Synthesis, radioligand binding and molecular modeling studies of several 9-aminomethyl-9, 10-dihydroanthracene (AMDA) analogs were carried out to determine the extent of the steric tolerance associated with expansion of the tricyclic ring system and amine substitution at 5- HT2A and H1 receptors. A mixture of (7, 12-dihydrotetraphene-12-yl) methanamine and (6, 11-dihydrotetracene-11-yl) methanamine in a 75–25% ratio was found to have an ...