About half of Medicaid-covered children and adolescents in Ohio who are in treatment for depression complete their first three months of prescribed antidepressants, and only one-fifth complete the recommended minimum six-month course of drugs to treat depression, new research suggests.

Among those at the highest risk for not completing treatment are adolescents - as opposed to younger children - and minority youths, particularly African Americans, according to the analysis of Medicaid prescription data over a three-year period.

Optimal follow-up visits and adequacy of antidepressant dosing was associated with better adherence during both the acute and continuation phases of treatment.

Though the study was conducted in Ohio, the findings are likely to have broad relevance to Medicaid-eligible children and adolescents across the United States who share similar problems affecting their access to quality mental health care, researchers say.

"There have been a lot of great advances in terms of medication and therapy interventions for depression. The best treatment is a combination of cognitive behavioral therapy and antidepressants," said Cynthia Fontanella, an assistant professor of social work and psychiatry at Ohio State University and lead author of the study.

"But there is a huge gap between the science and what is happening in the real world. And the gap is even greater for kids who live in poverty."

The findings underscore the need for clinicians treating this population to deliver care according to guidelines established by the American Academy of Child and Adolescent Psychiatry, and to develop interventions that improve adherence in the most vulnerable groups, the study authors conclude.

Untreated or poorly treated depression can lead to recurrence, which can increase suicidal behavior and drive up health care costs by increasing the likelihood of hospitalization.

The study is published in the current issue of The Annals of Pharmacotherapy.

Studies suggest that depression affects as many as 20 percent of youths by age 18, and that antidepressant use in people under age 20 has increased three- to five-fold in the past decade. Those experiencing depression are at risk for a number of problems, ranging from school failure and teen pregnancy to substance abuse and suicide.

Compared to youths covered by private insurance, children on Medicaid use more mental health services and are more likely to be prescribed psychotropic medications. They are considered at higher risk for psychiatric disturbances because of the multiple stresses associated with living in poverty.

"This population is very vulnerable," Fontanella said. "Not only do they have to deal with poverty and other psychosocial issues, but also issues commonly associated with poverty, such as transportation limitations, single-parent households and unemployment. All this makes them even more vulnerable to receiving not just a poor quality of care, but poor access to mental health care."

The researchers examined data from Medicaid eligibility and claims files for children and adolescents between the ages of 5 and 17 years who were diagnosed with a new episode of depression between Jan. 1, 2005, and Dec. 30, 2007. They examined cases in which the children were prescribed at least one antidepressant - most of which came from the SSRI (selective serotonin reuptake inhibitor) class of antidepressants - within 30 days of the diagnosis and were continuously enrolled in Medicaid for six months after the prescription date.

Antidepressant adherence measures were derived from the Health Plan Employer Data and Information Set (HEDIS) quality indicators on antidepressant management. Using what is called a medication possession ratio, the researchers predicted that when prescriptions for the youths were filled at a pharmacy for at least 80 percent of the days for which they were prescribed medications, the children were adhering to the treatment.

The cases of 1,650 pediatric depression patients were included in the analysis. Of those, 817, or 49.5 percent, adhered to the treatment during the acute phase - the first three months. About half stopped taking the medicine within one month of starting treatment. And 41.6 percent of the patients who maintained treatment for the first three months also adhered to treatment during the continuation phase of three additional months.

Overall, only 340, or 20.6 percent, of the youths completed a full six months of antidepressant treatment as recommended by the standards set by HEDIS.

"Nonadherence is common," Fontanella said. "With only half of the kids adherent during the first three months and only a fifth adherent for the full six months of treatment, most of these kids are not even meeting the minimum standards of care."

Additional analyses showed that children aged 5 to 12 were more adherent than were adolescents, and non-Hispanic whites were more adherent than minority youths.

Higher rates of adherence during the first three months were associated with better follow-up care and proper dosing of the antidepressants: More than 58 percent of kids who had at least three contacts with a mental health practitioner kept taking their drugs, compared to about one-third of children who had fewer contacts. Similarly, 53.7 percent of children taking what was considered an adequate dose of their antidepressant adhered to treatment, compared to 37.1 percent of youths who received an inadequate dose.

Follow-up and dosing had even greater effects during the later treatment period.

"From a social work and physician perspective, follow-up is critical to monitor not just adherence but also adverse side effects, the potential for increased suicidal behavior and the other negative consequences associated with depression, like poor school performance, relationship issues and a variety of high-risk behaviors," Fontanella said.