SPECIFICITY OF THE PYRIDOSTIGMINE GROWTH-HORMONE CHALLENGE IN THE DIAGNOSIS OF DEPRESSION

Acetylcholine is a neurotransmitter that has been implicated in the pa thophysiology of major depression, This is supported by the enhanced g rowth hormone (GH) release in response to pyridostigmine (PYD) challen ge in depressed subjects relative to healthy comparison subjects. The nim of this study is to examine the specificity of the PYD/GH challeng e in the diagnosis of depression, Pyridostigmine 120 mg orally, was ad ministered to a total of 116 physically healthy subjects. Growth hormo ne responses were studied in 38 patients with (DSM-III-R) major depres sion, 13 subjects with panic disorder, 9 subjects with schizophrenia, 10 recently detoxified alcoholics, and a comparison group of 45 health y volunteers. Mean Delta CH (the difference between basal and maximal GH following PYD) was significantly, greater than comparison subjects in patients with major depression. Responses observed in patients with schizophrenia and alcohol dependence syndrome did not differ from the comparison group, Those patients with panic disorder and a high Hamil ton depression score had an enhanced Delta GH. The sensitivity of the PYD/GH rest was 63% for major depression. These results indicate that the PYD/GH test may help distinguish depression from schizophrenia, al cohol-dependence syndrome, or panic disorder with a low Hamilton depre ssion score. (C) 1997 Society of Biological Psychiatry.