Swiss Archives of Neurology,
Psychiatry and Psychotherapy
Substance Use Disorder and Delusional Symptoms in Patients with Psychosis
Further Education Psychiatry and Psychotherapy
A Secondary Analysis from a Randomised Controlled Trial
Peer-review

Substance Use Disorder and Delusional Symptoms in Patients with Psychosis

Original Article
Further Education Psychiatry and Psychotherapy
Louise Penzenstadlera
Additional authors
Anne Chattona, Tania Lecomteb, Philippe Hugueleta,c, Laurent Lecardeurd, Javier Bartolomeia, Perrine Brazod,e, Elodie Murysf, Florent Poupartg,h, Daniele Zullinoa,c, Mohamed Saoudi, Jérôme Favrodk and Yasser Khazaall,m
Issue
2023/05
DOI:
https://doi.org/10.4414/sanp.2023.1264583089
Swiss Arch Neurol Psychiatr Psychother. 2023;174(05):150-155

Published on 18.10.2023

a Geneva University Hospitals, Geneva, Switzerland; b Department of Psychology, University of Montreal, Canada; c Faculty of Medicine, Geneva University, Geneva, Switzerland; d Normandie Université, UNICAEN, Imagerie et Stratégies Thérapeutiques de la Schizophrénie (ISTS), EA7466, Caen, France; e Normandie Université, UNICAEN, Centre Hospitalier Universitaire de Caen, Service de Psychiatrie d’adultes, Centre Esquirol, Caen, France; f Unité Mobile de Psychiatrie, Centre Hospitalier Princesse Grace, Monaco; g Laboratoire de Cliniques Pathologiques et Interculturelle (LCPI), Université de Toulouse, France; h Centre Hospitalier Universitaire de Toulouse, France; i PsyR², INSERM U1028, CNRS UMR5292, PSYR2 Team, Lyon Neuroscience Research Center, Université Claude Bernard Lyon 1, Department of Consultation-Liaison Psychiatry, Lyon, France; k La Source, School of Nursing, HES-SO University of Applied Sciences and Arts of Western Switzerland, Lausanne, Switzerland; l Addiction Medicine, Department of Psychiatry, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland; m Research Center, Institute of Mental Health, Montreal University, Montreal, Canada

Abstract

Background: Delusional thinking and low belief flexibility are important treatment targets in patients with psychotic disorders. Game-based interventions may improve hypothetical reasoning. As co-occurring substance use disorders (SUD) and psychotic disorders are common, the current study explores whether SUD may have an impact on the change of delusional beliefs in patients with psychosis.
Methods: This study is a secondary analysis of a longitudinal, assessor blinded, randomised controlled trial, in which 172 patients with positive psychosis symptoms were randomised into an intervention targeting belief flexibility. An improvement over time was found in the Peters et al. Delusion Inventory sub-scales and the Brief Psychiatric Rating Scale outcomes in the treatment group. The current study explores whether co-occurring SUD may have an impact on this change. We used a one-way repeated measures analysis of variance (ANOVA) with SUD present (yes vs no) as the between-subject factor and time as the within-subject factor. As 29% of the patients were not investigated for SUD, we also performed a sensitivity analysis in which we examined the undiagnosed participants as a fully-fledged group, allowing the analysis of all 172 participants.
Results: There was no significant effect of SUD. However, an overall significant time effect was observed for distress (F = 18.7, p <0.001), conviction (F = 19.8. p <0.001), preoccupation (F = 15.4, p <0.001) and BPRS (F = 6.3, p = 0.002). This means that all patients improved similarly on their reduction of all dimensions regardless of presenting an active SUD or not. The same analysis with a third group labelled “undiagnosed” almost replicated the above results.
Conclusions: The presence of concomitant SUD at baseline does not seem to influence treatment outcomes over time concerning delusional beliefs. Therefore, specialised programs for psychotic disorders can be as effective for patients with concurrent SUD as for patients with psychosis only.
Keywords: Psychosis; substance use disorders; delusional beliefs; peters delusion inventory; cognitive behaviour therapy; serious games

Background

Co-occurring substance use disorders (SUD) with severe mental illness are very common and have an important impact on treatment and outcomes. Patients with psychotic disorders are much more likely to suffer from SUD than the general population [1], with rates for lifetime SUD and psychotic disorder ranging from 20-60% [2, 3]. Concurrent SUD is more often associated with male gender, younger age, single marital status [4-6], conduct disorder and antisocial personality disorder [7, 8]. Even higher rates of SUD were reported amongst first episode psychosis patients [9-11]. Alcohol and cannabis are substances commonly consumed by dual diagnosed patients [12, 13], but the substances used with psychosis vary among patients [14]. Consuming multiple substances is common. Weaver et al. [13] found that 40% of patients with problematic drug use were also misusing alcohol. The consequences of SUD for patients with psychosis have been widely demonstrated. Substance use is linked to a more severe psychopathology [15, 16] with a higher positive [17–19] and negative symptom level [17, 20], greater interpersonal and family problems, as well as less self-efficacy [6] and a more severe course of the illness with a higher mortality rate [21]. Patients with dual diagnosis have been found to show lower rates of treatment compliance [22, 23]. Psychosocial instability, lower motivation levels and higher symptom levels, as well as higher perception of stigma, especially in patients with first-episode psychosis [24], may be barriers to accessing treatment. Patients with co-occurring disorders also find it more difficult to engage in traditional treatment plans [25]. A lack of services treating patients with dual diagnosis can, in part, explain the worse treatment outcomes. An assessment of services across the United States found that only 18% of addiction and 9% of mental health programs were offering integrated treatment [26]. While the importance of treating patients with psychosis and co-morbid SUD is clear, there is still need for the development of treatments and studies related to these concerns to improve the evidence in this domain [27]. However, some preliminary studies have found patients with mental disorders and co-occurring SUD to achieve clinical improvement similar to patients without SUD [28, 29]. Among others, cognitive behaviour therapy has been found effective as a conjunct treatment for psychosis [30–32].
Although some studies show lower overall functional outcomes linked to persisting SUD outcomes [16, 20], research on the impact of SUD on cognitive functioning and delusional thinking shows varying results [19, 33]. As mentioned above, more positive symptoms including delusions and hallucinations have been linked to SUD in first episode psychosis [18, 34, 35]. Delusional thinking impacts information processing and is often resistant to change despite treatment, making it an important measurement for treatment outcome [36-38]. The multidimensional concept of delusional beliefs can be divided into three components: distress, preoccupation and conviction of delusions [39]. These can be measured using Peters et al. Delusions Inventory (PDI-21) [40]. To our knowledge, no studies have specifically examined the impact of SUD on delusional thinking measured with the PDI-21.
In our analysis we would like to measure the impact of SUD on delusional thinking measured with the PDI-21 subscales. There is little literature examining the impact of SUD on these specific treatment outcomes compared to patients without SUD in programs for psychosis. As SUD has often been shown to negatively impact delusional thinking and to be linked to higher positive symptom levels in patients with psychosis, we hypothesised that there would be a difference in change over time for delusional thinking between SUD and No SUD participants.

Methods

The current study is part of a multicentre longitudinal randomised controlled trial (RCT) which explored the effectiveness of a cognitive restructuring intervention in 172 patients with psychotic disorders. Full detail of the RCT is given elsewhere [41]. Nevertheless, a short summary is outlined in the following paragraph to provide context.
The patients were recruited from psychiatric outpatient centres in Switzerland, France, Monaco and Italy. Inclusion criteria were: having a psychotic disorder according to DSM-IV, aged 18–65 years and persistent positive psychotic symptoms at inclusion. The exclusion criteria were: organic brain disease, mental retardation, prior participation in the game group, cognitive therapy of psychotic symptoms at inclusion and important disorganisation.
In the original study, half of the participants were randomly assigned to a novel cognitive game-based intervention targeting belief flexibility and the other half to a standard treatment. The intervention consisted of a collaborative group game with 1-hour weekly sessions. It used 80 cards presenting different situations to train ability to reason with hypotheses. Pharmacological treatment for psychosis and psychosocial care were offered to all of them. Primary and secondary outcomes were measured before the intervention (T1), three months after the intervention (T2) and again six months later (T3) in a repeated ANOVA design. The conviction subscale of the PDI-21, taken as the main outcome measure, showed an improvement in delusional thinking over time in the intervention group. The protocol of the original study was approved by institutional review boards and the Ethics Committees in Switzerland (Geneva), France and Italy. It is registered under the reference ISRCTN37178153.
Given that the possible effect of SUD was not assessed in the main study, the current report filled this gap by investigating in secondary analysis [35] whether this comorbidity might have an impact on the above-cited findings. Therefore, we conducted a repeated one-way between-groups ANOVA to explore the effect of SUD on PDI-21 subscale scores and Brief Psychiatric Rating Scale total score [42]. The Mini International Neuropsychiatric Interview [43] served to identify patients with SUD.

Measures

Mini International Neuropsychiatric Interview (MINI) [43]

The MINI, a standardised interview, was developed to identify psychiatric disorders according to the DSM-IV. The validated French form was used [44]. The MINI, which was validated within the general population, has good validity, reliability, sensitivity and specificity indices [44, 45]. Patients were investigated with the MINI questionnaire for their actual alcohol use and other illegal substances, ending up with an abuse or dependence diagnosis. Following the assessment, of the initial 172 participants, 122 were formally diagnosed with or without SUD and 50 could not be diagnosed for lack of information, leaving a sample of 122 with complete data for analysis. Of these, seven patients presented alcohol abuse and four a dependency. Nine patients presented abuse of another psychoactive substance and ten a dependency. Due to the small number of patients presenting a SUD, we regrouped patients with abuse and dependency.
In total, 14.8% (N=18) were diagnosed as having a SUD in the same year while 85.2% (N=104) did not present a concomitant SUD.

Peters et al. Delusions Inventory (PDI) [39, 40]

The PDI was developed for use in the general population [39]. It consists of three dimensions (distress, preoccupation and conviction). A five-point Likert scale is used to measure 21 stated beliefs [40]. This questionnaire has shown good internal consistency, test-retest agreement and good concurrent validity pertaining to delusional ideation [46], magical ideation [47] and schizotypal measures [48]. Patients with psychotic disorders were found to have higher ratings on these scales compared to controls [39]. We used the French validated form of the scale [49].

Brief Psychiatric Rating Scale (BPRS) [42]

The BPRS measures psychiatric symptom levels. It uses a seven-point Likert scale from zero (not present) to six (extremely present) to measure 18 symptom constructs. The BPRS has shown good reliability and validity [50].

Statistical Analyses

Preliminary descriptive statistics, such as mean and standard deviation (SD) or percentages, were reported for demographic and clinical characteristics. Group comparisons were made using t-tests for continuous variables (or Mann-Whitney U test when required) and chi-square tests of homogeneity for categorical variables. To analyse the evolution of PDI subscores and BPRS total scores, we used a one-way repeated measures ANOVA first on a complete-case analysis basis with SUD membership (yes vs no) as the between-subject factor and time as the within-subject factor. Second, as missingness represents a non-negligible part of the study sample (29%), we performed a sensitivity analysis in which we analysed the undiagnosed participants as a fully-fledged group allowing the analysis of all 172 participants. The SUD variable then takes three categories: yes vs no vs undiagnosed. One-way repeated ANOVA design allows to separate out the effects of group and time and, more importantly, allows to analyse group-by-time interaction effects. To adjust for multiple testing with four outcomes measures considered, statistical significance was set at p≤0.0125. The statistical analyses were performed with SPSS software [51].

Results

The mean age of participants in the sample was around 37 years (SD=10.8). 22% of participants had attained a high school diploma or a university degree. The majority of the participants had a diagnosis of schizophrenia (84.4%), were single (80.3%) and more than half lived in a private residence (58.2%).
Except for age and living conditions, there were no statistical differences in the socio-demographic measures between patients with and without SUD. Patients with SUD were younger and more likely lived in residential places than those without SUD (p=0.03 and p=0.04 respectively). There was no other significant difference between the groups at baseline. See table 1 for further demographic and clinical characteristics.
Results of the repeated ANOVA showed no significant SUD effect on PDI distress, neither significant group-by-time interaction effect. However, an overall significant time effect was observed (F=18.7, p<0.001), meaning that a change over time in this outcome occurred for the total sample, independently of group membership. The tests of within-subjects contrasts showed that there were significant differences between T1 and T2 (p=0.01) and between T2 and T3 (p<0.001) (see table 2 and fig. 1).
Figure 1: Evolution ot PDI Distress over time. PDI: Peters et al. Delusions Inventory; CI: Confidence interval.
Similarly, an overall significant time effect was observed for PDI conviction (F=19.8, p<0.001) but no group effect. The test of within-subjects contrasts showed significant differences between T1 and T2 (p=0.002) and T2 and T3 (p<0.001) (see table 2 and fig. 2).
Figure 2: Evolution of PDI Conviction over time. PDI: Peters et al. Delusions Inventory; CI: Confidence interval.
The evolution of PDI preoccupation scores followed the same pattern as that observed for distress and conviction with one minor variation: the difference was not significant between T1 and T2 (p=0.05) taking account of the Bonferroni correction for multiple testing. As for the evolution between T2 and T3 the difference was highly significant (p<0.001) (see table 2 and fig. 3).
Figure 3: Evolution of PDI Preoccupation over time. PDI: Peters et al. Delusions Inventory; CI: Confidence interval.
As for BPRS, a significant overall time effect was observed (F=6.3, p=0.002). The test of within-subjects contrasts showed that this significant difference laid between T1 and T2 only (F=8.0, p=0.006). No other effect was detected (see table 2 and fig. 4).
Figure 4: Evolution of BPRS over time. BPRS: Brief Psychiatric Rating Scale; CI: Confidence interval.
The same analyses were repeated with the missing participants as a 3rd “undiagnosed” group (detailed results not shown). There was an improvement over the complete case analysis results for the PDI subscales where all time effects were significant, including preoccupation, now being significant between T1 and T2 (p=0.002). The results for BPRS remained unchanged compared to the complete case analysis.

Discussion

The PDI distress, conviction and preoccupation subscores decreased over time. However, when analysing the interaction effect of group by time, the result was not statistically significant. This contradicts our hypothesis that SUD would influence the change over time in the PDI scores, implying that all patients improved similarly concerning a reduction in the three dimensions of delusional beliefs, regardless of presenting an active SUD or not. Lack of power might explain the finding as there were only a few patients with SUD in the sample. Another reason might also be that the usual pharmacological and psychosocial treatment received by all patients was equally effective, whether diagnosed with SUD or not.
The overall time effect observed in psychiatric symptom levels according to the BPRS was captured between T1 and T2 only. Nevertheless, these improvements regardless of SUD are important findings as this shows that specialised interventions are effective, despite SUD. It is interesting to note that this study sample of patients with SUD did not have a higher symptom level than patients without SUD (see table 1). This is interesting, as in literature SUD is often shown to be linked to higher symptom levels [17, 19]. However, the fact that the patients presenting SUD were twice as often housed in residential accommodations and on average younger, implies an overall lower psychosocial functioning, in concordance with other observations [52].
Other studies have found persistent substance use in patients with psychosis and concurrent SUD to be linked to less improvement on general outcome measures, such as functional outcomes, higher illness severity, more positive symptoms, higher service use, non‐compliance, treatment drop‐out and poor remission rates [2, 18, 20, 52, 53]. Low social functioning, financial problems and younger age in patients with schizophrenia have also been linked to treatment drop-out [54].
It is possible, that the more intensive treatment in the game-format group sessions may have improved their outcomes despite the SUD. The use of serious games has also been shown to improve treatment drop-out, which is generally higher in patients with co-occurring SUD [53, 55]. Such observations on social outcomes stress the needs to offer other comprehensive treatments targeting the social inclusion needs in addition to specific treatments, like the ones focusing on hypothetical hypothesis training [56, 57].
Certain studies specifically focused on integrating SUD treatment into their programs and measured the outcomes relative to substance use. Barrowclough et al. applied motivational interviewing, which was used as a complement to the usual treatment in their RCT [58]. Another RCT in a hospital setting integrated a SUD-specific group therapy to standard treatment [59]. Both studies found increased abstinence motivation and reduced substance use. The Canadian Schizophrenia Guidelines [60] and the NICE guidelines [61] recommend combined use of antipsychotic medication and psychosocial interventions for addictions. This has been confirmed by several studies which have suggested integrated treatment using antipsychotic medication as well as psychosocial interventions, cognitive behavioural therapy (CBT) and motivational interviewing for patients with dual diagnosis [58, 59]. Overall evidence suggests offering integrated motivational treatment with low threshold entry levels to improve treatment access for this vulnerable group of patients. Furthermore, studies examining treatments focusing on specific psychiatric symptoms have found these equally effective in improving psychiatric outcomes and can improve treatment engagement in individuals with and without SUD [22, 62]. Patients presenting concurrent SUD are sometimes treated in addiction programs rather than specialised psychiatric services for psychosis. Our findings imply, that these patients can equally benefit from treatment programs for psychosis. As a result, screening patients for co-occurring disorders is important in all psychiatric and addiction settings. Treatment programs for psychosis should be systematically offered to patients with co-occurring SUD, as they may improve long-term outcomes and functioning [28]. Equally, patients with coexisting disorders may also benefit from addiction programs. It is necessary to offer specific treatment options for both disorders as well as further develop specialised integrated programs. Unspecific factors, such as therapeutic alliance, are certain to play a role. Patients with SUD might specifically benefit from the attention given to them in intensive treatment programs. This could have influenced outcome measures. Studies have shown that substance use reduced up to 50% when patients were in treatment programs for psychosis [2, 20].
The group treatment offered to the participants of the study consisted of a serious game using CBT tools to improve patients’ ability to find alternative hypothesis for different situations [41]. The game was well accepted by the participants [63]. Game-based approaches have been found to improve problem solving and increase treatment adherence when treating patients with psychosis. The findings of this study encourage the development of game-based treatments for co-occurring SUD and psychosis. Furthermore, CBT has been widely used for SUD [64, 65] and is being implemented more frequently for patients with psychosis [30, 31, 66, 67]. One study examined a CBT intervention for patients with psychosis and cannabis use [68]. The study showed greater reduction in cannabis use and positive symptoms, as well as improved functioning in the CBT group. These findings highlight the importance of improving access to CBT for patients with psychosis and co-occurring SUD as well as developing specific CBT interventions for these patients [69].
A particular strength of this study is, that the influence of SUD measured was an active SUD during the same year and therefore during or close to the treatment period. Also, the multicentre design allowed a better generalisability of the results even though the sample size was small. To confirm efficacy and long-term outcome, further studies with larger samples are needed. It will be important for future studies to include patients with and without SUD. Also, measuring outcomes on substance use will allow us to further test the hypothesis that specific treatment for psychosis is also effective for patients with coexisting SUD.
There were some limitations in this study. We did not have any information available on the duration of disease or treatment, nor on the number and duration of hospitalisations. This would have also played an important role in influencing insight and therefore delusional belief. The data collected did not differentiate between different psychotic disorders, which may have influenced the outcome. However, the majority (around 80% in both groups) of patients were diagnosed with schizophrenia. The number of patients was particularly limited for the SUD group. It is possible that the presence of SUD was undervalued for some patients. This could be explained by two factors. First, patients were recruited in psychiatric facilities, while part of patients with SUD and comorbid psychotic disorders received their treatments in services for addictive disorders. Second, we systematically assessed current SUD and not lifetime SUD which probably contributes to lower figures. We do not have information on the severity of SUD as this was a secondary analysis and the presence of SUD was examined later using the information from the MINI. The diagnosis of SUD at study entry did not exclude a possible SUD in the patients’ history. As the patients chose to participate in the group intervention and study, it limits the possible number of patients with severe SUD. Patients with more severe disorders are known to have more difficulties accessing treatment [70, 71]. They are also more likely to be enrolled in addiction programs rather than specialised psychiatric treatment programs. As the information was not available, we did not control the effects for opioid substitution or other SUD treatments. As SUD was not part of the original research question, substance use was only investigated at the beginning of the program and not in the follow-up exams. We therefore have no further information about the change of specific substance use habits in the course of treatment. It is therefore not possible to describe changes in SUD related behaviours during treatment. It is however possible, that the treatment offered might also improve outcomes for SUD even though these are not specifically targeted and should be assessed in further studies. In this sample, the symptom levels did not differ significantly between SUD and No SUD patients at baseline. This might be a reason that, in our sample, SUD did not impact treatment outcomes. Further studies on larger samples would be helpful to confirm these findings. And even though we have follow-up measures at nine months we do not have long-term outcomes to show if these are of lasting nature.

Conclusions

The presence of SUD at baseline does not seem to influence treatment outcomes over time concerning the three dimensions of delusional beliefs as measured by PDI-21. Therefore, specialised programs for psychotic disorders can be as effective for patients with concurrent SUD as for patients with psychosis only. Such treatments should be offered to patients with these comorbid disorders. It could help enhance outcomes in both areas treating the two disorders simultaneously. With one exception, the results of the sensitivity analyses matched those of the complete case analyses.

List of Abbreviations

  • BPRS Brief Psychiatric Rating Scale
  • MINI Mini International Neuropsychiatric Interview
  • PDI Peters et al. Delusions Inventory
  • SD Standard deviation
  • SUD Substance use disorders
Dr. Louise Penzenstadler Geneva University Hospitals, Geneva, Switzerland
No financial support and no other potential conflict of interest relevant to this article was reported.
Yasser Khazaal and Jérôme Favrod are authors of the game. The research was conducted in the absence of any commercial or financial relationship that could be conceived as a potential conflict of interest.
L.P. and Y.K. contributed to the conception and design of the secondary analysis. The formal analysis was performed by A.C. The first draft of the manuscript was written by L.P., T.L. and Y.K. and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.
Data can be made available by the corresponding author upon request.
Dr. Louise Penzenstadler
Geneva University Hospitals
Rue de Grand-Pré, 70 C
CH-1202 Geneva
Phone: +41 22 3725750
Fax: +41 22 3725754
Louise.E.Penzenstadler[at]hcuge.ch
The Ethical Committees in the respective countries approved the original study. The protocol was registered (International Standard Randomized Controlled Trial Number Register: ISRCTN37178153).
All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2000 [5]. Informed consent was obtained from all patients included in the study.
1 Regier D, Farmer M, Rae D, Locke B, Keith S, Judd L, et al. Comorbidity of mental disorders with alcohol and other drug abuse: results from the Epidemiologic Catchment Area (ECA) study. Jama. 1990;264(19):2511–8.
2 Lambert M, Conus P, Lubman DI, Wade D, Yuen H, Moritz S, et al. The impact of substance use disorders on clinical outcome in 643 patients with first-episode psychosis. Acta Psychiatr Scand. 2005 Aug;112(2):141–8.
3 Hunt GE, Large MM, Cleary M, Lai HMX, Saunders JB. Prevalence of comorbid substance use in schizophrenia spectrum disorders in community and clinical settings, 1990–2017: Systematic review and meta-analysis. Drug Alcohol Depend. 2018 Oct 1;191:234–58.
4 Cantor-Graae E, Nordström LG, McNeil TF. Substance abuse in schizophrenia: a review of the literature and a study of correlates in Sweden. Schizophr Res. 2001 Mar;48(1):69–82.
5 Duke PJ, Pantelis C, McPhillips MA, Barnes TRE. Comorbid non-alcohol substance misuse among people with schizophrenia: Epidemiological study in central London. Br J Psychiatry. 2001 Dec;179(6):509–13.
6 Salyers MP, Mueser KT. Social functioning, psychopathology, and medication side effects in relation to substance use and abuse in schizophrenia. Schizophr Res. 2001 Mar;48(1):109–23.
7 Mueser KT, Drake RE, Ackerson TH, Alterman AI, Miles KM, Noordsy DL. Antisocial personality disorder, conduct disorder, and substance abuse in schizophrenia. J Abnorm Psychol. 1997;106(3):473–7.
8 Mueser KT, Rosenberg SD, Drake RE, Miles KM, Wolford G, Vidaver R, et al. Conduct disorder, antisocial personality disorder and substance use disorders in schizophrenia and major affective disorders. J Stud Alcohol. 1999 Mar;60(2):278–84.
9 Sevy S, Robinson DG, Holloway S, Alvir JM, Woerner MG, Bilder R, et al. Correlates of substance misuse in patients with first-episode schizophrenia and schizoaffective disorder: Substance misuse in schizophrenia. Acta Psychiatr Scand. 2008 Jul 18;104(5):367–74.
10 Kavanagh DJ, Waghorn G, Jenner L, Chant DC, Carr V, Evans M, et al. Demographic and clinical correlates of comorbid substance use disorders in psychosis: multivariate analyses from an epidemiological sample. Schizophr Res. 2004 Feb;66(2–3):115–24.
11 Green AI, Tohen MF, Hamer RM, Strakowski SM, Lieberman JA, Glick I, et al. First episode schizophrenia-related psychosis and substance use disorders: acute response to olanzapine and haloperidol. Schizophr Res. 2004 Feb;66(2–3):125–35.
12 Kessler RC, Nelson CB, McGonagle KA, Edlund MJ, Frank RG, Leaf PJ. The epidemiology of co-occurring addictive and mental disorders: Implications for prevention and service utilization. Am J Orthopsychiatry. 1996;66(1):17–31.
13 Weaver T, Madden P, Charles V, Stimson G, Renton A, Tyrer P, et al. Comorbidity of substance misuse and mental illness in community mental health and substance misuse services. Br J Psychiatry. 2003 Oct;183(4):304–13.
14 Gregg L, Barrowclough C, Haddock G. Reasons for increased substance use in psychosis. Clin Psychol Rev. 2007 May;27(4):494–510.
15 Faridi K, Joober R, Malla A. Medication adherence mediates the impact of sustained cannabis use on symptom levels in first-episode psychosis. Schizophr Res. 2012 Oct;141(1):78–82.
16 Farrelly S, Harris MG, Henry LP, Purcell R, Prosser A, Schwartz O, et al. Prevalence and correlates of comorbidity 8 years after a first psychotic episode. Acta Psychiatr Scand. 2007 Jul;116(1):62–70.
17 Bennett ME, Bellack AS, Brown CH, DiClemente C. Substance dependence and remission in schizophrenia: A comparison of schizophrenia and affective disorders. Addict Behav. 2009;34(10):806–14.
18 Harrison I, Joyce EM, Mutsatsa SH, Hutton SB, Huddy V, Kapasi M, et al. Naturalistic follow-up of co-morbid substance use in schizophrenia: the West London first-episode study. Psychol Med. 2008 Jan;38(1):79–88.
19 Pencer A, Addington J. Substance use and cognition in early psychosis. J Psychiatry Neurosci JPN. 2003 Jan;28(1):48–54.
20 Abdel-Baki A, Ouellet-Plamondon C, Salvat É, Grar K, Potvin S. Symptomatic and functional outcomes of substance use disorder persistence 2 years after admission to a first-episode psychosis program. Psychiatry Res. 2017 Jan;247:113–9.
21 Schmidt LM, Hesse M, Lykke J. The impact of substance use disorders on the course of schizophrenia  A 15-year follow-up study. Schizophr Res. 2011 Aug;130(1–3):228–33.
22 Brabban A, Tai S, Turkington D. Predictors of Outcome in Brief Cognitive Behavior Therapy for Schizophrenia. Schizophr Bull. 2009 Sep 1;35(5):859–64.
23 Janssen B, Gaebel W, Haerter M, Komaharadi F, Lindel B, Weinmann S. Evaluation of factors influencing medication compliance in inpatient treatment of psychotic disorders. Psychopharmacology (Berl). 2006 Aug;187(2):229–36.
24 Brunette MF, Mueser KT, Babbin S, Meyer-Kalos P, Rosenheck R, Correll CU, et al. Demographic and clinical correlates of substance use disorders in first episode psychosis. Schizophr Res. 2018;194:4–12.
25 Drake RE, Mueser KT, Brunette MF, McHugo GJ. A Review of Treatments for People with Severe Mental Illnesses and Co-Occurring Substance Use Disorders. Psychiatr Rehabil J. 2004;27(4):360–74.
26 McGovern MP, Lambert-Harris C, Gotham HJ, Claus RE, Xie H. Dual Diagnosis Capability in Mental Health and Addiction Treatment Services: An Assessment of Programs Across Multiple State Systems. Adm Policy Ment Health Ment Health Serv Res. 2014 Mar;41(2):205–14.
27 Hunt GE, Siegfried N, Morley K, Brooke-Sumner C, Cleary M. Psychosocial interventions for people with both severe mental illness and substance misuse. Cochrane Database Syst Rev. 2019 Dec 12;12:CD001088.
28 Florentin S, Rosca P, Bdolah-Abram T, Neumark Y. Community Rehabilitation and Hospitalizations Among People With Chronic Psychotic Disorder: Is There a Differential Association by Co-occurring Substance Use Disorder? Front Psychiatry [Internet]. 2021 [cited 2022 Aug 1];12. Available from: https://www.frontiersin.org/articles/10.3389/fpsyt.2021.621259
29 Penzenstadler L, Kolly S, Rothen S, Khazaal Y, Kramer U. Effects of substance use disorder on treatment process and outcome in a ten-session psychiatric treatment for borderline personality disorder. Subst Abuse Treat Prev Policy. 2018 26;13(1):10.
30 Ryan M, Sattenspiel D, Chianese A, Rice H. CE: Original Research: Cognitive Behavioral Therapy for Symptom Management in Treatment-Resistant Schizophrenia. Am J Nurs. 2022 Aug 1;122(8):24–33.
31 Shukla P, Padhi D, Sengar KS, Singh A, Chaudhury S. Efficacy and durability of cognitive behavior therapy in managing hallucination in patients with schizophrenia. Ind Psychiatry J. 2021 Dec;30(2):255–64.
32 Phelan S, Sigala N. The effect of treatment on insight in psychotic disorders - A systematic review and meta-analysis. Schizophr Res. 2022 Jun;244:126–33.
33 McCleery A, Addington J, Addington D. Substance misuse and cognitive functioning in early psychosis: a 2 year follow-up. Schizophr Res. 2006 Dec;88(1–3):187–91.
34 Bühler B, Hambrecht M, Löffler W, an der Heiden W, Häfner H. Precipitation and determination of the onset and course of schizophrenia by substance abuse--a retrospective and prospective study of 232 population-based first illness episodes. Schizophr Res. 2002 Apr 1;54(3):243–51.
35 Grech A, Van Os J, Jones PB, Lewis SW, Murray RM. Cannabis use and outcome of recent onset psychosis. Eur Psychiatry J Assoc Eur Psychiatr. 2005 Jun;20(4):349–53.
36 Mizrahi R, Kiang M, Mamo DC, Arenovich T, Bagby RM, Zipursky RB, et al. The selective effect of antipsychotics on the different dimensions of the experience of psychosis in schizophrenia spectrum disorders. Schizophr Res. 2006 Dec 1;88(1):111–8.
37 Moritz S, Kerstan A, Veckenstedt R, Randjbar S, Vitzthum F, Schmidt C, et al. Further evidence for the efficacy of a metacognitive group training in schizophrenia. Behav Res Ther. 2011 Mar 1;49(3):151–7.
38 Waller H, Freeman D, Jolley S, Dunn G, Garety P. Targeting reasoning biases in delusions: A pilot study of the Maudsley Review Training Programme for individuals with persistent, high conviction delusions. J Behav Ther Exp Psychiatry. 2011 Sep 1;42(3):414–21.
39 Peters ER, Joseph SA, Garety PA. Measurement of delusional ideation in the normal population: introducing the PDI (Peters et al. Delusions Inventory). Schizophr Bull. 1999;25(3):553–76.
40 Peters E, Joseph S, Day S, Garety P. Measuring Delusional Ideation: The 21-Item Peters et al. Delusions Inventory (PDI). Schizophr Bull. 2004 Jan 1;30(4):1005–22.
41 Khazaal Y, Chatton A, Dieben K, Huguelet P, Boucherie M, Monney G, et al. Reducing Delusional Conviction through a Cognitive-Based Group Training Game: A Multicentre Randomized Controlled Trial. Front Psychiatry [Internet]. 2015 Apr 28 [cited 2019 Apr 24];6. Available from: http://journal.frontiersin.org/article/10.3389/fpsyt.2015.00066/abstract
42 Overall J, Gorham D. The brief psychiatric rating scale. Psychol Rep. 1962;10(3):799–812.
43 Sheehan DV, Lecrubier Y, Sheehan KH, Amorim P, Janavs J, Weiller E, et al. The Mini-International Neuropsychiatric Interview (M.I.N.I.): the development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10. J Clin Psychiatry. 1998;59 Suppl 20:22-33;quiz 34-57.
44 Lecrubier Y, Sheehan D, Weiller E, Amorim P, Bonora I, Harnett Sheehan K, et al. The Mini International Neuropsychiatric Interview (MINI). A short diagnostic structured interview: reliability and validity according to the CIDI. Eur Psychiatry. 1997;12(5):224–31.
45 Sheehan D, Lecrubier Y, Harnett Sheehan K, Janavs J, Weiller E, Keskiner A, et al. The validity of the Mini International Neuropsychiatric Interview (MINI) according to the SCID-P and its reliability. Eur Psychiatry. 1997;12(5):232–41.
46 Foulds GA, Bedford A. Hierarchy of classes of personal illness. Psychol Med. 1975 May;5(2):181–92.
47 Eckblad M, Chapman LJ. Development and validation of a scale for hypomanic personality. J Abnorm Psychol. 1986 Aug;95(3):214–22.
48 Claridge G, McCreery C, Mason O, Bentall R, Boyle G, Slade P, et al. The factor structure of "schizotypal’ traits: a large replication study. Br J Clin Psychol. 1996;35(1):103–15.
49 Verdoux H, van Os J. Psychotic symptoms in non-clinical populations and the continuum of psychosis. Schizophr Res. 2002 Mar;54(1–2):59–65.
50 Hedlund J, Vieweg B. The brief psychiatric rating scale (BPRS):A comprehensive review. J Oper Psychiatry. 1980;11:48–64.
51 IBMCorp Ibm SPSS. statistics for windows, version 25.0. Armonk, NY:IBM Corp; 2017.
52 Ruppelt F, Rohenkohl A, Kraft V, Schöttle D, Schröter R, Gaianigo J, et al. Course, remission and recovery in patients with severe psychotic disorders with or without comorbid substance use disorders: long-term outcome in evidence-based integrated care (ACCESS II study). Schizophr Res. 2020;222:437–43.
53 Bouchard M, Lecomte T, Cloutier B, Herrera-Roberge J, Potvin S. Dropout Rates in Psychosocial Interventions for People With Both Severe Mental Illness and Substance Misuse: A Systematic Review and Meta-Analysis. Front Psychiatry. 2022;13:842329.
54 Kreyenbuhl J, Nossel IR, Dixon LB. Disengagement from mental health treatment among individuals with schizophrenia and strategies for facilitating connections to care: a review of the literature. Schizophr Bull. 2009 Jul;35(4):696–703.
55 Jankowski S, Ferreira K, Mascayano F, Donovan E, Rahim R, Birnbaum ML, et al. A Serious Game for Young People With First Episode Psychosis (OnTrack>The Game): Qualitative Findings of a Randomized Controlled Trial. JMIR Ment Health. 2022 Apr 6;9(4):e33526.
56 Pilarinos A, Fast D, Nosova E, Kwa Y, Joe R, Buxton JA, et al. Initiation of opioid agonist treatment and subsequent substance use and other patterns among adolescents and young adults in Vancouver, Canada. Drug Alcohol Depend. 2022;235:109441.
57 Penzenstadler L, Soares C, Anci E, Molodynski A, Khazaal Y. Effect of Assertive Community Treatment for Patients with Substance Use Disorder: A Systematic Review. Eur Addict Res. 2019;25(2):56–67.
58 Barrowclough C, Haddock G, Wykes T, Beardmore R, Conrod P, Craig T, et al. Integrated motivational interviewing and cognitive behavioural therapy for people with psychosis and comorbid substance misuse: randomised controlled trial. BMJ. 2010;341:c6325.
59 Gouzoulis-Mayfrank E, König S, Koebke S, Schnell T, Schmitz-Buhl M, Daumann J. Trans-Sector Integrated Treatment in Psychosis and Addiction. Dtsch Aerzteblatt Online [Internet]. 2015 Oct 9 [cited 2019 May 18]; Available from: https://www.aerzteblatt.de/10.3238/arztebl.2015.0683
60 Crockford D, Addington D. Canadian schizophrenia guidelines: schizophrenia and other psychotic disorders with coexisting substance use disorders. Can J Psychiatry. 2017;62(9):624–34.
61 National Collaborating Centre for Mental Health. Coexisting severe mental illness (psychosis) and substance misuse: assessment and management in healthcare settings. Clinical guideline 120. Natl Inst Health Care Excell [Internet]. 2011; Available from: http://guidance.nice.org.uk/CG120
62 Urbanoski K, Veldhuizen S, Krausz M, Schutz C, Somers JM, Kirst M, et al. Effects of comorbid substance use disorders on outcomes in a Housing First intervention for homeless people with mental illness: Effectiveness of Housing First. Addiction. 2018 Jan;113(1):137–45.
63 Khazaal Y, Favrod J, Azoulay S, Finot SC, Bernabotto M, Raffard S, et al. “Michael’s Game,” a card game for the treatment of psychotic symptoms. Patient Educ Couns. 2011 May;83(2):210–6.
64 Ray LA, Meredith LR, Kiluk BD, Walthers J, Carroll KM, Magill M. Combined Pharmacotherapy and Cognitive Behavioral Therapy for Adults With Alcohol or Substance Use Disorders: A Systematic Review and Meta-analysis. JAMA Netw Open. 2020 Jun 1;3(6):e208279.
65 Roos CR, Carroll KM, Nich C, Frankforter T, Kiluk BD. Short- and long-term changes in substance-related coping as mediators of in-person and computerized CBT for alcohol and drug use disorders. Drug Alcohol Depend. 2020 Jul 1;212:108044.
66 Guaiana G, Abbatecola M, Aali G, Tarantino F, Ebuenyi ID, Lucarini V, et al. Cognitive behavioural therapy (group) for schizophrenia. Cochrane Database Syst Rev. 2022 Jul 12;7:CD009608.
67 Carruthers SP, Van Rheenen TE, Karantonis JA, Rossell SL. Characterising Demographic, Clinical and Functional Features of Cognitive Subgroups in Schizophrenia Spectrum Disorders: A Systematic Review. Neuropsychol Rev. Epub 2021 Oct 25. PMID: 34694542.
68 González-Ortega I, Echeburúa E, Alberich S, Bernardo M, Vieta E, de Pablo GS, et al. Cognitive Behavioral Therapy Program for Cannabis Use Cessation in First-Episode Psychosis Patients: A 1-Year Randomized Controlled Trial. Int J Environ Res Public Health. 2022 Jun 15;19(12):7325.
69 Grossman MJ, Doell FK, Watson-Gaze J, Baer LH, Martins F, Kidd SA. Increasing Access to CBT for Psychosis: Development, Feasibility, and Acceptability of a Specialized Outpatient Service. Community Ment Health J. 2022 Mar 17. PMID: 35301615
70 Marchand K, Beaumont S, Westfall J, MacDonald S, Harrison S, Marsh DC, et al. Conceptualizing patient-centered care for substance use disorder treatment: findings from a systematic scoping review. Subst Abuse Treat Prev Policy. 2019 Sep 11;14(1):37.
71 Mojtabai R, Chen LY, Kaufmann CN, Crum RM. Comparing barriers to mental health treatment and substance use disorder treatment among individuals with comorbid major depression and substance use disorders. J Subst Abuse Treat. 2014 Feb;46(2):268–73.
The original study, which provided data for this analysis, was supported by the Swiss National Science Foundation [grant number 32003B-121038].

Published under the copyright license.

"Attribution - Non-Commercial - NoDerivatives 4.0"

No commercial reuse without permission.

See: emh.ch/en/emh/rights-and-licences/

 

 

KERKPUN
To the top