Biological basis of anxiety and strategies for pharmacological innovation

Very little is known about the biological basis of anxiety disorder. Variance in personality traits, including those related to anxiety, is thought to be generated by a complex interaction of environmental and experiential factors with a number of gene products involving distinct brain systems such as the midbrain raphe serotonin (5-hydroxytryptamine, 5-HT) system (Loehlin, 1989; Plomin et al., 1994). Although twin studies have indicated that individual variation in measures of anxiety-related personality traits is 40-60% heritable, none of the relevant genes has yet been identified (Loehlin, 1989).