Be Aware of Vulnerabilities

Stress and behaviors during deployment sometimes can set off the disease in servicemembers who demonstrated no obvious schizophrenia symptoms at enlistment, adds Cheryl Corcoran, MD, assistant professor of clinical psychiatry at Columbia University Medical Center and director of the Center of Prevention and Evaluation at the New York State Psychiatric Institute,

“I think there’s a lot of evidence to suggest that stress as well as exposure to different drugs like cannabis or methamphetamine in people who have a pre-existing vulnerability to psychosis might trigger onset or exacerbate existing attenuated symptoms,” says Corcoran. Cortisol is released throughout the body during the fight-or-flight response and, she points out, “And dopamine release is increased in the brain, which in vulnerable individuals can lead to psychotic symptoms.” 

Earlier this year, a metanalysis of more than 80 studies found that the mean age at onset of psychotic disorders, including schizophrenia, was more than 2.5 years earlier for marijuana users compared with nonusers.¹

Corcoran lists a number of ways to help identify which individuals might be vulnerable to developing schizophrenia.

One, for example, is a family history of psychosis, especially involving a first-degree family member and combined with drug use.

“There are certain genes related to vulnerability to having psychotic symptoms when exposed to stress or using marijuana,” Corcoran explains. For example, she notes, the enzyme Catechyl-O-Methyl-Transferase breaks down dopamine – which is involved in psychosis, but none of these are “black or white” situations, meaning the risk factor alone is not enough to predict psychosis.

More indicative of vulnerability, Corcoran continues, are clinical symptoms that are sub-threshold – i.e., a diagnosis has not yet been reached. “Someone might have schizotypal features such as being odd, having magical thinking, or social awkwardness; that represents vulnerability,” she says.

A key indication would be unusual thought content that evolves over time into a delusion, says Corcoran, adding, “This also includes suspiciousness; that’s a real risk for psychosis.” In addition, she says military health providers should look for “perceptual disturbance, like hearing voices.” Before actually hearing voices, she explains, the individual may hear knocking, or their name being called in the wind. “These are subtle things, but you can start to see patterns.”         

Other than looking for those symptoms, “there is not a really good screen,” Corcoran says, adding “What you might want to do is de-stigmatize these kinds of symptoms so the few people who do have them would seek help.”

Questionnaire May Be Beneficial

That may be changing based on research published this summer in the journal Schizophrenia Research on the use of a prodormal self-report questionnaire to help detect early stages of schizophrenia, before full-blown psychosis develops.²

In its full form, the 92-item questionnaire, which takes approximately 20 minutes to complete, focuses on four major areas:

1.             Milder forms of positive symptoms (i.e., “unusual thinking” or “perceptual               abnormalities.”)
2.             Negative symptoms (which can include limited facial expressions of emotions.)
3.             Disorganized symptoms (i.e., odd, difficult to understand behavior.)
4.             General symptoms (which can include depression and the ability to perform daily            activities of living.   

Rachel Loewy, PhD, of the Department of Psychiatry at UCSF, and colleagues used a brief version of the questionnaire with adolescents and young adults. “Endorsement of three or more positive symptoms on the PQ-B (Podromal Questionnaire Brief version) differentiated between those with prodromal syndrome and psychotic syndrome diagnoses on the SIPS versus those with no SIPS diagnoses with 89% sensitivity, 58% specificity, and a positive Likelihood Ratio of 2.12,”the researchers wrote. “A Distress Score measuring the distress or impairment associated with endorsed positive symptoms increased the specificity to 68%, while retaining similar sensitivity of 88%. These results suggest that the PQ-B may be used as an effective, efficient self-report screen for prodromal psychosis syndromes when followed by diagnostic interview, in a two-stage evaluation process in help-seeking populations.”

References

1: Large M, Sharma S, Compton MT, Slade T, Nielssen O. Cannabis Use and Earlier

Onset of Psychosis: A Systematic Meta-analysis. Arch Gen Psychiatry. 2011

Jun;68(6):555-61. Epub 2011 Feb 7. PubMed PMID: 21300939.

2. Loewy RL, Pearson R, Vinogradov S, Bearden CE, and Cannon TD. Psychosis risk screening with the Prodromal Questionnaire — Brief Version (PQ-B). Schizophr Res. 2011 Jun;129(1):42-6. Epub 2011 Apr 20.

Back to August Articles