1-phenyl-3,4-dihydroisochinoline (3,4-Dihydro-1-phenylisoquinoline) is a structural analog of the neurotransmitter dopamine that interacts with dopamine receptors in the central nervous system. It has been studied as a potential therapeutic agent for the treatment of neurological disorders such as Parkinson's disease, Alzheimer's disease and Huntington's chorea.