Typical antipsychotics are D2 receptor antagonists that inhibit all three dopamine pathways, treating positive symptoms but causing severe side effects by blocking motor and lactation pathways. Atypical antipsychotics are milder D2 antagonists that also act on serotonin, glutamate, and other neurotransmitters. They reduce positive symptoms through D2 antagonism in the mesolimbic pathway and 5-HT2A antagonism, which decreases dopamine output. Their additional actions help avoid inhibiting the nigrostriatal pathway, reducing motor side effects.