Can crack cocaine addicts develop tolerance? Do they experience withdrawal symptoms?


Yes and yes. 

When crack cocaine is taken over a long period of time (chronic use), it can lead to the development of tolerance, where the effects from the first administration of crack cocaine are not produced by a second administration in a given period of time, unless a higher dosage is used. 'Nothing compares to the first hit', as addicts commonly put it. Some addicts continue to take higher doses of crack cocaine in order to intensify and prolong the 'good euphoric feeling' that it brings. 

After the initial 'high' feeling experienced from taking in crack cocaine, chronic users tend to experience withdrawal symptoms, also known as a 'crash'. This period consists of intense craving, depression and exhaustion (emotional withdrawal symptoms as opposed to physical withdrawal symptoms). Sadly,  there becomes a point where chronic users need to take in crack cocaine to feel normal, everyday pleasure.