WEDNESDAY, May 7 (HealthDay News) -- New treatments for a type of depression in the elderly related to blood vessels -- called vascular depression -- are under development, and researchers have discovered why some patients with this condition fail to respond to current medications.

Details of the findings were to be presented Wednesday during a news conference by researchers taking part in U.S. National Institute of Mental Health symposiums at the annual meeting of the American Psychiatric Association, in Washington, D.C.

Vascular depression is a recently recognized type of depression that usually develops in patients older than age 60. The condition is associated with loss of blood supply to the brain.

"Mental health practitioners and patients should be aware of the relationship between vascular problems and depression, and should understand the value of preventing vascular changes that might lead to difficult-to-treat depressions, for example, through early recognition and treatment of high blood pressure," Dr. John Newcomer, of Washington University in St. Louis, said in a prepared statement.

Several research teams are reporting progress in understanding and treating vascular depression.

Dr. George Alexopoulos of Weill Cornell Medical College in White Plains, N.Y., and colleagues are investigating the specific brain abnormalities associated with blood vessel problems. Using a new MRI technique called diffusion tensor imaging, the researchers found that, in late life depression, higher blood pressure readings are linked to tiny white matter abnormalities, mainly in the brain's frontal lobes and in subcortical areas. Some of these abnormalities are associated with impairment in specific frontal lobe functions.

The same team also found that patients with major depression treated with the antidepressant citalopram were less likely to recover if they had cardiovascular disease or did poorly on a test of cognition requiring frontal lobe function.

They also found that patients with major depression who took the antidepressant escitalopram (which is more potent than citalopram) were less likely to recover if they had more of the tiny structural abnormalities in several areas of the frontal lobes and in subcortical structures.

"With further refinement, the findings may improve physicians' ability to predict who will fail to respond to antidepressants. Such patients may need close follow-up and different treatments such as psychotherapy or novel medications. Second, our findings can be used in the development of new treatments for those who do not respond to classical antidepressants," Alexopoulos said in a prepared statement.

He and his team are currently studying how parts of the frontal lobes are activated when depressed patients do cognitive tasks that activate this area.

Preliminary findings show that depressed older patients cannot activate these frontal lobe parts as efficiently as non-depressed older adults," Alexopoulos said.

In other research, a team at the University of Iowa found that vascular depression can be treated with an experimental technique called repetitive transcranial magnetic stimulation (rTMS). They found that rTMS led to better remission rates than standard medication treatment, and that increasing the number of magnetic pulses significantly improved remission rates.

"These findings suggest that this new method of treatment may be particularly useful for these late life onset depressions and that even greater response rates might be achieved by utilizing more pulses of magnetic stimulation," Dr. Robert Robinson, a professor of psychiatry, said in a prepared statement.

In other reports presented at the conference, scientists urged caution in the use of antipsychotic drugs in elderly people and other patients in order to minimize metabolic, heart and stroke risks.

More information

The American Academy of Family Physicians has more about older adults and depression.