Is it possible for one to become addicted to sedating medications? products with ingredients such as diphenydramine, doxylamine, chlorphenirmine, etc?

No : Antihistamines are not addictive. They should be taken regularly for best results. Non sedating antihistamines have less side effects.

Yes for example: Diphenhydramine can have a paradoxical effect, over a long period of use / that is it can produce restlessness & agitation and anxiousness instead of drowsiness or sleep. Remember addiction/dependency starts as habitual use and abuse before it becomes a chemical dependency!