Measuring Chemical Imbalances from Childhood Abuse
Measuring Chemical Imbalances from Childhood Abuse
Background
Bulimia nervosa (BN) is reported to co-occur with childhood abuse and alterations in central serotonin (5-hydroxytryptamine [5-HT]) and cortisol mechanisms. However, findings also link childhood abuse to anomalous 5-HT and cortisol function, and this motivated us to explore relationships between childhood abuse and neurobiological variations in BN.
Methods
Thirty-five bulimic and 25 nonbulimic women were assessed for childhood physical and sexual abuse, eating symptoms, and comorbid psychopathological tendencies. These women provided blood samples for measurement of platelet hydrogen-3–paroxetine binding and serial prolactin and cortisol responses following oral administration of the partial 5-HT agonist meta-chlorophenylpiperazine (m-CPP).
Results
Bulimic women showed markedly lower mean ±SD density (Bmax) of paroxetine-binding sites (631.12 ±341.58) than did normal eaters (1213.00 ±628.74) (t54 = -4.47; P = .001). Paroxetine binding did not vary with childhood abuse. In contrast, measures of peak change on prolactin levels after m-CPP administration (peak prolactin) indicated blunted response in abused bulimic women (7.26 ±7.06), nonabused bulimic women (5.62 ±3.95), and abused women who were normal eaters (5.73 ±5.19) compared with nonabused women who were normal eaters (13.57 ±9.94) (F3,51 = 3.04, P = .04). Furthermore, individuals reporting childhood abuse showed decreased plasma cortisol levels relative to nonabused women who were normal eaters.
Conclusion
Findings imply that BN and childhood abuse are both generally associated with reduced 5-HT tone but that childhood abuse may be somewhat more specifically linked to reduced cortisol levels (ie, hypothalamic-pituitary-adrenal axis) activity.
Findings link traumatic experiences to alterations in central serotonin (5-hydroxytryptamine [5-HT]) and cortisol systems. For example, data have linked posttraumatic stress disorder (PTSD) to reduced platelet binding of the selective 5-HT reuptake inhibitor hydrogen-3–paroxetine ([3H]-paroxetine)1 and childhood abuse (in women with personality disorders) to "blunting" of prolactin and cortisol following the partial 5-HT agonist meta-chlorophenylpiperazine (m-CPP).2 Various traumas have similarly been associated with decreased resting cortisol and altered cortisol stress responses, suggesting posttraumatic alterations of the hypothalamic-pituitary-adrenal (HPA) axis.3, 4
Findings in bulimia nervosa (BN) indicate comparable anomalies. Consistent with reduced 5-HT activity, studies document decreased 5-HT metabolites in cerebrospinal fluid,5 reduced platelet binding of [3H]-paroxetine,6 and blunted prolactin responses to m-CPP.7 Suggesting altered cortisol function, one study8 links atypical depression (ie, with hyperphagia and hypersomnolence) in BN to reduced plasma cortisol; another9 links BN, in general, to decreased nocturnal and postglucose cortisol responses.
Since many bulimic women report childhood sexual and physical abuse,10, 11 one obvious conjecture is that neurobiological and psychopathological variations in...