Substance use, medication adherence and outcome one year following a first episode of psychosis

Abstract

Substance use, medication adherence and outcome one year following a first episode of psychosis ABSTRACT Both substance use and poor medication adherence are associated with poor outcome in psychosis. To clarify the contributions of substance use and poor medication adherence to poor outcome in the year following a first episode of psychosis, 205 patients were evaluated for use of tobacco, alcohol, cannabis and stimulants at their psychosis onset, and in a 1-year follow-up. Data on medication adherence and symptom remission were also collected. Patients had high rates of overall substance use before (37-65%) and after psychosis onset (45-66%). 44% showed poor medication adherence and 55% did not reach remission from psychosis. Nicotine dependence and cannabis use after psychosis onset significantly predicted both poor medication adherence and nonremission, and poor medication adherence mediated the effects of these substances on nonremission. In conclusion, medication adherence lies on the causal pathway between nicotine dependence and cannabis on the one hand and non-remission on the other.

Real-world adherence and economic outcomes associated with paliperidone palmitate versus oral atypical antipsychotics in schizophrenia patients with substance-related disorders using Medicaid benefits

“…3 MPR was defined as the sum of the days of supply of medication dispensed divided by the number of days between the first fill and the last refill plus the days of supply of the last refill. 4 Persistence was defined as not having any gap more than 30, 60 or 90 days between the days of supply of medication refills. MPR: Medication possession ratio; OAA: Oral atypical antipsychotics; PDC: Proportion of days covered; PP1M: Once-monthly paliperidone palmitate; SD: Standard deviation.…”

“…While efficacy may be similar for patients with and without co-occurring substance-related disorders, when differences in treatment duration have been taken into account, substance use consistently predicts poorer adherence and higher rates of discontinuation [4][5][6]. In a recent pooled analysis of two randomized trials (total n = 1154), substance use was associated with reduced adherence which sequentially predicted earlier discontinuation [23].…”

“…Patients with schizophrenia often experience poor clinical outcomes, with a recent cohort study by Crump et al demonstrating that patients with schizophrenia die 12-15 years earlier as compared with the general population [3]. Comorbid substance-related disorders have been shown to be powerful drivers of poorer clinical outcomes, including nonadherence to medication [4][5][6], disease relapse [7,8] and mortality [9] among patients with schizophrenia, making this a particularly vulnerable and challenging-to-treat subpopulation. The impacts of substance use on disease management, specifically on adherence and relapse, are complex and hypothesized to result from both the impacts of active substance use on cognition and judgment and from the direct psychotogenic effects of some substances (e.g., cannabis) [10].…”

Poor medication adherence and risk of relapse associated with continued cannabis use in patients with first-episode psychosis: a prospective analysis

“…There is poor understanding about how risk factors such as cannabis use might affect outcome in psychosis. Previous studies9, 14 have shown that the effect of cannabis use on risk of relapse was reduced when medication adherence was controlled for, suggesting that cannabis use could adversely affect psychosis outcome partly by influencing adherence to antipsychotic medication. This is consistent with independent evidence from a meta-analysis 15 suggesting a significant effect of continued cannabis use on adherence to antipsychotic medication in patients with psychosis (p<0·0001), which was also confirmed by the five studies9, 12, 16, 17, 18 that investigated this issue subsequently.…”

Does Cannabis Composition Matter? Differential Effects of Delta-9-tetrahydrocannabinol and Cannabidiol on Human Cognition

“…Interest in the effects of cannabis on human cognition stems from evidence regarding its role as the most widely used illicit drug [1] as well as an important risk factor for the development of psychosis [2, 3] and its relapse [4–8], the latter being also consistent with evidence that delta-9-tetrahydrocannabinol (∆9-THC), the main psychoactive ingredient of the Cannabis sativa plant, can induce transient psychotic symptoms upon acute administration in healthy volunteers [9–11]. This body of research is also consistent with independent evidence of endocannabinoid system abnormalities in psychosis [12], a disorder characterized by abnormalities in different cognitive processes [13].…”