Washington: A two-drug combination can help treat older adults with clinical depression when an antidepressant alone is not effective, scientists say.
A multicenter clinical trial that included researchers from Washington University School of Medicine in St Louis indicates that adding a second drug – an antipsychotic medication – can relieve depression in many older adults whose symptoms don’t resolve after treatment with a standard antidepressant drug. The findings come from a study of 468 people over age 60 and diagnosed with depression. Previous research in younger patients with depression showed that adding a low dose of the antipsychotic drug aripiprazole (brand name Abilify) helped relieve symptoms of depression when an antidepressant alone was not effective.
But the new study is the first to show that the same strategy also works in older adults. The two-drug combination relieved depression in a significant number of patients and also reduced the likelihood that they would have suicidal thoughts. “It’s important to remember that older adults may not respond to medications in the same way as younger adults,” said first author Eric J Lenze, a Washington University professor of psychiatry. “There are age-related changes in the brain and body that suggest certain treatments may work differently, in terms of benefits and side effects, in older adults,” Lenze said. Lenze, who directs the Healthy Mind Lab at Washington University School of Medicine, was the principal investigator in St Louis. Patients were also treated at the University of Pittsburgh School of Medicine and at the Centre for Addiction and Mental Health (CAMH) in Toronto.
Each study participant received an extended-release formulation of the antidepressant drug venlafaxine (brand name Effexor XR) for 12 weeks. About half of these patients still were clinically depressed after 12 weeks of treatment. So for the second phase of the study, patients who initially did not respond to the venlafaxine continued to receive the drug along with aripiprazole or a placebo. Aripiprazole often is prescribed to treat schizophrenia and manic episodes associated with bipolar disorder. The two-drug combination led to a remission of depression in 44 per cent of the treatment-resistant patients, compared with only 29 per cent of those who had received the placebo.
Some patients who took the two-drug combination experienced restlessness. Others developed some stiffness, called mild Parkinsonism. But the side effects tended to be mild and short-lived. “The potential benefits outweighed the side effects,” Lenze said, adding that side effects that investigators expected to see, such as weight gain and metabolic problems, never occurred. The study was published in The Lancet journal.
