If you have just been prescribed a mood stabiliser, you have probably been handed a leaflet with a long list of possible effects and very little sense of which ones matter.
This explains what these medicines do, what monitoring they need, and — the part worth reading even if you skip the rest — the small number of symptoms that mean you should contact your doctor today rather than waiting.
This is general information. It does not replace your prescriber, and it deliberately contains no doses. Never change or stop a mood stabiliser on your own: with some of these, stopping abruptly carries its own risks.
What a mood stabiliser actually does
The name is slightly misleading. These medicines are not sedatives and they do not flatten your personality. Broadly, they reduce the height and depth of mood swings and lower the chance of further episodes — in bipolar disorder, that means fewer and less severe highs and lows, over years rather than days.
Two practical consequences follow. They work preventively, so the benefit is partly invisible: you are judging something that did not happen. And they take time — weeks for some effects, longer to know whether relapses are genuinely reduced. The National Institute of Mental Health describes them as a long-term part of treatment rather than a short course.
The main groups
Lithium
The oldest and still one of the most effective, particularly for preventing relapse. Its distinguishing feature is that the helpful level and the harmful level are not far apart, which is why regular blood tests are not optional. Levels are usually taken around 8 to 12 hours after the previous dose, and kidney and thyroid function are monitored as well.
Two practical points people are often not told clearly:
- Anti-inflammatory painkillers (NSAIDs) such as ibuprofen can raise lithium levels. Check with your doctor or pharmacist before taking them; paracetamol is often preferred.
- Dehydration raises levels too. That matters in a Delhi NCR summer, during stomach upsets, and if you are unwell with fever. Keep fluids up and tell your doctor if you have had vomiting or diarrhoea.
Valproate (sodium valproate, valproic acid)
Effective, widely used, and carrying one critical restriction described below. Monitoring focuses on liver function and blood counts. Unexplained bruising or bleeding, or severe abdominal pain with vomiting, should be reported promptly.
Lamotrigine
Used particularly where depressive episodes dominate. Its key issue is rash — see the safety section below, because this one genuinely matters.
Carbamazepine
Also used as a mood stabiliser. Monitoring covers liver and kidney function, and rash.
Relevant for patients in India: carbamazepine carries a risk of serious skin reactions linked to a genetic variant, HLA-B*1502, which is more common in people of Asian descent. Genetic screening before starting is recommended for patients of Asian ancestry. If you are offered carbamazepine and this has not been discussed, ask about it.
Some antipsychotics
Several medicines usually described as antipsychotics are also used to stabilise mood, alone or alongside the above. Their main practical issue is often metabolic — see weight gain from psychiatric medication.
Call your doctor the same day if
Most side effects are nuisances that settle. These are the exceptions.
Any rash while taking lamotrigine — particularly in the first eight weeks, and especially with fever, blistering, mouth or eye involvement, or if you feel unwell with it. Lamotrigine carries a boxed warning for severe skin reactions including Stevens-Johnson syndrome. The standard advice is to stop and seek review at the first sign of rash unless it is clearly unrelated. Do not wait to see if it fades.
Signs of lithium toxicity — coarse tremor, vomiting or diarrhoea, unsteadiness, slurred speech, marked drowsiness or confusion. This is a medical emergency, not a side effect to mention next month.
On valproate or carbamazepine: yellowing of the eyes or skin, unexplained bruising or bleeding, persistent vomiting with severe abdominal pain, or a widespread rash.
Any new or worsening thoughts of self-harm, on any of these.
Valproate and pregnancy
This deserves its own section because it is the most consequential thing on this page.
Valproate taken during pregnancy is associated with a substantially increased risk of birth defects and of effects on a child's development. The risk is dose-related and no safe threshold has been established. It is often described as having a near-absolute contraindication in pregnancy — stronger than any other common psychiatric medication.
What this means practically:
- If you are a woman of childbearing age and valproate is being considered, that conversation should include alternatives and reliable contraception.
- If you are taking valproate and planning a pregnancy, raise it before conceiving, not after.
- If you take valproate and discover you are pregnant, contact your doctor straight away — and do not stop abruptly on your own, because uncontrolled illness in pregnancy carries its own serious risks. This needs managing, not improvising.
Lithium and carbamazepine also carry pregnancy-related risks and require specialist discussion. The general point holds for all of them: plan the conversation early.
The side effects people actually stop over
Serious reactions are rare. The common reasons people quietly abandon mood stabilisers are more ordinary — and most are manageable if raised.
- Weight gain and appetite change, especially with valproate and some antipsychotics
- Fine hand tremor, common with lithium
- Feeling mentally slowed or "flat" — this is worth reporting rather than enduring; it is often adjustable
- Thirst and passing more urine, with lithium
- Nausea and drowsiness, often worst early and improving
- Hair thinning, with valproate
Stopping without telling anyone is the most common and most costly response. Relapse after abrupt discontinuation is a well-recognised problem, and your prescriber usually has options — a different drug, a different schedule, a different dose.
Living with the monitoring
Blood tests are the part people find most irritating, and the part most worth understanding, because the reason differs between drugs.
For some mood stabilisers the amount in your blood has to sit within a fairly narrow range — too little and it does not work, too much and it becomes harmful. Testing is how that is kept right, and it is also why the timing of the sample relative to your last dose matters. Ask when to attend; a sample taken at the wrong point gives a misleading result and may prompt an unnecessary change.
Other tests are checking that organs handling the drug are coping, and are typically more frequent at the start and when a dose changes, then settled into a routine interval.
Two practical points. Keep your own copy of each result, because continuity of care in India frequently depends on the patient holding the records. And if you miss a scheduled test, say so rather than letting an appointment proceed on old numbers.
Other medicines, and what to tell a new doctor
Mood stabilisers interact with a good many common drugs, including some painkillers, some antibiotics, and other psychiatric medicines. Dehydration and significant changes in salt intake can also matter for some of them, which is worth knowing in an Indian summer or during an illness with vomiting or diarrhoea.
So: tell any doctor you see — including a dentist, a gynaecologist or a casualty officer who has never met you — exactly what you take. Carry a photograph of the packet on your phone. And check before starting anything bought over the counter, including supplements, which are not inert simply because they are sold without a prescription.
Frequently asked questions
How long will I need to take this?
Often long-term, because the purpose is preventing future episodes rather than treating a current one. That is a discussion to revisit with your psychiatrist periodically, not a life sentence imposed at the first appointment.
Can I drink alcohol on a mood stabiliser?
Ask your prescriber about your specific medication. In general alcohol worsens mood instability and sleep, and interacts with several of these drugs.
Why do I need so many blood tests?
Mainly for lithium, where the effective and toxic levels are close together, and for valproate and carbamazepine, where liver and blood counts are monitored. The tests are how these medicines are used safely.
Will it change who I am?
It should not. If you feel dulled or disconnected, that is a side effect to report, not something to accept — it is one of the more common and more adjustable complaints.
Can I stop once I feel well?
Feeling well is usually evidence the medicine is working rather than that it is no longer needed. Stopping is sometimes appropriate, but it should be planned with your doctor and tapered, not abrupt.
If you are weighing this up
The decision about a mood stabiliser is genuinely a shared one, and it should involve a frank discussion of what it is preventing, what it will cost you in side effects and monitoring, and what the alternatives are.
SSHIMOH's clinical team treats bipolar disorder on an outpatient and inpatient basis, and a consultation is the right place to ask the questions this article cannot answer for your particular case.