Income Level May Predict Response
to Depression Treatment
Low-income
people are less likely to respond to treatment
| Archives of
General Psychiatry. Janurary 2, 2006 |
|
|

Newswise — Low-income
people with depression
are less likely to respond to treatment and more
likely to be suicidal than those who have higher
incomes, according to a study in the January issue
of
Archives of General Psychiatry, one of
the JAMA/Archives journals.
Socioeconomic factors, including income, education
and occupation, have long been linked to health
status, illness and death. Research has shown that
people with lower socioeconomic status (SES) are
more likely to develop a depressive illness and
that their depression is more severe than that
of people higher on the SES scale. Several studies
have hypothesized that socioeconomic factors, including
income and education, would also affect how people
respond to medications and other therapies for
depression, but have ultimately proved inconclusive,
according to background information in the article.
Alex Cohen, Ph.D., of Harvard Medical School,
Boston, and colleagues reanalyzed two previous
clinical trials funded by the National Institute
of Mental Health and conducted at the University
of Pittsburgh. The 248 participants were all 59
years or older and receiving antidepressant medications
combined with psychotherapy. Their education levels
were assessed at the beginning of the original
studies. Median annual household income for their
areas was obtained from the U.S. Census Bureau.
Low-income was defined as less than $25,000, middle-income
between $25,000 and $50,000 and high-income more
than $50,000. The subjects’ depressive symptoms
and response to treatment were measured weekly.
When the authors controlled for demographic factors,
such as age and gender, and baseline clinical characteristics,
including recurrence of depression and age at onset,
they found that people in areas defined as middle-income
were significantly more likely to respond to treatment
than those in the low-income group. High-income
people were only marginally more likely to respond
to treatment than middle-income residents, but
as a group, high- and middle-income study participants
were significantly more likely to respond than
those in low-income areas.
In addition, people in low-income areas were about
twice as likely as those in middle-income areas
and two and a half times as likely as those in
high-income tracts to be suicidal, “suggesting
an inverse relationship between the median household
income of the neighborhoods in which subjects resided
and suicidality,” the authors write.
The authors found that years of education did
not affect treatment response or suicidality in
this particular study group. “When the older
subjects in our study came of age, economic and
social success in the industrial economy was not
so dependent on education,” they write. “Thus,
we speculate that years of education is a less
accurate measure of SES in this sample.”
Based on their findings, the authors “suggest
that future clinical trials routinely gather data
on individual income, educational degrees earned,
occupation and aspects of the broader social environment
such as social capital. However, to transform evidence
into knowledge that will inform the treatment of
depression, it is essential that future research
examines all of the factors (for example, neighborhoods,
stress, social support, race/ethnicity or income
inequalities) that may mediate the association
between SES and clinical outcomes.”
Editor’s Note: This study was supported
in part by grants from the National Institute of
Mental Health, Rockville, Md