Mood stabilizing drugs: how do they work?

Imagine a roller coaster, the quintessential attraction of amusement parks. When you are on one of these and the climb begins, you may feel overwhelmed with exhilaration, but when you reach the top and the vehicle begins its descent, some people may feel fear, anxiety or desolation. Imagine this happening with your mood, day after day, week after week. Something similar occurs in bipolar disorder, in which manic episodes appear (phase up) and depressive episodes (phase down). Mood stabilizing drugs are used precisely to reduce mood swings in these patients.

Bipolar disorder (BD) is a serious mental disorder with a high suicide rate associated with it. The suffering of people affected by this disorder is immense, which is why before talking about treatment with mood stabilizing drugs, let’s proceed to define this clinical condition.

Bipolar disorder and stabilizing drugs

It is a chronic disease, i.e. it has no cure. For its diagnosis, there must have been at least one manic or hypomanic episode. The affectivity of these people is characterized by going through phases of hyperactivity or hyperexcitation (mania and hypomania), which alternate with periods of sadness and behavioral inhibition (depressive phases) and moments of clinical stability (euthymia). Additionally, people with bipolar disorder may have mixed episodes, which is having depressive and manic symptoms at the same time.

The manic episodes that occur in DB are characterized by the presence of an elevated and expansive mood for at least one week, which can lead the patient to be irritable. It is also accompanied by other symptoms such as excessive activity or decreased need for sleep and profoundly interferes with the person’s daily functioning.

For psychology professor Amparo Belloch, hypomanic episodes are similar to manic episodes, but hypomania does not interfere with the person’s daily life.

Mood stabilizing drugs

People going through psychological problems experience emotional turmoil from time to time, and this is normal. However, people with bipolar disorder need treatment to help prevent mania—that is, to stabilize the manic pole.

In this article, we will discuss two groups of commonly used stabilizing agents: lithium and anticonvulsants.

1. Lithium salts

For some authors, it is the cornerstone of pharmacological treatment in DB. Lithium is the classic mood stabilizer, so called because it has been used for more than 50 years in the treatment of bipolar disorder. It is an ion whose mechanism of action is still unknown but whose efficacy in manic episodes and relapse prevention has been proven and documented.

It is a mood stabilizer due to its anti-manic effect. Indeed, it is the first-line treatment for all phases of DB, especially for those patients in whom manic episodes predominate.

Although its mechanisms of action are not fully known, it is believed that it can increase serotonin and norepinephrine levels (thereby producing an antidepressant effect), while regulating dopamine levels (producing the antimanic effect).

Lithium requires close medical surveillance because its concentration in the blood must be between 0.6 and 1 mmol/l and its levels are relatively likely to be altered by everyday factors such as the amount of salt in the diet.

Its adverse effects are broad and include gastrointestinal symptoms such as dyspepsia, nausea, vomiting and diarrhea as well as weight gain, hair loss, acne, tremors or sedation.

2. Anticonvulsants

There are some medications used in the treatment of epilepsy that can be helpful in treating bipolar disorder. Although their mechanism of action is also unknown, it is thought that they may modulate the action of the neurotransmitter GABA, which is associated with calmness and relaxation. Some of the most commonly used anticonvulsants are:

• Valproic acid. Along with lithium, it is one of the most commonly used mood stabilizers. Its use in pregnant women should be avoided because it can cause malformations in the fetus, as well as in women of childbearing age. Treatment with this drug must also be carefully monitored because its blood levels must remain between 50 and 100 mg/L. The efficacy of valproic acid on the manic phase of BD has been demonstrated and is also effective in the treatment of migraine.
• carbamazepine. It was the first anticonvulsant to demonstrate its efficacy in the manic phase of BD. Its side effects include skin rashes and changes in sodium levels (hyponatremia). You also need adequate medical supervision because your blood levels must remain between 5 and 12 µg/ml. Its effects on the fetus are known, so it should be avoided in pregnant women and women of childbearing age. This drug is also useful in the treatment of neuropathic pain.
• Oxcarbamazepina. It is similar to the previous one, with the advantage that it is not necessary to check the concentration levels in the blood and has fewer side effects.
• Lamotrigine. It is a drug that has a solid track record of scientific evidence when it comes to preventing depressive and manic episodes in BD. It is one of the few psychoactive drugs that works on bipolar depression. Furthermore, it is generally well tolerated by patients.

Conclusions on mood stabilizing drugs

Currently there are many tools available that allow you to intervene in bipolar disorder and prevent recurrences.

The incidence tells us of repeated relapses after passing a phase of full recovery. Notwithstanding the above, much more research needs to be done and health policies implemented that combat the stigma associated with bipolar disorder and enable the full integration of these people as an essential and important part of our society.

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