The symptoms of bipolar disorder include profound mood swings, from depression to vastly overblown excitement, energy, and elation, often accompanied by severe irritability. Both children and adults are affected by the disorder.
Often the depressive phase of bipolar disorder is thought to be a period when the patient is at risk, but the manic phase has its own dangers. During the manic phase patients may risk harmful behaviors they might not otherwise engage in doing. For example, lavish spending sprees they cannot afford or pleasure-seeking behaviors with potentially serious health consequences.
Bipolar disorder patients are often at greatest risk from the time of the onset of the manic phase to the time when the medication for treatment takes effect. Unfortunately, it takes a considerable time for the medications often used for treatment to take effect because they do not directly enter into the brain, but rather work through a kind of chain reaction.
The objective of the medication is to block an enzyme thought to be over-active during the bipolar disorder’s manic phase. That enzyme is called protein kinase C (PKC), which regulates activities in brain cells.
In a recent 3 week study, researchers tested Tamoxifen as an alternative to treatment for the manic phase of bipolar disorder. Tamoxifen is best known as a treatment for breast cancer with the unusual property of also entering directly into the brain and blocking the enzyme PKC. This means that period between the onset of the manic phase of bipolar disorder and point when the PKC is under control is considerably shorter.
The good news is that in the 3 week study, 63% of the patients had reduced manic symptoms, while only 13% of the control group taking a placebo showed improvement. The bad news is that although tamoxifen was successful in reducing the symptoms of the bipolar disorder manic phase, by controlling the PKC enzyme, it also blocks estrogen (which is the property that makes it useful as a treatment in some cancers.)
Researchers feel that they have established a ‘proof of principle’ that shows targeting PKC directly is a feasible strategy for developing faster-acting medications for manic phase. Tamoxifen may not be the solution for treatment of bipolar disorder manic phase, but it has opened the door for further research.