Associations between use of cocaine, amphetamines, or psychedelics and psychotic symptoms in a community sample

Abstract

Associations between psychotic symptoms and use of cocaine, and/or psychedelics in adolescents and young adults call for further studies to elucidate risk factors and developmental pathways.

The prevalence of substance use disorders and psychiatric disorders as a function of psychotic symptoms

“…First, we did not observe increased rates of hallucinogen dependence among CurrSx, which contrasts with the significant relationship between psychedelic drug use and psychotic symptoms reported in previous studies (Kuzenko et al, 2011). However, it is worth noting that Kuzenko et al (2011) operationalized “substance use” as having used a particular drug five times or more in one’s lifetime, whereas the current study assessed DSM-IV diagnoses of substance dependence based on responses to a structured interview. Similarly, we did not observe the increased prevalence of cannabis use among individuals with psychotic symptoms, as is commonly reported in the literature (Rosller et al, 2012; Dekker et al, 2009).…”

“…The increased prevalence of amphetamine dependence (as well as cocaine dependence before controlling for age) among CurrSx is comparable to the findings reported by Kuzenko et al (2011), who reported elevated rates of cocaine use among individuals with a history of two or more psychotic symptoms in a community sample. Neither our study, nor Kuzenko et al examined specific mechanisms driving the apparent relationship between psychotic symptoms and the use of cocaine and other stimulants in particular, as opposed to other addictive substances.…”

“…Incidence of psychotic symptoms in the general population has been reported to range from 4.8% to 8.3% depending on the specific symptom examined (Nuevo et al, 2012). Substance users represent one group with particularly high rates of psychotic symptoms (Kuzenko et al, 2011; Smith et al, 2009), and these symptoms can pose significant challenges during substance use treatment. Indeed, individuals with substance use disorders and co-occurring psychosis frequently evidence less motivation to change, reduced treatment engagement, and an increased likelihood of dropping out of treatment prematurely relative to individuals with substance use disorders alone (for review, see Horsfall et al, 2009).…”

“…In the few studies that have examined non-substance induced psychosis among substance users, the studies were often limited to a narrow set of drug classes (e.g., Dekker et al, 2009; Kuzenko et al, 2011; Salo et al, 2011; Lichlyter et al, 2011) and most did not address key variables such as psychiatric comorbidity. One study that did assess a wide range of drug classes and psychiatric comorbidities reported elevated rates of dependence and comorbidity among individuals endorsing psychotic symptoms (McMillan et al, 2009).…”

“…This removal of several barriers to participation and the subsequent impact on differential self-selection may be especially important in a study focused on psychotic symptoms. The purpose of the current study was to assess results presented in previous research indicating that individuals endorsing psychotic symptoms evince a greater likelihood of meeting dependence criteria for several substances including marijuana (Rosller et al, 2012; Dekker et al, 2009), cocaine (Kuzenko et al, 2011), amphetamines (Lichlyter et al, 2011), as well as Poly-drug use (Rosller et al, 2012), within the context of the improvements in methodology listed previously. Additionally, we aimed to assess previous results indicating that individuals endorsing psychotic symptoms often meet criteria for mood and anxiety disorders at an increased rate relative to individuals with no history of psychotic symptoms (Michail and Birchwood, 2009; Koreen et al, 1993).…”