Psychiatry
Bipolar and Mood Disorders
Bipolar disorder for MBBS and NEET-PG: mania and hypomania, bipolar I versus II, lithium monitoring and toxicity, valproate and treatment of acute mania, mapped to NMC codes PS7.
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Bipolar and Mood Disorders
Bipolar disorder for MBBS and NEET-PG: mania and hypomania, bipolar I versus II, lithium monitoring and toxicity, valproate and treatment of acute mania, mapped to NMC codes PS7.
This chapter covers bipolar and related mood disorders. It explains the features of mania and hypomania, the distinction between bipolar I and II, and the mood stabilisers, with a strong focus on lithium, its monitoring and its toxicity, alongside the treatment of acute mania and long-term prophylaxis.
High-yield: Bipolar and Mood Disorders
- Bipolar disorder is characterised by episodes of mania or hypomania alternating with episodes of depression.
- A manic episode features elevated or irritable mood, increased energy, reduced need for sleep, grandiosity, pressured speech and flight of ideas lasting at least a week.
- Bipolar I requires at least one manic episode, while bipolar II involves hypomania with depressive episodes but no full mania.
- Hypomania is a milder, shorter elevation of mood without psychotic features or marked functional impairment.
- Psychotic features in severe mania are typically mood-congruent grandiose delusions.
- Lithium is the classic mood stabiliser, effective in acute mania and, importantly, in preventing relapse and reducing suicide.
- Lithium has a narrow therapeutic index and needs monitoring of serum levels, renal and thyroid function.
- Early lithium toxicity causes coarse tremor, vomiting, diarrhoea, ataxia and slurred speech, progressing to seizures and coma.
- Dehydration, non-steroidal anti-inflammatory drugs, thiazide diuretics and ACE inhibitors raise lithium levels and risk toxicity.
- Sodium valproate and carbamazepine are alternative mood stabilisers, and valproate is avoided in women of childbearing potential because it is teratogenic.
- Acute mania is treated with an antipsychotic, a mood stabiliser, or both, and antidepressants are used cautiously as they can trigger a switch to mania.
- Rapid cycling means four or more mood episodes in a year and predicts a poorer response to treatment.
- Cyclothymia is a chronic pattern of milder mood swings that do not reach full episodes.
- Long-term prophylaxis with a mood stabiliser and family education reduces relapse in this recurrent illness.
Mood stabilisers at a glance
- **Lithium:** First-line; prevents relapse and reduces suicide. Narrow therapeutic index, monitor levels.
- **Lithium toxicity:** Coarse tremor, vomiting, ataxia, slurred speech, seizures. Precipitated by dehydration and NSAIDs.
- **Valproate, carbamazepine:** Alternatives; valproate is teratogenic and avoided in women of childbearing potential.
- **Acute mania:** Antipsychotic and/or mood stabiliser; use antidepressants cautiously.
NMC competencies in this chapter
- **PS7.1:** Clinical features of bipolar disorders
- **PS7.2:** Indications and interpretation of investigations in bipolar disorder
- **PS7.3:** Treatment of bipolar disorders including behavioural methods
- **PS7.4:** Family education in bipolar disorder
- **PS7.5:** Pharmacological basis and side effects of mood stabilisers
- **PS7.6:** Conditions for specialist referral in bipolar disorder
- **PS7.7:** Long-term prophylaxis and relapse prevention
Frequently Asked Questions
What is the difference between bipolar I and bipolar II?
Bipolar I requires at least one full manic episode, while bipolar II involves hypomania together with depressive episodes but never a full manic episode.
Why does lithium need monitoring?
Lithium has a narrow therapeutic index, so serum levels are monitored to stay effective without becoming toxic, along with renal and thyroid function which lithium can affect.
What precipitates lithium toxicity?
Dehydration, non-steroidal anti-inflammatory drugs, thiazide diuretics and ACE inhibitors raise lithium levels, causing tremor, vomiting, ataxia and, in severe cases, seizures and coma.
Why are antidepressants used cautiously in bipolar disorder?
Antidepressants can trigger a switch from depression into mania or induce rapid cycling, so they are used carefully and usually alongside a mood stabiliser.
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