Molecular Imaging of Addictive Behavior in Idiopathic Parkinson's Disease.

Parkinson's disease (PD) is commonly associated with motor symptoms, however cognitive and neurobehavioral complications are increasingly recognized and contribute to long-term disability. Dopamine replacement therapy is effective for motor symptoms, but can also lead to motor side-effects and addictive behavior such as impulse control disorders. Molecular imaging is advancing our knowledge of the mechanisms involved in the development of behavioral addictions. This chapter will discuss potential risk factors and associations with the development of addictive behavior in PD including the role of dopaminergic medication and genetic predisposition. We further will describe the common neurobiology and similarities of addictive behavior in PD to addiction, particularly the neuroanatomy of reward processing and its alteration in substance and behavioral addictions. Finally, we will discuss molecular imaging approaches which are helping to delineate the structure as well as the dynamic interactions between different components involving neurotransmitters, transporters, and receptors.