ADHD and substance abuse
Studies suggest that having attention deficit hyperactivity disorder (ADHD) increases a person's risk of substance abuse, such as alcohol or drugs.
Other research has suggested that increased levels of smoking, alcohol and illicit drug use in young people with ADHD may be because of an attempt to self-medicate to manage their symptoms.
Why are people with ADHD more likely to abuse drugs and alcohol?
People with ADHD tend to be more impulsive and likely to have behavioural problems, both of which can contribute to substance abuse, say researchers. Also, both ADHD and alcoholism tend to run in families. A child with ADHD who has an alcoholic parent is more likely to develop an alcohol-abuse problem. Researchers have pointed to common genes shared between ADHD and alcoholism.
Are stimulant medications for ADHD addictive?
Parents sometimes worry whether the stimulant drugs their children are taking to treat ADHD (such as methylphenidate) are themselves addictive. Stimulant medications work by raising levels of a chemical messenger called dopamine in the brain, which helps improve focus and attention - skills people with ADHD often find difficult to master.
Dopamine also affects emotion and the feeling of pleasure, creating a 'high' that makes people want more. Because cocaine and other street drugs also raise dopamine levels there has been concern that ADHD stimulants might be similarly addictive. Methylphenidate’s ability to increase energy and focus has even led some people to refer to it as the 'poor man's cocaine'.
There have been reports of people using ADHD stimulant drugs that weren’t prescribed for them. People have crushed and snorted methylphenidate tablets, or dissolved the drug in water and taken it intravenously. Studies show that abusing methylphenidate can lead to dependence on the drug. When taken as prescribed though, methylphenidate is not addictive in children or adults.
In large doses, methylphenidate does have effects similar to those of cocaine. However, researchers have found marked differences between the two drugs. One of the factors that leads to addiction and abuse is how quickly a drug raises dopamine levels. The faster dopamine levels go up, the greater the potential for abuse. One researcher found methylphenidate takes about an hour to raise dopamine levels in the brain, compared to only seconds with inhaled cocaine. The doses of methylphenidate and other stimulants used to treat ADHD tend to be lower and longer-acting, which reduces the risk of addiction.
Does using stimulants for ADHD lead to substance abuse problems?
Several studies have set out to investigate the possible link between ADHD stimulant medication and substance-abuse problems, and there doesn’t appear to be any connection.
One of the longest-term studies, which followed 100 boys with ADHD for 10 years, showed no greater risk of substance abuse in boys who took stimulant drugs compared to those who didn’t. An earlier study by the same authors even suggested that stimulant use might protect against later drug abuse and alcoholism by relieving the ADHD symptoms that often lead to substance abuse. The earlier the stimulants are started, the lower the potential for later substance abuse.
How are alcoholism and drug abuse treated in people with ADHD?
It is important to remember that not everyone with ADHD will develop an alcohol or substance-abuse problem. It is unclear whether methylphenidate and other stimulants are effective treatments for ADHD patients with substance-abuse problems. These drugs may be useful when prescribed in a long-acting form and in a controlled way, so patients do not become too dependent on them. Therapy can also be an important part of the substance-abuse programme for people with ADHD.