Contrary to popular belief, the 'typical' overdose victim is not a young novice or inexperienced user. Rather, the average age of death reported is in the late twenties and early thirties. Eighty per cent of deaths were classified as dependent, regular users. Given that the mean age of death reported in most studies is approximately 30 years, and that heroin-using careers typically start in the late teens, most fatal cases have been using heroin for a considerable amount of time prior to death. They do not, on the whole, appear to be novice users but older dependent heroin users. Deaths do occur among recreational heroin users as well. It is estimated that 17% of heroin overdose deaths are by recreational/weekend users.

The psychological effects of methamphetamine include, euphoria, dysphoria, increased attention, increased alertness, excessive talking, rapid speech, irritability, nervousness, anxiety, paranoia, delusions of grandeur, panic, aggressive and sometimes violent behavior, severe depression, suicidal tendencies, hyperactivity and excitability, increased sense of well-being, and emotional lability. Occasionally excessive and/or chronic use of methamphetamine can lead to amphetamine psychosis, with side effects such as hallucinations, paranoia, delusions, and thought disorder.

In the US, opium was used to treat soldiers during the Civil War (1861-1865). During the late 1800s, doctors prescribed "tonics" containing opiates for many conditions. Rarely did these medicines list opiates as one of the ingredients. In fact, heroin was marketed as a cough medicine and a cure for morphine addiction. However, many physicians had concerns about possible addiction to these medicines.

From 1898 through to 1910 heroin was marketed as a non-addictive morphine substitute and cough suppressant. Bayer marketed heroin as a cure for morphine addiction before it was discovered that heroin is rapidly metabolized into morphine, and as such, "heroin" was basically only a quicker acting form of morphine. The company was somewhat embarrassed by this new finding and it became a historical blunder for Bayer.