The finding that young Irish people are the biggest abusers of amphetamines and ecstasy in Europe is a cause for concern.
Amphetamine (speed) is an adrenaline-like chemical first synthesised in 1927. The original commercial preparation, Benzedrine, was marketed in 1932 in the form of a decongestant inhaler for people with asthma and hayfever.
Doctors soon became concerned after regular users described feeling depressed and irritable. Impulsive and aggressive behaviour were other features found in those who were able to buy the preparation over the counter.
Its use was restricted to prescription only from 1939 onwards. A derivative, dexamphetamine, is twice as strong as amphetamine.
In 1958, the phenomenon of amphetamine psychosis was first reported. Men in particular were found to be susceptible to a schizophrenia-like illness.
Popular among writers and artists, the author William Burroughs described its effects: "Large doses cause prolonged sleeplessness with feelings of exhilaration. The period of euphoria is followed by a horrible depression. The drug tends to increase anxiety. It causes indigestion and loss of appetite."
Hitler's personal physician included amphetamine in the regular "vitamin" injections he gave the Führer. John F. Kennedy supposedly used amphetamine during stressful summits with the Soviet leader Khrushchev.
Ecstasy became a popular drug of abuse in the 1990s. Its proper name is methylene-dioxymethamphetamine or MDMA. The drug was first produced in 1912 but found no medical use until psychiatrists began to use it in the 1970s.
Now it is primarily used by young people at all-night parties to help them remain physically and mentally active. People who have taken ecstasy describe feelings of euphoria, reduced fear and anxiety and reduced aggression. It also increases sexual appetite.
Repeat users of MDMA are prone to depression, panic attacks, hallucinations and psychosis.
Animal studies looking at the chronic use of ecstasy suggest it progressively destroys certain nerve cells in the brain. In humans this is likely to result in serious disturbance of thought patterns, confusion and changes in sensory perception.