Several studies have reported on structural abnormalities, decreased myelination and oligodendrocyte dysfunction in post-mortem brains from schizophrenic patients. Glia-derived cholesterol is essential for both myelination and synaptogenesis in the CNS. Lipogenesis and myelin synthesis are thus interesting etiological candidate targets in schizophrenia. Using a microarray approach, we here demonstrate that the antipsychotic drugs clozapine and haloperidol upregulate several genes involved in cholesterol and fatty acid biosynthesis in cultured human glioma cells, including HMGCR (3-hydroxy-3-methylglutaryl-coenzyme A reductase), HMGCS1 (3-hydroxy-3-methylglutaryl-coenzyme A synthase-1), FASN (fatty acid synthase) and SCD (stearoyl-CoA desaturase). The changes in gene expression were followed by enhanced HMGCR-enzyme activity and elevated cellular levels of cholesterol and triglycerides. The upregulated genes are all known to be controlled by the sterol regulatory element-binding protein (SREBP) transcription factors. We show that clozapine and haloperidol both activate the SREBP system. The antipsychotic-induced SREBP-mediated increase in glial cell lipogenesis could represent a novel mechanism of action, and may also be relevant for the metabolic side effects of antipsychotics. 2 Heritability has been demonstrated to play an important role in the etiology, but numerous genetic linkage and association studies have yielded conflicting results, although there are now several promising candidate susceptibility genes. 3 Brain imaging studies of schizophrenic patients have shown various structural and functional abnormalities, including enlargement of the ventricles and volume reductions in specific brain regions, 4,5 even in first episode and drug-naïve subjects. [6][7][8] On the other hand, degenerative histopathological findings are strikingly absent. These observations hint at a neurodevelopmental origin of the disorder (for a review, see Harrison and Lewis 9 and Liddle and Pantelis 10 ).