Impact of Cannabis Use on Long-Term Remission in Bipolar I and Schizoaffective Disorder

Objective

To investigate the impact of regular cannabis use on long-term remission of mood symptoms in bipolar spectrum disorders.

Methods

The 24-month prospective observational study included patients (n=239) with bipolar I disorder and schizoaffective disorder, bipolar type. Participants were classified as regular cannabis users (three times or more per week) or non-users. The primary outcome measure was the achievement of remission on the evaluations during the 24 months.

Results

Of the 234 participants for whom data was available, 25 (10.7%) were regular cannabis users, and the group comprised significantly more males than females. In the total population, cannabis use was significantly associated with decreased likelihood of remission during the 24-month follow-up period. Subgroup analyses showed that cannabis use was significantly associated with lower remission rates on the Hamilton Depression Rating Scale in females (n=139) and patients prescribed mood stabilizers alone (n=151), whereas in males (n=95) and patients prescribed olanzapine and/or a mood stabilizer (n=83), cannabis use was significantly associated with lower remission rates on the Young Mania Rating Scale. Remission rates were lowest in the concurrent cannabis and tobacco smoking group (n=22) followed by the tobacco smoking only group (n=97), and the non-smoker group (n=116). The post-hoc analysis revealed that all remission rates were significantly lower in the concurrent cannabis and the tobacco smoking group compared to the non-smoker group.

Conclusion

Cannabis use negatively affects the long-term clinical outcome in patients with bipolar spectrum disorders. A comprehensive assessment and integrated management of cannabis use are required to achieve better treatment outcomes for bipolar spectrum disorders.     

Cannabis and psychometrically-defined schizotypy: Use, problems and treatment considerations

Cannabis use is associated with onset of psychosis in individuals vulnerable for developing schizophrenia-spectrum disorders. The present study addressed three knowledge gaps pertaining to this issue: 1) clarifying the incidence of cannabis use in schizotypal individuals, 2) examining how cannabis use is related to psychosocial and physiological problems in schizotypy and interest in treatment, and 3) examining how cannabis use is associated with positive, negative and disorganization features of schizotypy. Scores from a measure of schizotypal traits were used to trichotomize 1665 young adults into schizotypy (top 5% of scorers), non-schizotypy (bottom 50% of scorers) and “unconventional” (scorers within the 50th to 85th percentile) groups. Nearly a quarter of the schizotypy group endorsed cannabis use at least weekly, a rate nearly two to four times that of the other groups. The schizotypy group also reported a much greater frequency of cannabis-related problems compared to the other groups. Despite this, interest in treatment for cannabis use in the schizotypy group was not elevated. Interestingly, 85% of individuals in the schizotypy group reported interest in psychological/psychiatric treatment more generally. Cannabis use was not associated with abnormal patterns of positive or disorganized schizotypy traits in the schizotypy group relative to the other groups. However, cannabis use was associated with lower severity of negative traits. Implications of these results are discussed.     

Differential dysfunctions related to alcohol and cannabis use disorder symptoms in reward and error-processing neuro-circuitries in adolescents

Alcohol and cannabis are two of the most commonly used substances by adolescents and are associated with adverse medical and psychiatric outcomes. These adverse psychiatric outcomes may reflect the negative impact of alcohol and/or cannabis abuse on neural systems mediating reward and/or error detection. However, work indicative of this has mostly been conducted in adults with Alcohol and/or Cannabis Use Disorder (i.e., AUD and CUD), with relatively little work in adolescent patients. Furthermore, of the work that has been conducted in adolescents, groups were based on categorical diagnoses of AUD and/or CUD, so the relationship between AUD and/or CUD symptom severity in adolescents and neural dysfunction is unclear. We used a Monetary Incentive Delay (MID) task to examine the relationship between AUDIT and/or CUDIT scores and functional integrity of neuro-circuitries mediating reward processing and error detection within 150 adolescents. Our findings indicate that AUDIT score is negatively related to activity in reward processing neuro-circuitry in adolescents. However, CUDIT score is negatively related to activity in brain regions involved in error detection. Each of these relationships reflected a medium effect size (Partial-η² 0.09-0.14). These data suggest differential impacts of AUD and CUD on reward versus error detection neuro-circuitries within the adolescent brain.     

The Potential Impact of Recreational Cannabis Legalization on the Prevalence of Cannabis Use Disorder and Psychotic Disorders: A Retrospective Observational Study

Objectives:The principal objective of our study was to document the short-term impact of the legalization of recreational cannabis on active cannabis use, cannabis use disorder, and various psychotic disorders.Methods:We carried out a retrospective observational study of patients who were at least 12 years old and who had visited a psychiatrist in the emergency unit of the Centre hospitalier universitaire de Sherbrooke (CHUS). We included all the consultations of this type over a 5-month period, immediately following the legalization of recreational cannabis in Canada. We then divided our population into an adult (over 18) and teenager group (12 to 17) compared the data to the data from consultations made 2 years earlier, using a generalized linear mixed model.Results:We examined consultations in patients over 18 years old in prelegalization (n = 1,247) and postlegalization (n = 1,368) groups. We observed a statistically significant increase in the use of cannabis (28.0% to 37.1%; odds ratio [OR] = 1.81 [1.34 to 2.44], P = 0.00011) as well as an increase in diagnoses of active cannabis use disorder (17.7% to 24.3%; OR = 1.53 [1.13 to 2.08], P = 0.0064). The increase in cannabis use disorder was more prominent among patients between 18 and 24 years old (17.3% to 25.9%; OR = 2.27 [1.17 to 4.40], P = 0.015). We observed no statistically significant difference in terms of psychotic disorder diagnoses (27.4% to 29.2%; OR = 1.17 [0.84 to 1.63], P = 0.35)]. Conversely, we identified a greater proportion of patients who had a personality disorder diagnosis in the postlegalization period (39.6% to 44.9%; OR = 1.35 [1.02 to 1.80], P = 0.038). Examination of pediatric (under 18 years old) consultations revealed no statistically significant differences.Conclusion:Although an affirmative conclusion is tentative, the current findings suggest a first link between the legalization of cannabis in Canada and increased diagnoses of cannabis use disorder, as well as cannabis use in general among patients in a university hospital psychiatric emergency department.     

Peer influence and gender differences in problematic cannabis use among individuals with social anxiety

Despite epidemiological reports indicating that individuals with social anxiety disorder (SAD) are at heightened risk for cannabis use disorders (CUD), there is a dearth of research investigating the mechanisms underlying the nature of this co-occurrence. The present study examined the role of a well-established risk factor for cannabis use, peer influence, on the relationship between symptoms of SAD and CUD in a non-referred sample (N = 123). Lifetime symptoms of SAD and CUD were assessed using a structured diagnostic interview. SAD symptoms were significantly correlated with CUD symptoms and this relationship was moderated by peer use of both alcohol and cannabis. Further, a gender effect indicated that the relationship between symptoms of SAD and CUD occurred only in women. Implications of these novel findings are discussed.     

Cannabis use disorder and suicide attempts in Iraq/Afghanistan-era veterans

The objective of the present research was to examine the association between lifetime cannabis use disorder (CUD), current suicidal ideation, and lifetime history of suicide attempts in a large and diverse sample of Iraq/Afghanistan-era veterans (N = 3233) using a battery of well-validated instruments. As expected, CUD was associated with both current suicidal ideation (OR = 1.683, p = 0.008) and lifetime suicide attempts (OR = 2.306, p < 0.0001), even after accounting for the effects of sex, posttraumatic stress disorder, depression, alcohol use disorder, non-cannabis drug use disorder, history of childhood sexual abuse, and combat exposure. Thus, the findings from the present study suggest that CUD may be a unique predictor of suicide attempts among Iraq/Afghanistan-era veterans; however, a significant limitation of the present study was its cross-sectional design. Prospective research aimed at understanding the complex relationship between CUD, mental health problems, and suicidal behavior among veterans is clearly needed at the present time.     

Using the Autism-Spectrum Quotient to Discriminate Autism Spectrum Disorder from ADHD in Adult Patients With and Without Comorbid Substance Use Disorder

It is unknown whether the Autism-spectrum quotient (AQ) can discriminate between Autism Spectrum Disorder (ASD) and Attention Deficit and Hyperactivity Disorder (ADHD) with or without comorbid Substance Use Disorder (SUD). ANOVA’s were used to analyse the mean AQ (sub)scores of 129 adults with ASD or ADHD. We applied receiver operating characteristic (ROC) computations to assess discriminant power. All but one of the mean AQ (sub)scores were significantly higher for adults with ASD compared to those with ADHD. The SUD status in general was not significantly associated with AQ (sub)scores. On the Social Skills subscale patients with ASD and comorbid SUD showed less impairment than those without SUD. The cut-off score 26 yielded 73% correct classifications. The clinical use of the AQ in differentiating between ASD and ADHD is limited.