Studies have linked bulimia nervosa (BN) to alterations in brain serotonin (5-hydroxytryptamine: 5-HT) activity and to heightened propensity for parasuicidality and self-injuriousness. The coincidence of self-destructiveness and 5-HT abnormality in BN is of interest, given documentation (in various populations) of an inverse association between 5-HT activity and potential for self-harm. The present study examined the connection between 5-HT status and self-destructiveness in BN. Structured interviews and self-report questionnaires were used to assess 40 bulimic and 21 normal-eater women for: (a) history of parasuicidal or self-injurious acts; and (b) mood and impulse-regulation problems. We then applied tests, presumed to reflect 5-HT function, of serial prolactin (PRL) and cortisol (CORT) responses after oral administration of the partial 5-HT agonist, meta-chlorophenylpiperazine (m-CPP). Relative to non-bulimic women, bulimic women (on average) showed blunting of PRL and CORT following m-CPP. The blunting of neuroendocrine responses was, however, most remarkable in bulimic women with a history of self-destructiveness. These findings suggest that some serotonergic anomalies reported in BN sufferers (i.e. reduced neuroendocrine response after m-CPP) may be most characteristic of individuals in the population showing clear-cut self-destructive potential.
Evidence suggests that bulimia nervosa (BN) coincides with alterations in central serotonin (5-hydroxytryptamine: 5-HT) activity (Brewerton, 1995 and Wolfe et al., 1997). Studies in bulimic patients have documented decreased 5-HT metabolites in cerebrospinal fluid (CSF: Jimerson et al., 1992), reduced platelet binding of the 5-HT uptake inhibitors [3H]imipramine (Marazziti et al., 1988) and [3H]paroxetine (Steiger et al., 2000) and blunted prolactin (PRL) responses to 5-HT agonists or partial agonists (Brewerton et al., 1992 and Levitan et al., 1997). Data from independent studies show bulimic patients to display prominent parasuicidality or self-mutilation behaviours (Mitchell et al., 1986) and some findings (most based on very small samples) suggest that impulsive symptoms in BN may correspond to greater abnormality on various indices of 5-HT functioning (Steiger et al., 2001, Verkes et al., 1996 and Waller et al., 1996).
Coincidence of self-destructiveness and 5-HT abnormality in BN is intriguing, given documentation in other psychiatric populations of a systematic (inverse) association between 5-HT activity and self-destructive (i.e. parasuicidal or self-injurious) potentials. For example, research in depressed and personality-disordered patients has linked suicidal, self-injurious and/or impulsive–aggressive behaviors to: (a) low CSF 5-hydroxyindoleacetic acid (5-HIAA: Åsberg et al., 1987 and Lopez-Ibor et al., 1985); (b) decreased 5-HT and imipramine binding in post-mortem brain tissue (Stanley et al., 1982); (c) reduced PRL responses following the 5-HT agonist d,l-fenfluramine (Coccaro et al., 1989 and New et al., 1997); and (d) blunted metabolic responses, measured by positron emission tomography, following administration of the 5-HT agonist d,l-fenfluramine (Siever et al., 1999 and Soloff et al., 2000). Such findings motivated us to explore the association between serotonin status and self-harming behaviors in BN.
In the present study, we assessed 5-HT function by measuring PRL and cortisol (CORT) responses following oral administration of the partial 5-HT agonist, meta-chlorophenylpiperazine (m-CPP). The rationale for this procedure rests upon the assumption that stimulation with 5-HT agents results in increased release of PRL (via serotonergic pathways into the pituitary) and CORT (via indirect hypothalamic–pituitary–adrenal axis connections). As it binds with highest affinity to 5-HT2c receptors and lesser affinity to 5-HT1a and alpha2-noradrenergic receptors, m-CPP is thought to constitute a fairly specific probe of postsynaptic 5-HT function (Yatham and Steiner, 1993). The PRL and CORT response following m-CPP administration has been used to study 5-HT neurotransmission in several previous studies on BN (Brewerton et al., 1992, Levitan et al., 1997 and Steiger et al., 2001).
