Could GHRH Keep Seniors Mentally Sharp?

Could injections of growth hormone-releasing hormone (GHRH) keep seniors sharp regardless of whether they have mild cognitive impairment? An intriguing study published recently in the Archives of Neurology suggests that they could. The lead scientist was Michael Vitiello, Ph.D., a professor of psychiatry at the University of Washington. Vitiello and colleagues first found in a six-month study of 89 healthy older adults that daily injections of GHRH improved executive function significantly more than a placebo did. They have now now confirmed those results in a larger study and extended them to subjects with mild cognitive impairment.

Their sample included 137 older adults aged 55 to 87, of whom 76 had normal cognitive status and 61 had mild cognitive impairment. The subjects self-administered daily subcutaneous injections of a synthetic analog of human GHRH (1 mg/d) or a placebo 30 minutes before bedtime for 20 weeks. At baseline, at weeks 10 and 20 of treatment, and after a 10-week washout period (week 30), cognitive tests were administered. The executive-function results for the GHRH group were significantly better than for the placebo group. And even though the healthy adults outperformed those with mild cognitive impairment, the cognitive benefit of GHRH relative to placebo was comparable for both groups.

"This is a well-conducted trial by an outstanding group of investigators with expertise in cognitive disorders of later life," APA President Dilip Jeste, M.D., chair in aging at the University of California, San Diego, told Psychiatric News.

Look for more information about this study in an upcoming issue of Psychiatric News.

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