What are anticonvulsants? 

Anticonvulsant medications influence the actions of neurotransmitters including glutamate and GABA, leading to a decrease in brain cell (neuron) excitability. They may be prescribed as an immediate adjunct to antipsychotic medication in order to treat acute symptoms of psychosis, such as aggressive behaviour. They may also be used as part of an ongoing treatment regime in order to supplement antipsychotic effects or combat side effects like movement disorders. Anticonvulsant medications assessed in this topic primarily include valproate, carbamazepine, and lamotrigine.

What is the evidence for adjunctive anticonvulsants?

Moderate to low quality evidence suggests a medium-sized effect of  improved mental health with adjunctive lamotrigine as measured on some but not all assessment scales, and with adjunctive valproate, particularly in the short-term (< 4 weeks). Lamotrigine is associated with an increased risk of any adverse effect compared to placebo.

There may be some benefit of adjunctive valproate for reducing aggressive behaviour in the short term (1 week), but not in the longer term (4 weeks). There is a lower risk of constipation and tardive dyskinesia with valproate, but an increased risk of sedation compared to placebo.

Moderate to low quality evidence suggests no improvements in symptoms after augmenting clozapine with lamotrigine or topiramate in treatment-resistant patients.

September 2020

Last updated at: 5:11 am, 21st September 2020
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Title Colour Legend:
Green - Topic summary is available.
Orange - Topic summary is being compiled.
Red - Topic summary has no current systematic review available.