Final answer:
Dopamine is associated with feelings of pleasure, motivation, and movement, and its balance is crucial for cognitive processing. Both deficits and excesses of dopamine are linked to various psychiatric conditions and behaviors, such as addiction, Parkinson's Disease, and ADHD.
Step-by-step explanation:
Dopamine (DA) is a neurotransmitter that plays a crucial role in our brain's reward system, influencing pleasure, addiction, movement, and motivation. When behaviors lead to dopamine release, they are likely to be repeated due to the feeling of pleasure it brings. A balanced DA transmission is essential for proper cognitive processing, particularly within the frontocortical level where it impacts decision-making, judgment capacity, planning, working-memory, attention, cognitive flexibility, and impulsivity.
Deficiencies or an excess of dopamine can lead to a range of adverse effects. For example, overactivity in the mesolimbic dopamine system can give rise to addictive behaviors or substance dependence, while deficits in dopamine can be a hallmark of Parkinson's Disease, leading to motor and cognitive impairments. Other psychiatric conditions, such as schizophrenia, mood disorders, and ADHD, also involve dopamine dysregulation, prompting treatments that target dopaminergic systems to improve cognitive functions.