Rank order of antipsychotics for producing weight gain

A review in the Archives of General Psychiatry looks at the evidence for weight gain and changes in other cardiovascular risk factors caused by antipsychotic treatment. It has produced a rank order of the different drugs with olanzapine noted to cause more weight gain than all other second-generation antipsychotics except clozapine. Clozapine causes more weight gain than risperidone, risperidone more than amisulpride, and sertindole more than risperidone. The average weight gain after 6 to 8 weeks taking olanzapine was found to be 5 to 6 kg, which was significantly higher than the average weight gained while taking risperidone (4 kg) or haloperidol (3 kg).

Antipsychotic medication does seem to reduce brain volume

I have mentioned a study in a previous blog entry that seemed to show that antipsychotic medication reduces brain volume. This study was referred to in an interview with Nancy Andreasen. The point I was making in the previous entry was that the research had been "sat on" for fear it may lead to people stopping their medication.

The study has now been published in the Archives of General Psychiatry. The authors mention, as I did in my previous blog entry, that an association does not necessarily mean a causal connection. However, the evidence is quite strong considering that illness severity and substance misuse had minimal or no effects and data from animal studies also suggests brain tissue loss.

Of course we have known for some time from clinical evidence that antipsychotics cause brain damage in that tardive dyskinesia is not necessarily reversible when antipsychotic medication is discontinued. This is reflected in the finding of a specific increase in size in the putamen in the present study. We don't know that brain changes are necessarily "bad" for patients, but, as the study itself concludes, we have to entertain the possibility that antipsychotics may have potentially undesirable effects of brain tissue volume reduction.