Drosophila strategies to study psychiatric disorders.

For decades, Drosophila melanogaster has been used as a model organism to study human diseases, ranging from heart disease to cancer to neurological disorders [9]. For studying neurodegenerative diseases, Drosophila has been instrumental in understanding disease mechanisms and pathways as well as being an efficient tool in drug discovery studies. For some better-understood disorders, such as Fragile X (a mental retardation syndrome), clinical trials are being run, based in part on translational work in flies and rodents. However, Drosophila is currently less used to study psychiatric disorders such as autism, schizophrenia and attention deficit and hyperactivity disorder (ADHD), despite numerous discoveries of disease susceptibility genes that could be explored by reverse genetics or miss-expression studies. This deficit might be explained by (1) a lack of reliable tests to study more complex disease (endo)phenotypes in flies, (2) difficulties in translating disease symptoms into animal models and (3) the polygenetic nature of these diseases. In this review we discuss strategies to use D. melanogaster to study complex psychiatric disorders such as schizophrenia, autism and ADHD. Two common features of these diseases may be defective sleep and attention mechanisms, hence calling for better methods for quantifying and screening arousal thresholds in flies.