Schizophrenia is a major mental disorder affecting about 1% of the general population. The symptoms of the disorder significantly affect the social, occupational and interpersonal functioning of the affected person. In spite of promising treatments for schizophrenia over the last fifty years, at least one-fifth to one-third of affected people fail to respond to treatment. In such cases, additional drugs may be administered to improve treatment response. One such drug is lamotrigine, which was introduced primarily for epilepsy ('fits'). So far there has not been any systematic analysis of those reports that have suggested the benefit of lamotrigine for people with schizophrenia, hence we undertook this review.
We searched major medical databases for studies that have examined the use of lamotrigine for people with schizophrenia. We identified five relevant studies that were conducted according to existing standards of research. A total of 537 people with schizophrenia participated in these five studies. The participants were resistant to various degrees to usual treatments and were randomised to receive either lamotrigine or placebo in addition to their usual drugs. The data regarding effectiveness could only be usefully analysed in less than 70 participants. Lamotrigine was considered to be effective if the questionnaire scores showed a greater reduction than for those who received placebo. The magnitude of this effect was small when compared to placebo.
Data regarding adverse effects were available from three studies. There was a higher occurrence of nausea in those receiving lamotrigine. Apart from this the common side effects were headache and dizziness.
The current evidence does not suggest that the addition of lamotrigine is a remarkable strategy for people with resistant schizophrenia, but the results are suggestive of a positive effect on the symptoms of schizophrenia. However, more studies with larger number of participants are needed to confirm the true magnitude of benefit and safety. This review is limited by the poor presentation of data from the individual studies.
Premkumar, T.S.; Pick, J. Lamotrigine for schizophrenia. Cochrane Database of Systematic Reviews (2006) (Issue 4) Art. No.: CD005962. [DOI: 10.1002/14651858.CD005962.pub2]