Risks of ADHD Medications - Part II
3. Increased risk of addiction (myth)
A common concern about ADHD stimulant medication is its potential for abuse. This is why stimulants are classified as Schedule II medications. These drugs are closely monitored in the United States. Stimulants increase wakefulness, suppress appetites, and increase focus and attention. These qualities make these drugs appealing to some people for weight loss or performance enhancement (e.g., studying all night, enhanced sports performance). In addition, some stimulant medications produce euphoria. This makes them appealing to recreational drug users. While these are sensible concerns, research suggests that there is no increased risk of substance abuse for people who have ADHD and take medication, versus those who do not take medication (Molina, 2012; www.drugabuse.gov).
Another concern is that people may feign ADHD symptoms in order to obtain stimulant prescriptions for illicit drug use, or sale. Adderall and Dexedrine are popular in the illicit drug trade because they produce a euphoric high in people who do not have ADHD. Ritalin does not produce the euphoria desired by illicit drug users so it has less potential for abuse.
According to a recent study, the number of children diagnosed with ADHD increased by 24 percent from 2001 to 2011 ( (Shute, 2013)Over this same period, the number of stimulant prescriptions for ADHD has soared. The more prescriptions that are written, the more pills become available for illicit purposes. Several recent surveys found that between 8 to 35 % of college students report that they have used stimulants to increase academic performance (Shute, 2013). Given the large number of ADHD stimulants being prescribed today, it is highly likely that some of these medications end up being sold on the street. This is a legitimate concern and it places physicians in a bind. Clearly, physicians do not want to contribute to the substance abuse problem of modern times. However, doctors are ethically obligated to treat people who seek their help. As we reviewed, these medications can make a huge difference for people who need them.
Tolerance and withdrawal symptoms are typically considered the harbingers of addiction. Tolerance refers to a decreasing drug effect over time. Tolerance causes the drug user to take increasingly higher doses to achieve the effect they desire. However, we do not typically see tolerance with ADHD. Once an effective ADHD medication regime has been established, people rarely need to increase their dose. In fact, some adults may find they respond well to lower doses of medication. Withdrawal refers to physiological or bodily dependence on medication. Once again, we do not usually see withdrawal with ADHD. In the absence of tolerance or withdrawal we may reasonably conclude that addiction has not occurred.
In summary, the research indicates that ADHD medications themselves do not lead to later addiction. Nonetheless, people with ADHD are at greater risk of drug addiction whether or not they are treated with stimulant medication. These findings suggest that ADHD treatment for youth should include interventions aimed at reducing the risk off future substance abuse. The cause of this increased risk is unclear. It could be that impulsivity is to blame, or perhaps it may be an attempt to self-medicate. Certain subgroups of ADHD children have an even greater risk for addiction. This at-risk group includes children who demonstrate delinquent behaviors (conduct disorders) by age 10, and those who smoke cigarettes by age 12 (Wilens, 2004). Clearly these two things do not cause addiction. Nonetheless, they serve as predicators that help to identify children who are especially at risk. Researchers recommended this high-risk subgroup of children be identified as early as possible. Once identified, their treatment plan can be tailored to limit drug abuse potential.
4. Stunted growth
ADHD medications can suppress a child's appetite. This in turn affects a child's physical growth and development. In 2007, a major study showed that after 3 years, children taking the ADHD medication, Ritalin®, were behind their peers in growth. On average, they were one inch shorter and 6 pounds lighter (DeNoon, 2007).
The National Institute of Mental Health (NIMH) has funded studies to explore this topic. One example of NIMH-funded research is the Preschoolers with ADHD Treatment Study (PATS). This study examined 300 preschoolers (ages 3 to 5 years old) who had been diagnosed with ADHD. The study found that low doses of the stimulant methylphenidate are safe and effective for preschoolers. However, the study also found that young children are more sensitive to the side effects of the medication, including slower growth rates DeNoon, 2007). In contrast, a recent long-term study examined children on ADHD medication for a period of 10 years. By the end of the 10-year study, the researchers found no differences in height or weight between these children and children who weren't on medications (What we Know About the Long-term Effects of ADHD Medication, n.d.). This study did find that differences were observed during the first two years of taking medication. However, over time, most children regained lost ground and caught up with other kids. The study also found no lag in growth in children who go off medication during the summer. This practice is believed to lessen potential consequences of medications, such as growth delay. More research is being conducted to confirm these findings. Children taking methylphenidate or other ADHD medications should be closely monitored (What we Know About the Long-term Effects of ADHD Medication, n.d.).
5. Long-term consequences of stimulant medication on a child's brain
ADHD stimulant medications cause changes to neurotransmitter levels in the brain. You may recall that neurotransmitters are essential to the brain's communication system. Some researchers believe these changes are caused by the brain's adaptation to the medication. It remains to be determined whether these brain changes are permanent, or if there are significant long-term consequences of these changes. Further research is needed to help to identify the consequences of long-term stimulant use in people with ADHD.
6. Increased suicide risk
Some antidepressants medications have been linked to increased suicidal thoughts and behavior, particularly in youth. Most concern involves a group of antidepressants commonly called SSRIs (selective serotonin reuptake inhibitors). According to results across 24 studies and 4600 children, 2-3% of these children will think about, or attempt, suicide (Antidepressant May Bring Suicidal Thoughts in Children, 2006). The first 4 weeks after a patient begins medication, or changes dosage, is the most vulnerable time period.
A more recent study found that children and young adults who start taking an antidepressant medication, at higher than typical dosages, are at increased risk of suicidal behavior during the first 3 months of treatment (McCain, 2009). Compared to those with typical doses, researchers believe that the rate of suicidal behavior is twice as high for the atypical group. The researchers also found that more than half of the patients who started medication at such a high dose were evaluated and diagnosed by a primary care physician (generalist). The authors suggest that caregivers should initially work with an ADHD specialist prescriber (e.g., a psychiatrist) to establish the proper medication and dosage. Regardless of who prescribes the medication, caregivers should carefully watch for signs of worsening depression or thoughts about suicide. Other symptoms of concern are anxiety, panic attacks, impulsivity, uncontrollable restlessness, mania, agitation, insomnia, irritability, hostility, impulsivity, and mania. Promptly report these symptoms or any other unusual behavior to the healthcare provider.
7. Cardiovascular problems
People with active heart disease and high blood pressure should avoid stimulant medication. It may exacerbate heart or circulatory symptoms. One study in Denmark, included more than 700,000 children. It found 8,300 had ADHD (Tumolo, 2014). Within this ADHD group, those taking stimulants for ADHD were at twice the risk of experiencing a cardiovascular event compared to children who were not. Experts believe that the results of this large, well-conducted study confirm anecdotal reports of increased cardiac risk for children taking stimulant medications. Treatment guidelines recommend an assessment of cardiac risk before beginning stimulant treatment. Guidelines also recommend that cardiac risk assessments continue periodically throughout treatment.