In which disorders has dopamine dysfunction been primarily implicated?

Dopamine dysfunction has been primarily implicated in Parkinson's disease because this neurological disorder is characterized by the degeneration of dopamine-producing neurons in the substantia nigra, a critical area of the brain that affects movement and coordination. The lack of dopamine leads to the hallmark symptoms of Parkinson's, such as tremors, rigidity, and bradykinesia (slowness of movement).

In contrast, while dopamine also plays a role in mood regulation and various mental health conditions, it is not as central to the primary pathology of anxiety disorders, personality disorders, or obsessive-compulsive disorder as it is in Parkinson's disease. For example, obsessive-compulsive disorder (OCD) has been linked to serotonin dysfunction more than to dopamine; the treatment often involves SSRIs (selective serotonin reuptake inhibitors) which target serotonin rather than dopamine pathways. Thus, among the listed disorders, Parkinson's disease stands out as the condition in which dopamine dysfunction is most directly and primarily implicated.