Mood stabilizer

A mood stabilizer is a psychiatric medication used to treat mood disorders characterized by intense and sustained mood shifts, typically bipolar disorder.

Uses

Used to treat bipolar disorder,^[1] mood stabilizers suppress swings between mania and depression. Mood-stabilizing drugs are also used in borderline personality disorder.^[2] and Schizoaffective disorder.

Examples

The term "mood stabilizer" describes an effect not a mechanism. More precise terminology is used to classify these agents.

Drugs commonly classed as mood stabilizers include:

Anticonvulsants

Many agents described as "mood stabilizers" are also categorized as anticonvulsants. The term "anticonvulsant mood stabilizers" is sometimes used to describe these as a class.^[3] Although this group is also defined by effect rather than mechanism, there is at least a preliminary understanding of the mechanism of most of the anticonvulsants used in the treatment of mood disorders.

• Valproic acid (Depakene), divalproex sodium (Depakote), and sodium valproate (Depacon, Epilim) – Available in extended release form. This drug can be very irritating to the stomach, especially when taken as valproic acid. Liver function and CBC should be monitored.
• Lamotrigine (Lamictal) – Particularly effective for bipolar depression. Usual dose is 100–200 mg daily, which can be built up by 25 mg every 2 weeks.^[4] The patient should be monitored for signs and symptoms of Stevens–Johnson syndrome, a very rare but potentially fatal skin condition.
• Carbamazepine (Tegretol) – CBC should be monitored, as carbamazepine can lower white blood cell count. Therapeutic drug monitoring is required. Carbamazepine was approved by the US Food and Drug Administration as a bipolar disorder treatment in 2005, but had been widely used previously.
• Oxcarbazepine (Trileptal) – Oxcarbazepine is not FDA approved for bipolar disorder. Still, it appears to be effective in about one-half of patients with bipolar disorder and be well tolerated.^[5]

Gabapentin (Neurontin) is not FDA approved as a treatment for bipolar disorder. Randomized controlled trials suggest that Gabapentin is not an effective treatment, but many psychiatrists continue to prescribe it, it is reported because of positive but "low-quality" literature reviews.^[6] Topiramate (Topamax) is not FDA approved for bipolar disorder, either; and a 2006 Cochrane review concluded that there is insufficient evidence on which to base any recommendations regarding the use of topiramate in any phase of bipolar illness.^[7]

Other

• Lithium – Lithium is the "classic" mood stabilizer, the first to be approved by the US FDA, and still popular in treatment. Therapeutic drug monitoring is required to ensure lithium levels remain in the therapeutic range: 0.6 or 0.8-1.2 mEq/L (or millimolar). Signs and symptoms of toxicity include nausea, vomiting, diarrhea, and ataxia.^[8] The less common side-effects of using lithium are blurred vision, slight tremble in the hands, and a feeling of being mildly ill. In general, these side-effects occur in the first few weeks after commencing lithium treatment. These symptoms can often be improved by lowering the dose.^[9]
• Some atypical antipsychotics (risperidone, olanzapine, quetiapine, and ziprasidone) also have mood stabilizing effects^[10] and are thus commonly prescribed even when psychotic symptoms are absent.^[10]
• It is also conjectured that omega-3 fatty acids may have a mood stabilizing effect.^[11] Compared with placebo, omega-3 fatty acids appear better able to augment known mood stabilizers in reducing depressive (but perhaps not manic) symptoms of bipolar disorder; additional trials would be needed to establish the effects of omega-3 fatty acids alone.^[12]

Sometimes mood stabilizers are used in combination, such as lithium with one of the anticonvulsants.

Relationship to antidepressants

Most mood stabilizers are purely antimanic agents, meaning that they are effective at treating mania and mood cycling and shifting, but are not effective at treating depression. The principal exceptions to that rule, because they treat both manic and depressive symptoms, are lamotrigine and lithium carbonate. While an antimanic agent such as valproic acid or carbamazepine cannot treat depression directly as the former two drugs can, it is widely thought to help ward off depression in bipolar patients by keeping them out of mania and, thus, preventing their moods from cycling.

Nevertheless, an antidepressant is often prescribed in addition to the mood stabilizer during depressive phases. This brings some risks, however, as antidepressants can induce mania, psychosis, and other disturbing problems in bipolar patients — in particular, when taken alone, but sometimes even when used with a mood stabilizer. Antidepressants' utility in treating depression-phase bipolar disorder is unclear.

Mechanism

Most mood stabilizers are anticonvulsants, with the important exception of lithium, which is the oldest and best-known mood-stabilizing drug.

One possible downstream target of several mood stabilizers such as lithium, valproate, and carbamazepine is the arachidonic acid cascade.^[13]

See also

• ATC code N03
• Treatment of bipolar disorder

References