Lamotrigine is an established anticonvulsant agent and also an effective maintenance therapy for bipolar disorder. In Italy it is approved for the treatment of epilepsy with partial seizures, partial seizures with secondary generalization and generalized seizures, both in monotherapy and as an add-on therapy in patients with refractory epilepsy; it is also approved for the prevention of depressive episodes in patients with bipolar disorder with a predominant depressive component. Lamotrigine is generally well tolerated; however, some psychiatric problems have been reported in patients using the drug to treat mental disorders (mainly bipolar) or epilepsy. The clinical features of these psychiatric side effects are: affective switches, full acute psychotic episodes, and hallucinations. In conclusion, lamotrigine is an effective drug, very useful in the therapy of epilepsy and mood disorders, but clinicians have to be aware of the risk that it can induce psychiatric symptoms or acute episodes.