Strategies for Treatment Enhancement and Psychosis-understanding in Substance Induced Psychosis - STEP-SIP

Substance-induced psychosis (SIP) is a transient psychotic episode in close temporal relation to substance use, diagnostically classified as a substance use disorder (ICD-10 F1x.5). This classification creates a critical treatment and research gap. SIP patients present with severe psychotic symptoms but often fall between two distinct service areas: substance use disorder (SUD) treatment and specialist psychosis treatment. Annually there are approximately 500 incident cases of SIP in Norway, and we know from our own and international research that one in four later are diagnosed with a schizophrenia spectrum disorder. There is a need for a better understanding of the phenomenon SIP. We know that these patients are repeatedly admitted to acute wards, but we do not know the number and length of the hospitalizations and how this differs between the different substance-specific types of SIP. We do not know how many of incident cases of schizophrenia who come from SIP and SUD, and if the duration of time before you receive an F2 diagnosis differ between those who are initially diagnosed SIP versus other diagnostic codes (e.g. “other non-specified psychosis”, F29). Finally, we need sufficiently large clinical studies to describe the clinical manifestations and to determine whether symptoms and other characteristics can meaningfully differentiate SIP from acute schizophrenia with comorbid SUD. The aims of the study are as follows: I): to investigate the treatment utilization pattern for any SIP, different types of SIP and the transition to schizophrenia. - What is the number and length of hospitalizations, for any SIP and for the different substance-specific types of SIP for the whole period? - Among those who transition from SIP to schizophrenia, does the time and frequency of hospitalizations differ for the substance-specific SIPs? - Are there geographical and temporal variation in alternative diagnostic practices (F1x.0 (drug intoxication) vs. SIP vs. F29 (unspecified psychosis) + SUD)? II): to investigate the proportion of incident cases of schizophrenia who previously have been diagnosed with SIP and other relevant diagnoses. - How many of the incident cases of schizophrenia come from: SIP; F1x.2 (substance dependency); F1x.0 (intoxication); F29+ SUD;other F2-diagnosis, any other diagnosis; no diagnosis? - Does the time from first contact with a specific diagnostic category (specified in RQ 4) to incident schizophrenia vary according to the type of first diagnosis? III): to investigate clinical characteristics for patients with SIP compared to patients with either an F2 diagnoses with comorbid SUD, or a F2 diagnoses without comorbid SUD. - What are the clinical characteristics in the acute phase for patients with SIP compared to patients with a) F2 diagnosis with comorbid SUD, and b) F2 diagnoses without comorbid SUD, with regard to psychotic symptoms, risk of violence, medication, and number of forced interventions? The STEP-SIP project has two primary sources of data: the National patient registry (NPR) and the quality- and research register at the Mental Health and Addiction (PHA-reg) at Oslo University Hospital.