugs the leading triggers of toxicity, which is treated with isotonic fluids and, when severe, hemodialysis.
- Bipolar I disorder
Bipolar I disorder is a chronic mood disorder defined by at least one manic episode lasting a week or requiring hospitalization, with three or more DIG FAST symptoms causing marked impairment. Diagnosis is clinical after substances and medical mimics are excluded. Acute mania is treated with lithium or valproate, often with an atypical antipsychotic, and most patients need lifelong mood-stabilizer maintenance.
- Bipolar II disorder
Bipolar II disorder requires at least one hypomanic episode (elevated or irritable mood for 4 or more consecutive days without marked impairment, psychosis, or hospitalization) plus at least one major depressive episode, and no lifetime history of a full manic episode; first-line treatment is lithium with careful avoidance of unopposed antidepressants.
- Cyclothymic disorder
Cyclothymic disorder is a chronic bipolar-spectrum illness with numerous hypomanic-range and depressive-range periods that never meet full episode criteria for at least 2 years (1 year in children). Diagnosis is clinical; first-line treatment is cognitive behavioral therapy (CBT), with divalproex sodium started when functioning is impaired.
- Major depressive disorder
Major depressive disorder is a mood disorder defined by 5 or more of 9 major depressive episode symptoms, including depressed mood or anhedonia, present nearly every day for at least 2 weeks and causing significant functional impairment. Diagnosis is clinical, screened with the Patient Health Questionnaire. First-line treatment is cognitive behavioral therapy, a selective serotonin reuptake inhibitor (SSRI) such as sertraline, or both, escalating to augmentation, esketamine, or electroconvulsive therapy for refractory or acutely suicidal presentations.