Context: Studies conducted on both animals and humans show major bidirectional relationships between the circadian system and abusive drugs. It is indicated that these abusive drugs affect the central circadian pacemaker. Individuals suffering from substance abuse display disrupted rhythms. These disrupted rhythms can increase the risk for substance abuse and relapse. It is possible that genetic and/or environmental disturbances to the normal sleep and wake cycle can increase the susceptibility to addiction.

Question: What do studies show has a bidirectional relationship with the circadian system?
Answer: abusive drugs

Question: What do abusive drugs effect in the circadian system?
Answer: circadian pacemaker

Question: What do drug abusers show in their circadian processes?
Answer: disrupted rhythms

Question: What can the disrupted circadian system cause?
Answer: abuse and relapse

Question: What can disruption to genetics and environment in the sleep cycle cause?
Answer: susceptibility to addiction

Question: What studies show a minor relationship between the circadian system and drug abuse?
Answer: Unanswerable

Question: What is displayed by individuals when not abusing drugs?
Answer: Unanswerable

Question: What do steady rhythms increase?
Answer: Unanswerable

Question: What may be increased by a person's normal sleep and wake cycle?
Answer: Unanswerable