Plasma Insulin, Tryptophan and Serotonin Levels during the Glucose Tolerance Test among Habitually Violent and Impulsive Offenders

Abstract

Insulin activity in plasma and the concentrations of tryptophan and serotonin were measured during the glucose tolerance test (GTT) in habitually violent and impulsive male offenders and in psychiatric personnel as controls. Insulin was enhanced in the intermittent explosive disorder; at the same time the concentration of plasma tryptophan and the ratio of tryptophan to large neutral amino acids were on a high level and tryptophan even increased in many cases during GTT. Serotonin values did not differ. Many offenders with enhanced insulin secretion displayed abnormal neuroglycopenic symptoms during GTT.

Laboratory-Measured Aggressive Behavior of Women Acute Tryptophan Depletion and Augmentation

“…Post hoc analyses produced an interesting preliminary result showing that when the women were divided into two groups-high and low fasting control plasma Trp-there was a distinct difference in aggressive responsivity to CNS 5-HT manipulation. Similar results with men have established a relationship between higher baseline plasma Trp and elevated aggressive behavior (Eriksson and Lidberg 1997;Møller et al 1996;Virkkunen and Närvänen 1987;Wingrove et al 1999). The results of this study show that it was the high fasting control plasma Trp women who increased aggressive responding under depletion conditions; however, unlike the men, these women also showed significant decreases in aggression when plasma Trp was augmented.…”

“…Serotonin dysfunction has been correlated with impulsive and violent criminal behaviors (Brown et al , 1982Lidberg et al 1985;Limson et al, 1991;Virkkunen and Närvänen 1987;Virkkunen et al 1994aVirkkunen et al , 1994b, alcohol abuse and dependence (Badawy et al 1995;Ballenger et al 1979;Banki 1981;Borg et al 1985;Moss 1987;Roy and Linnoila 1989), Gilles de la Tourette's syndrome (Butler et al 1979;Cohen et al 1978Cohen et al , 1979, bulimia (Jimerson et al 1990(Jimerson et al , 1992, and suicide attempts (Asberg et al 1976(Asberg et al , 1986Banki and Arato 1983;López-Ibor et al 1985), as well as with children institutionalized for aggressive behavior (Kruesi 1989;Kruesi et al 1990Kruesi et al , 1992.…”

“…Because studies have shown that men reporting higher hostility and aggression levels also have higher baseline levels of plasma Trp (Eriksson and Lidberg 1997;Møller et al 1996;Virkkunen and Närvänen 1987;Wingrove et al 1999), the 10 women who provided blood samples were divided equally into two groups: low (M ϭ 6.13 g/ml, SD ϭ 0.63) and high (M ϭ 7.54 g/ml, SD ϭ 0.36) fasting control plasma total Trp using a median split of Trp levels measured on the FR day. These fasting control plasma Trp concentrations fall into the range of values found in other studies in which measurements were taken after 24 h of a low-Trp diet and overnight fasting (Carpenter et al 1998;Møller 1981 Figure 2, a 2 ϫ 3 ϫ 3 (high/low group ϫ treatment ϫ time) repeated measures univariate ANOVA revealed that aggressive responding (point subtraction B responses) was diminished by Tϩ and increased by TϪ treatments across the sessions, as indicated by the main effects of both treatment and time [F(2,16) ϭ 5.99, H-F p ϭ .02, f ϭ 0.87; F(2,16) ϭ 3.66, p ϭ .049, f ϭ 0.68, respectively], but the high group was affected by both the Tϩ and the TϪ treatments whereas the low group was not [group ϫ treatment interaction, F(2,16) ϭ 5.14, p ϭ .02, f ϭ 0.48].…”

CSF 5-HIAA and Nighttime Activity in Free-Ranging Primates

“…Serotonin-mediated behavioral deficits are thought to result in part from an inability to maintain a homeostatic response in a number of physiological systems (Virkkunen et al 1989a;Virkkunen and Narvanen 1987;Virkkunen et al 1994). Various lines of evidence indicate that central serotonin neurotransmission contributes to regulation of sleep-wake cycles and circadian activity patterns.…”

“…Research using nonhuman primates has replicated and extended many of these findings (Higley et al 1996a;Higley et al 1992a;Higley et al 1996b;Kaplan et al 1994;Mehlman et al 1995;Mehlman et al 1994;Mehlman et al 1997;Raleigh 1987;Raleigh et al 1983a;Raleigh et al 1983b;Raleigh et al 1980;Raleigh and McGuire 1994). Further, this research has demonstrated that inter-individual differences in CSF 5-HIAA concentrations are stable across time and experimental settings and can be attributed to genetic and early environmental influences that produce lasting modifications in the CNS serotonin response (Higley et al 1996b;Higley et al 1994;Higley et al 1996a).Serotonin-mediated behavioral deficits are thought to result in part from an inability to maintain a homeostatic response in a number of physiological systems (Virkkunen et al 1989a;Virkkunen and Narvanen 1987;Virkkunen et al 1994). Various lines of evidence indicate that central serotonin neurotransmission contributes to regulation of sleep-wake cycles and circadian activity patterns.…”