Factors associated with remission from primary psychosis appear to be also
associated with remission from substance-induced psychosis.
Those factors include better premorbid adjustment, shorter duration of
untreated psychosis, better insight into psychotic symptoms, and lower
severity of psychotic symptoms, according to a report in the October
Lead author Carol Caton, Ph.D., told Psychiatric News that the
similarity in factors associated with remission suggest some underlying
neurobiological similarity between primary psychosis and substance-induced
"The predictors for remission in both diagnostic groups were the
same," she said. "That hadn't been documented before. What it
suggests is that whatever the biological mechanism is that causes people to
become psychotic, there must be some similarity whether the psychosis is
primary or substance induced."
She is a professor of clinical public health for psychiatry and
sociomedical science at the Columbia University College of Physicians and
Surgeons and director of the Columbia Center for Homelessness Prevention
In the study, funded by the National Institute on Drug Abuse, Caton and
colleagues examined rates and predictors of psychosis remission at one-year
follow-up for 319 patients with a history of recent substance use who were
admitted to the emergency department with psychotic symptoms of recent onset.
Of these, 133 had substance-induced psychosis and 186 had primary
The diagnostic distinction between a primary psychotic disorder and a
psychotic disorder that is substance induced was made using the Psychiatric
Research Interview for Substance and Mental Disorders, an
interviewer-administered research diagnostic instrument developed to assess
psychiatric and substance use comorbidity using DSM-IV criteria.
"This gave us a sample of people who were both psychotic and
substance users and allowed us to look at the differences in remission rates
and predictors for remission between those with primary psychosis and those
with substance-induced psychosis," she said.
At one-year follow-up, 50 percent of patients with primary psychosis were
in remission, compared with 77 percent of patients with substance-induced
psychosis. Premorbid adjustment was assessed using the Positive and Negative
Caton told Psychiatric News that the higher rate of remission for
substance-induced psychosis was not surprising. But she noted that 23 percent
of those patients had not remitted and continued to be symptomatic, evidence
of the potentially chronic nature of a substance-induced psychosis.
"It underscores the importance of getting people into
treatment," she said. "There is a clinical lore that
substance-induced psychosis is not as serious, but without effective treatment
these people can develop a persistent psychotic disorder. It is not a benign
"We think aggressive, assertive treatment is needed," she said."
That hasn't been a widespread practice. If people are seen in a psych
[emergency department], and their symptoms remit in a day or two with a
drug-free period, they are sometimes released with a referral to a treatment
center. But that doesn't mean the patient follows the referral. We think there
should be more assertive ways to make certain that people get
Caton said that among patients with substance-induced psychosis, the most
common substances involved were, in rank order, cannabis, alcohol, cocaine,
and hallucinogens. A smaller percentage of patients used heroin or other
The same rank order of substances was found for individuals with primary
In 39.6 percent of the substance-induced psychoses, two or more substances
were used, with cannabis and alcohol the most common combination, followed by
alcohol and cocaine, Caton told Psychiatric News.
In the Schizophrenia Bulletin report, Caton and colleagues stated
that the "stress-diathesis model suggests that substance abuse may
precipitate psychosis among some people who would otherwise be vulnerable but
notpsychotic." And they cited research showing that individuals who are
vulnerable to psychosis because of a specific polymorphism of the
catechol-O-methyltransferase gene increase their vulnerability if
they are heavy cannabis users in adolescence.
A second possibility is that psychosis may emerge earlier in
substance-using vulnerable individuals who would otherwise develop the illness
later, they suggested.
"This sets the stage for neuroscience to take over and explore the
underlying causes of substance-induced psychosis," Caton told
"Predictors of Psychosis Remission in Psychotic Disorders That
Co-occur With Substance Use" is posted at<http://schizophreniabulletin.oxfordjournals.org/cgi/content/full/32/4/618>.▪