Substance use and psychosis

Clinical psychologist Shane Rebgetz

Clinical psychologist Shane Rebgetz works with young people with severe mental health difficulties and substance use and psychosis. Shane, who researched substance use and psychosis for his PhD, says people with psychosis who use cannabis have much worse outcomes, but treatments typically have only limited effects that are poorly sustained.

“My program of research explored how people with psychosis cease using cannabis without substantial assistance to see if this shed light on how treatments could be improved,” Shane says.

“The studies suggested that greater focus on employment, separate accommodation, and social and emotional support for cessation would result in stronger outcomes than at present. Similar reasons were found for strategies to maintain a reduction in use while relapse was associated with substance using peers, and problems with relationships and negative emotions.”

Through his clinical work with people with psychosis and substance use Shane noticed that a cohort of these people were able to cease using substances of their own accord. At the same time, he was struggling to assist other clients to reduce their substance use.

“As a result I was interested in seeing what I could learn from those who stopped using substances with the hope that these leanings would support the reduction of substance use in the cohort that were struggling with cessation of use,” he says.

Shane’s thesis consisted of seven published papers that included a systematic review of the literature, two metaanalysis identifying the extent of reduction in control groups, cross-sectional studies of two existing data sets seeking baseline predictors of a reduction in substance use, and were two mixed-methods studies focusing largely on qualitative analysis of reasons for cessation of substance use in people with psychosis.

In the last study, 22 participants were recruited from local mental health services. The findings will help improve interventions for substance use in people with psychosis.

“The research will assist mental health practitioners to improve their current treatment approaches. It also increases hope in that people can naturally recovery from substance use,” Shane says.

Further research will be undertaken to evaluate the integration of the results from the body of research into clinical interventions.