MAINTENANCE PHASE/PROPHYLACTIC TREATMENT (see algorithm)

If the patient has remained stable through the continuation phase of treatment, the clinican, patient and family need to consider the value of prophylactic mood stabilizer treatment, which can reduce morbidity and mortality risks and improve the quality of life. The decision is relatively easier in patients who have had recurrent episodes, where the illness is very severe, or where there is a strong family history of bipolar disorder. Unfortunately the vast majority of patients have recurrent episodes. It is difficult, if not impossible, to accurately predict the very small minority of patients diagnosed with bipolar disorder who will never have a further episode of mood disorder during their lifetime. Hence, the recommendation for prophylactic treatment should be the rule. There should be very good reason not to recommend robust prophylactic treatment in a patient with a well diagnosed bipolar disorder. Apart from the rare patient who cannot tolerate any treatment, the other situation where the decision to recommend indefiniate prophylaxis may be deferred is in patients with a single episode of hypomania with no history of depression and no family history of bipolar disoder. However, even with these patients every effort should be made to ensure mood stabilizer treatment for about a year. When medication is being discontinued this should be done on a gradual basis over about 3 months, but not less than 1 month. Patients who discontinue treatment should have access to regular monitoring, rapid reassessment and treatment if required.

Lithium is the medication with proven prophylactic efficacy in bipolar disorder. It has been used in large numbers of patients, tested in double-blind conditions, and used over many years. It has proven efficacy in classical, non-rapid cycling, non-mixed states, primary bipolar disorder at serum levels of 0.8-1.1 mmols/l. There is an increased risk of relapse at serum levels below 0.8 mmols/l, particularly below 0.6 mmols/l. There is growing evidence from several open studies that Divalproex has significant prophylactic efficacy similar to Lithium. At two recent conferences, the results of a double blind multicentre study comparing Lithium, Divalproex and placebo in the prophylaxis of bipolar disorder showed that Divalproex and Lithium had equal efficacy and were superior to placebo in patients with moderate to severe illness. This study is as yet unpublished. Divalproex may also be useful in early onset bipolar disorder and in secondary bipolar disorder. There is some good evidence that Carbamazepine has prophylactic efficacy, but, more recently, its efficacy has come into question in long term use and in rapid cycling conditions. It too, like Divalproex, is useful in secondary bipolar disorder.

Few patients manage a lifetime of bipolar disorder with monotherapy. Most patients require short or long term polytherapy with mood stabilizers and or ECT. A very small sub-group of patients may be totally refractory to mood stabilizers and may require an atypical neuroleptic, like Clozapine, or maintenance ECT.

Serum levels of medication and other monitoring/investigations of bodily systems should be conducted as clinically indicated, but no less than once every 6 months.