Another review indicated that, based upon the longest follow-up studies conducted to date, lifetime stimulant therapy that begins during childhood is continuously effective for controlling ADHD symptoms and reduces the risk of developing a substance use disorder as an adult.Current models of ADHD suggest that it is associated with functional impairments in some of the brains neurotransmitter systems; these functional impairments involve impaired dopamine neurotransmission in the mesocorticolimbic projection and norepinephrine neurotransmission in the noradrenergic projections from the locus coeruleus to the prefrontal cortex. Psychostimulants like methylphenidate and amphetamine are effective in treating ADHD because they increase neurotransmitter activity in these systems. Approximately 80% of those who use these stimulants see improvements in ADHD symptoms. Children with ADHD who use stimulant medications generally have better relationships with peers and family members, perform better in school, are less distractible and impulsive, and have longer attention spans. The Cochrane reviews on the treatment of ADHD in children, adolescents, and adults with pharmaceutical amphetamines stated that short-term studies have demonstrated that these drugs decrease the severity of symptoms, but they have higher discontinuation rates than non-stimulant medications due to their adverse side effects. A Cochrane review on the treatment of ADHD in children with tic disorders such as Tourette syndrome indicated that stimulants in general do not make tics worse, but high doses of dextroamphetamine could exacerbate tics in some individuals.
Comorbid disorders make determining what symptoms are signs of bipolar disorder and which are due to other disorders (e.g., OCD, ADHD, disruptive behavior problems) difficult, leading to complications in treatment. For example, a common treatment for OCD are serotonin re-uptake inhibitors (SRIs), however, SRIs can lead to mood instability and worsening bipolar disorder. The most common misdiagnosis for ADHD in the USA is pediatric bipolar disorder due to hyperactivity being described as prolonged periods of mania. Empirical research conducted in 2004 found that "bipolar disorder (in preadolescence) was initially misdiagnosed in 12 out of 24 youths" (Mahoney, 2004). This is a dangerous misdiagnosis due to the vastly different treatment forms. Firstly, ADHD does not require mood stabilizers like pediatric bipolar disorder. Secondly, the stimulants given to treat ADHD have been shown to cause psychosis and exacerbate mania in pediatric bipolar disorder (Wendling, 2009). This misuse of medication can lead to mood episodes, suicidality, and hospitalization. Diagnosis
Diagnosis is made based on a clinical interview by a psychiatrist or other licensed mental health practitioner. There are no blood tests or brain scans to diagnose bipolar disorder. Obtaining information on family history and the use of questionnaires and checklists are helpful in making an accurate diagnosis. Commonly used assessment tools include the K-SADS (Kiddie Schedule for Affective Disorders and Schizophrenia), the Diagnostic Interview Schedule for Children (DISC), and the Child Mania Rating Scale (CMRS).