SAN FRANCISCO – A new type of scale for determining remission from depression performed well, compared with conventional measures in a study of 153 outpatients being treated for depression.
At baseline and after 3-4 months of treatment, patients completed the experimental Remission From Depression Questionnaire (RDQ) and the commonly used Quick Inventory of Depressive Symptomatology (QIDS). They were assessed using the 17-item Hamilton Depression Rating Scale (HAM-D). The QIDS and HAM-D focus on symptomatology, while the 41-item RDQ is a broader measure that includes other factors that patients have identified in previous studies as being important elements of remission, Dr. Mark Zimmerman said at the annual meeting of the American Psychiatric Association.
Dr. Mark Zimmerman
The effect size for all three scales were the same, meaning that the three tools were equally sensitive to change in depression, reported Dr. Zimmerman of Brown University, Providence, R.I.
Each of the seven subscales of the RDQ were sensitive to change, including subscales for symptoms of depression, other symptoms (such as anxiety or irritability), coping ability, positive mental health, functioning, life satisfaction, and general sense of well-being.
The RDQ scores were associated with self-perceived remission even after controlling for QIDS scores. In contrast, QIDS scores were associated with self-perceived remission, but not after controlling for the RDQ scores. "The RDQ is picking up variance in whether or not patients believe they are in remission above and beyond that accounted for by symptoms alone," said Dr. Zimmerman, also director of outpatient psychiatry at Rhode Island Hospital, Providence.
Historically, studies have found wide variability in the definition of remission from depression and in the terms used to describe it. A 1991 consensus conference defined remission as a score of 7 or less on the 17-item HAM-D. One of the limits of this and other definitions of remission is that they are completely symptom based with no consideration of other factors that might be important in determining how patients are doing during treatment, he said.
Dr. Zimmerman and his associates have been studying a broader concept of depression remission in studies over the past decade. "Just what this field needs – another measure to assess depression, because there aren’t enough of them already," he said sarcastically.
They initially surveyed 535 depressed outpatients to find out what they consider to be important aspects in determining remission. Among the 16 items they rated, symptom resolution didn’t make the top 4. The top factors rated by patients as important were the presence of positive mental health (selected by 77% of participants), feeling like one’s usual, normal self (76%); return to one’s usual level of functioning (74%); and feeling in emotional control (72%). When asked to choose the most important factor determining remission, 17% chose the presence of positive mental health, 14% chose feeling like one’s usual self, 11% picked a general sense of well-being, and only 10% pointed to the absence of symptoms of depression (Am. J. Psychiatry 2006;163:148-50).
"There seems to be a disconnect between what researchers have been doing all these years, which is defining remission purely in symptom terms, and what patients say are the most important considerations that they have in determining whether or not they’re in remission," he said.
Dr. Zimmerman and his associates next surveyed 514 outpatients being treated for major depressive disorder. They found that patients’ ratings of the severity of their depression, how much their symptoms have interfered with their lives or caused them difficulties, and their overall quality of life were significantly and independently associated with their view of whether or not they were in remission. (J. Psychiatr. Res. 2008;42:797-801).
The findings of these first two studies and subsequent focus groups led the investigators to develop the RDQ. In a study of 102 depressed outpatients, patients felt the RDQ was more accurate than was the symptom-based QIDS in assessing their goals and progress in treatment, and they preferred the RDQ, Dr. Zimmerman said (Ann. Clin. Psych. 2011;23:208-12).
He and his associates tested the RDQ’s reliability and validity in a study of 274 depressed outpatients in ongoing treatment, 60 of whom completed the RDQ twice to assess reliability. Patients filled out the RDQ and the QIDS, and were rated on the 17-item HAM-D and other measures. The RDQ proved to be reliable, with good internal consistency. Approximately 50% of patients were in self-reported remission according to the various measures. After researchers controlled for depression symptom severity, the RDQ identified patients who considered themselves to be in remission for reasons above and beyond symptoms status (J. Psychiatr. Res. 2013;47:78-82).