N-acetylcysteine as treatment for self-injurious behavior in a child with autism.

Abstract

[Author Affiliation]Sarah Marler. Department of Child and Adolescent Psychiatry, Vanderbilt University Medical Center, Nashville, Tennessee.Kevin B. Sanders. Department of Child and Adolescent Psychiatry, Vanderbilt University Medical Center, Nashville, Tennessee.Jeremy Veenstra-VanderWeele. Department of Child and Adolescent Psychiatry, Vanderbilt University Medical Center, Nashville, Tennessee.Address correspondence to: Jeremy Veenstra-VanderWeele, MD, Associate Professor of Psychiatry, Pediatrics, and Pharmacology, Kennedy Center for Research on Human Development, Vanderbilt Brain Institute, 7158 Medical Research Building III, 465 21st Ave. S. Nashville, TN 37232, E-mail: j.vvw@vanderbilt.eduTo The Editor:Self-injurious behaviors (SIB), including skin picking/scratching, self-biting, and head banging have been reported to occur in as many as 50% of children with autism spectrum disorders (ASD) (Rojahn 1994; Richards et al. 2012). More than 14% reportedly exhibit severe SIB, which indicates that the behavior results in functional impairment or life-threatening injury (Baghdadli et al. 2003; Duerden et al. 2012). An inverse relationship exists between the presence SIB and the severity of intellectual impairment (Berkson 1983; Rojahn and Esbensen 2002; Symons et al. 2005; Hillery and Dodd 2007), and SIB frequently co-occurs in many syndromes often associated with intellectual/developmental disabilities, such as Lesch-Nyhan syndrome (Nyhan and Wong 1996), Rett syndrome (Deb 1998), Prader-Willi syndrome (Dykens and Kasari 1997), and Fragile X syndrome (Symons et al. 2003). Numerous hypotheses regarding the etiology of SIB have emerged over the years, including (but not limited to) SIB as a symptom of physical discomfort/organic illness, the result of a neurochemical imbalance, a learned behavior, a form of communication, or a form of self-stimulation (Rana et al. 2013).SIB is often approached and treated as a discrete behavior, independent from other maladaptive behaviors (Bodfish and Lewis 2002); however, self-injury in ASD is generally associated with other impairing symptoms, including high levels of impulsivity, irritability, and stereotypies, paired with lower intellectual functioning (Matson et al. 2008; Richman et al. 2013). SIB in children with ASD are commonly targeted for treatment by means of pharmacology (Soorya et al. 2008), communication strategies (Johnson and Rodriguez 2013), and behavioral modification (Minshawi 2008 Devlin et al. 2011). To date, no single intervention strategy for SIB has emerged as consistently effective (King 2000; Lang et al. 2010; Oliver and Richards 2010).Limited data support the use of any medication class specifically for SIB, whether in autism or other developmental disabilities (King 2000; Rana et al. 2013). A number of medications are sometimes used to try to address self-injury, including serotonin reuptake inhibitors (SRIs), atypical antipsychotics, α agonists, and opioid antagonists. The most frequently used medications overall for individuals with ASD have been SRIs (Aman et al. 2005), although these medications have shown ambiguous efficacy in children with ASD (McDougle et al 2000; King et al. 2009; Williams et al. 2013), as well as in pathological skin picking (Simeon et al 1997; Bloch et al 2001; Arbabi et al. 2008). Atypical antipsychotics have been the second most frequently used pharmacological intervention for children with ASD (Aman et al. 2005). Although efficacy in the treatment of irritability, and compulsive and disruptive behaviors has been demonstrated in large-scale, randomized controlled trials (RCTs), little evidence exists for specific benefit for SIB (McCracken et al. 2002; Shea et al. 2004; McDougle et al. 2005; Marcus et al. 2009; Owen et al. 2009). Atypical antipsychotics have also not demonstrated efficacy in reducing SIB in adults with intellectual disability, with or without ASD (Ruedrich et al 2008). …