Characteristics and outcomes of young people with substance induced psychotic disorder
Introduction
A small but significant proportion of individuals presenting with a first episode of psychosis (FEP) will receive a diagnosis of substance induced psychotic disorder (SIPD). This diagnosis has attracted criticism, as a large proportion of individuals with a psychotic disorder will also have a concurrent substance abuse disorder (Jablensky et al., 2000; Wilson et al., 2017) and thus accurate diagnosis can be difficult (Mathias et al., 2008). Despite this, individuals with a diagnosis of SIPD are often excluded from research studies (Jorgensen et al., 2000), have shorter periods of clinical care (National Institute for Mental Health in England, 2008), and have longer delays to care post first referral to services (Kirkbride et al., 2017). This practice is however counter-intuitive, considering that SIPD is a psychotic disorder which warrants appropriate treatment, and that the diagnosis is associated with a high risk of subsequently developing schizophrenia. Specifically, between 25 and 46% of individuals with SIPD transition to a schizophrenia spectrum disorder, often within three years of first service presentation (Arendt et al., 2005; Caton et al., 2007; Crebbin et al., 2009; Niemi-Pynttari et al., 2013).
In addition to this, individuals with SIPD present with more severe depressive symptoms and suicidal ideation (Caton et al., 2005; Nunez and Gurpegui, 2002), and similar levels of positive symptoms, quality of life, functioning and relapse rates compared to individuals with other psychotic disorders (Thompson et al., 2016), though are more likely to lose contact with mental health services (Crebbin et al., 2009). Further, individuals with a concurrent psychotic disorder and cannabis abuse disorder are more likely to present at a younger age (Large et al., 2011; O'Donoghue et al., 2015) and any substance misuse has been associated with increased risk of inpatient admission and earlier relapse of symptoms for those with FEP (Wade et al., 2006). All of these clinical factors provide a strong justification for a need for care within this FEP sub-group, however contention still exists about where those diagnosed with SIPD should receive treatment, what treatments they should receive, and for how long.
This study aims to add to the current literature with an epidemiological longitudinal examination of those presenting to an early intervention service with a SIPD compared to those with other affective or non-affective first episodes of psychosis. Specifically, the study aims to determine:
- (i)
the proportion of young people presenting with a SIPD
- (ii)
whether demographic and clinical characteristics are associated with a diagnosis of a substance induced psychosis
- (iii)
rates of remission and relapse in the SIPD group compared to other FEP diagnoses
- (iv)
functional outcomes, in regards to education and employment, in the SIPD group
- (v)
the proportion of those who have a diagnosis of SIPD at presentation and who later fulfil criteria for a different psychotic disorder
Section snippets
Participants
This study included an epidemiological cohort of 544 young people with a diagnosis of a first episode of psychosis (FEP) who received treatment at the Early Psychosis Prevention and Intervention Centre (EPPIC).
Setting
EPPIC is a comprehensive treatment program within Orygen Youth Health (OYH) for young people aged 15 to 25 years with a FEP in the north-western regions of Melbourne, Australia. This catchment area covers more than one million people and EPPIC provides services to approximately 400 people
Demographic characteristics of cohort
The cohort consisted of 544 individuals, 325 of whom were male (59.7%). At service entry, the mean age of the cohort was 19.5 years (sd ± 2.9). The median length of time in service was 84 weeks (I.Q.R. 53, 101). Table 1 details the demographic and clinical characteristics of the cohort.
Diagnosis and duration of untreated psychosis (DUP)
Fifty-six individuals in the cohort had a diagnosis of a SIPD (10.3%) at three months of service engagement. A complete list of diagnoses is detailed in Table 1. The mean DUP in the cohort was 25.4 weeks
Discussion
There are a number of important findings from this study. First, there were minimal differences in the clinical characteristics and outcomes of those with a SIPD compared to other psychotic disorders. As would be expected, those with a SIPD were more likely to have a concurrent substance abuse disorder, but notably, there was no difference in regards to psychotic symptom severity, remission and relapse rates, and DUP. In the only difference between groups, the SIPD group faired worse in regard
Conclusion
Young people with SIPD experience similar severity of psychotic symptoms and rates of relapse and remission to those with other FEP diagnoses, though experience poorer vocational outcomes as explained by cannabis use. This study does not lend evidence to the widely held view that less intensive treatments are required for those with SIPD and suggests such individuals should be an important focus of engagement and treatment within early intervention for psychosis services. Continued review of
Conflict of interest
All authors declare that they have no conflicts of interest.
Contributors
Jessica O'Connell conducted literature searches and wrote the first draft of the manuscript. Monica Sunwoo and Patrick McGorry assisted literature searches and contributed to the writing of the introduction and discussion. Brian O'Donoghue designed the study, wrote the protocol, and conducted data analysis. All authors contributed to and have approved the final manuscript.
Role of the funding bodies
Dr. Brian O'Donoghue is a recipient of a NHMRC Early Career Fellowship.
Acknowledgments
We thank Meghan Bowtell, Scott Eaton, Melissa Bardell-Williams, Linglee Downey, and Kristen Thien who completed data collection for this study.
References (27)
- et al.
Differentiating first episode substance induced and primary psychotic disorders with concurrent substance use in young people
Schizophr. Res.
(2012) - et al.
Primary psychosis with comorbid drug abuse and drug-induced psychosis: diagnostic and clinical evaluation at follow up
Asian J. Psychiatr.
(2017) - et al.
Environmental factors and the age at onset in first episode psychosis
Schizophr. Res.
(2015) - et al.
Measuring schizophrenia remission in clinical practice
Can. J. Psychiatr.
(2008) Diagnostic and Statistical Manual of Mental Disorders
(2000)- et al.
Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders: follow-up study of 535 incident cases
Br. J. Psychiatry
(2005) - et al.
Familial predisposition for psychiatric disorder: comparison of subjects treated for cannabis-induced psychosis and schizophrenia
Arch. Gen. Psychiatry
(2008) - et al.
Differences between early-phase primary psychotic disorders with concurrent substance use and substance-induced psychoses
Arch. Gen. Psychiatry
(2005) - et al.
Stability of early-phase primary psychotic disorders with concurrent substance use and substance-induced psychosis
Br. J. Psychiatry
(2007) - et al.
First-episode drug-induced psychosis: a medium term follow up study reveals a high-risk group
Soc. Psychiatry Psychiatr. Epidemiol.
(2009)
Randomized controlled trial of a cannabis-focused intervention for young people with first-episode psychosis
Acta Psychiatr. Scand.
Psychotic disorders in urban areas: an overview of the study on low prevalence disorders
Aust. N. Z. J. Psychiatry
The Recognition and Management of Early Psychosis: a Preventive Approach
Cited by (22)
Premorbid characteristics of patients with DSM-IV psychotic disorders
2022, Comprehensive PsychiatryCitation Excerpt :To investigate this, however, more longitudinal studies are needed. It is also important to keep in mind that disorders classified as SIPD do not necessarily have a better outcome than PPDs [54,55]. Together with the current findings of poor premorbid adjustment in the PNOS-SIPD group, this has implications for their clinical management.
Substance-induced psychosis and cognitive functioning: A systematic review
2022, Psychiatry ResearchCitation Excerpt :There also appears to be a subset of individuals that are vulnerable to persistent symptoms (Voce et al., 2019), which challenges the current diagnostic scheme that makes a distinction between SIP and schizophrenia spectrum disorders. Indeed, clinical characteristics of first episode psychosis, including duration of untreated illness, symptom severity, time to remission, and rate of relapse are comparable between those with and without a substance-induced psychotic disorder (O'Connell et al., 2019). Cognitive impairment is also a core feature of psychotic disorders (McCleery and Nuechterlein, 2019) and a significant predictor of poor community and psychosocial functioning (Halverson et al., 2019).
The relationship between cannabis use and cognition in people diagnosed with first-episode psychosis
2020, Psychiatry ResearchCitation Excerpt :Some authors have argued that cannabis-induced psychotic disorders may in fact be an early sign of schizophrenia rather than a separate diagnostic entity (Arendt et al., 2008). In a large sample of people diagnosed with FEP, O'Connell et al. (2019) found people diagnosed with SIPD and those diagnosed with other FEP diagnoses to be clinically indistinct, notably with respect to psychotic symptom severity, remission and relapse rates, and vocational outcomes. The authors call into question the validity and utility of a specific diagnosis of SIPD and argue that substance use and symptoms of psychosis should be regarded as being associated with each other rather than one causing the other.
You say “schizophrenia” and I say “psychosis”: Just tell me when I can come off this medication
2020, Schizophrenia ResearchCitation Excerpt :Among those patients who received an initial diagnosis of substance-induced psychosis, 25% had a diagnosis of a primary psychotic disorder at 1-year follow-up. O'Connell et al. (O'Connell et al., 2019) reported on the follow-up of 56 patients with an initial diagnosis of substance-induced psychosis in Australia. After a mean follow-up of 84 weeks, 35.7% had a change of diagnosis to a schizophrenia spectrum disorder or bipolar disorder.
Substance-induced Psychosis in Youth
2020, Child and Adolescent Psychiatric Clinics of North AmericaCitation Excerpt :Although epidemiologic research is scarce, 1 study estimates the incidence of SIP to be approximately 6.5 in 100,000 persons per year, compared with 9.7 with PPD and comorbid substance misuse, and 24.1 with PPD alone.4 Among patients presenting to intervention services for first-episode psychosis (FEP), the proportion diagnosed with SIP as opposed to PPD or affective psychosis ranges between 6%5 and 10%.6 However, in studies examining an FEP cohort with past-month substance use, the prevalence of SIP increased dramatically, ranging from 44%7 to 56%.8