Dr. Bhagwagar presented a small but significant study looking at serotonergic function in depression. There is a consensus that serotonin plays a role in episodes of depression. Dr. Bhagwagar's group posed the questions: What happens to serotonergic function after people have recovered from depression, and what probes can be used to investigate serotonergic function? Many other probes of serotonin function have been explored, but none has been both well tolerated and effective across studies. His group decided to try citalopram as a potential probe.

They evaluated 46 subjects. Of the total, 14 had major depressive disorder at the time of the study, although they had been medication free for 3 months. The second subject set of 16 people had a history of major depression in the remote past, defined as at least two episodes but had been well for at least 6 months, and 16 healthy controls.

In a double-blind fashion, researchers gave subjects either 10 mg of intravenous citalopram or normal saline. Blood prolactin and cortisol levels were measured every 15 minutes for about 150 minutes after injection. All subjects received both placebo and citalopram in random order. Results were reported as the subtraction of the citalopram measurements from the placebo measurements.

The research group found that baseline prolactin and cortisol did not differ across study groups. The subjects with current depression and those with recovered depression had significantly lower levels of prolactin and cortisol after injection of citalopram than were found in the control subjects. Subjects with recovered depression did not differ from those with current depression in terms of prolactin level after citalopram. And, subjects with recovered depression had a post-citalopram cortisol level between that of the subjects with current depression and the normal controls.

Dr. Bhagwagar concluded that serotonergic function is disturbed in acute depression and may remain disturbed even after clinical recovery. Further, citalopram seems to have potential as a probe of serotonergic function.