Impulse Control Disorders: Disorders whose essential features are the failure to resist an impulse, drive, or temptation to perform an act that is harmful to the individual or to others. Individuals experience an increased sense of tension prior to the act and pleasure, gratification or release of tension at the time of committing the act.Gambling: An activity distinguished primarily by an element of risk in trying to obtain a desired goal, e.g., playing a game of chance for money.Impulsive Behavior: An act performed without delay, reflection, voluntary direction or obvious control in response to a stimulus.Trichotillomania: Compulsion to pull out one's hair.Parkinson Disease: A progressive, degenerative neurologic disease characterized by a TREMOR that is maximal at rest, retropulsion (i.e. a tendency to fall backwards), rigidity, stooped posture, slowness of voluntary movements, and a masklike facial expression. Pathologic features include loss of melanin containing neurons in the substantia nigra and other pigmented nuclei of the brainstem. LEWY BODIES are present in the substantia nigra and locus coeruleus but may also be found in a related condition (LEWY BODY DISEASE, DIFFUSE) characterized by dementia in combination with varying degrees of parkinsonism. (Adams et al., Principles of Neurology, 6th ed, p1059, pp1067-75)Dopamine Agonists: Drugs that bind to and activate dopamine receptors.Benzothiazoles: Compounds with a benzene ring fused to a thiazole ring.Tropanes: N-methyl-8-azabicyclo[3.2.1]octanes best known for the ones found in PLANTS.Antiparkinson Agents: Agents used in the treatment of Parkinson's disease. The most commonly used drugs act on the dopaminergic system in the striatum and basal ganglia or are centrally acting muscarinic antagonists.Reward: An object or a situation that can serve to reinforce a response, to satisfy a motive, or to afford pleasure.