Stefano Pallanti¹, Bryann R. Baker¹, William Chaplin², Suah Kim¹, Concetta DeCaria¹, Silvia Bernardi¹, Eric Hollander¹.
The 61st Annual Convention of the Society of Biological Psychiatry, Toronto, Canada, May 18th-20th, 2006.
1. Psychiatry, Mount Sinai School of Medicine, New York, NY
2. Psychology, St.John’s University, Queens, NY

Background: Pathological gambling is an impulse control disorder characterized by persistent, maladaptive patterns of gambling behavior afflicting 1.6% of adults in the United States. There is evidence of noradrenergic (NE) dysfunction in PG.

Methods: Thirty-one adult males and females with DSM-IV pathological gambling (PG) and 28 healthy controls (HC) were randomized to single-dose placebo (PL) or oral clonidine (CL) challenges. Blood samples for growth hormone and clonidine levels were obtained.

Results: There was a significant Linear Trend x Group x Challenge interaction (z = 2.575, p = .0100). While the Quadratic Trend x Group x Challenge interaction was not significant (z = 1.644, p = .10), there were significant two-way interactions: a Group x Quadratic Trend interaction (z = 4.645, p < .001) and a Challenge x Quadratic Trend interaction (z = -5.039, p < .001). Tested separately, the quadratic trend in the placebo condition was not significant (z = 1.347, p = .174) but was significant for the clonidine challenge (z = -5.513, p <.001). In comparing the level of log transformed GH between the groups on CL at time 120 (the apex of the curve), the difference in log GH level was significant (Mean for PG = -1.089, Mean for HC = .326; t(54 df) = 3.144, p = .003).

Conclusions: PG subjects demonstrated a markedly blunted growth hormone response to clonidine compared to HC participants. Growth hormone response between PG and HC on placebo did not differ. Pathological gamblers compared to healthy controls have dysregulated noradrenergic function.