BOCA RATON, FLA. – Residual anxiety symptoms and sleep disturbances predicted recurrence of late-life depression in a study presented as a poster at a meeting of the New Clinical Drug Evaluation Unit sponsored by the National Institute of Mental Health.
“We know residual symptoms are important. But no study has dissected which residual symptoms are predictive of who is still depressed,” Dr. Alexandre Y. Dombrovski said.
Dr. Dombrovski and his associates assessed data for participants in a randomized, clinical trial. All patients had unipolar depression and were aged 70 years or older. A total of 116 participants were in remission, and remained stable during open pharmacotherapy and interpersonal psychotherapy. Those participants were studied further.
“We looked at core mood symptoms, sleep disturbances, and anxiety over 2 years for predictors of recurrence,” said Dr. Dombrovski of the University of Pittsburgh Medical Center's Western Psychiatric Institute and Clinic.
Recurrence was defined as a score greater than 14 on the Hamilton Depression Rating Scale (HAM-D) and meeting DSM-IV criteria for a major depressive episode.
This was a secondary analysis of a depression maintenance study that compared clinical management with monthly maintenance interpersonal psychotherapy, and paroxetine (Paxil) pharmacotherapy with placebo, he said.
Depressed mood, guilt, suicidality, energy/interests were the core mood symptoms rated with the HAM-D. Also, researchers used the HAM-D to assess early, middle, and/or late insomnia, as well as anxiety symptoms (agitation, psychic and somatic anxiety, hypochondriasis). The Pittsburgh Sleep Quality Index (PSQI) was used to gauge sleep quality.
“We found in these patients that persisting anxiety symptoms predicted early return of depression,” Dr. Dombrovski said.
Total burden of residual anxiety symptoms was the strongest predictor of depression recurrence, nearly doubling the risk, compared with nonanxious participants. “This confirmed our hypothesis and our earlier study,” he said (Am. J. Geriatr. Psychiatry 2006;14:550–4).
Sleep disturbance also was predictive, but only on the PSQI and not the HAM-D measure, univariate analyses showed. In a multiple Cox regression model that controlled for patient assignment to either paroxetine or placebo, HAM-D residual anxiety and PSQI residual sleep disturbance remained significant predictors, Dr. Dombrovski said.
He said that for patients with late-life depression, physicians should identify the subgroup with enduring anxiety, because it is a marker for risk of recurrence. The study was funded by the National Institutes of Health and the John H. Hartford Foundation. The meeting was sponsored by the American Society for Clinical Psychopharmacology.