Chronic amphetamine abuse can lead to powerful psychological dependency. Chronic abuse can lead to psychosis, paranoia and aggressive behaviour. Paranoid delusions are common amongst heavy users, who often carry weapons. Use of amphetamines contributes to the violence of the yakuza scene. Amphetamines also cause serious physical health problems including damage to the liver, kidneys or stomach.
Users lose weight up to the point of severe malnutrition.
Since amphetamines interfere with the calcium supply of the body they can cause damage to bones and loss of teeth. In habituated users withdrawal of the drug leads to severe depression, which prompts them to use more of the drug to relieve the depression. While many users only use the drug casually at lengthy intervals, some users become so attracted to the drug that they lose control of use and don't stop until they have caused serious health, financial, legal and other problems. Since the drug is only available from criminals, some addicted users get drawn into other criminal activities, such as storage of drugs, smuggling or prostitution in return for drugs. Problems amplified by drug prohibition When a substance for which there is a significant demand is made unavailable in legal shops such as pharmacies, its supplies will shift to black market channels and prices will go up.