CRP Levels May Indicate Schizophrenia Prognosis

Levels of C-reactive protein (CRP) indicating low-grade inflammation are associated with worsening scores on several psychometric scales and a poorer overall prognosis over a 1-year period in outpatients with stable schizophrenia.

Schizophrenia is a mental disorder characterized by abnormal social behavior and failure to understand reality. Common symptoms include false beliefs, unclear or confused thinking, hearing voices that others do not, reduced social engagement and emotional expression, and a lack of motivation.


Scientists at the University of Oviedo (Oviedo, Spain) studied 50 stable outpatients of whom 62% were male, and the mean age was 31.1 years, who had been diagnosed with schizophrenia for fewer than 10 years. The team stratified subjects according to having low-grade inflammation, 14 who were defined with 3 to 10 mg/L CRP or 36 with normal CRP levels defined as equal to or less than 3mg/L CRP. The team excluded patients from the study who had greater than 10mg/L CRP, which represented acute inflammation.

During the course of the trial, the overall patient population demonstrated significantly improved scores from baseline. Scores after one year improved on the Positive and Negative Syndrome Scale-Positive, (PANSS) -General and -Total scale (range: 55.8 to 59.9); PANSS-General scale (range: 26.9 to 29.7); and the Clinical Assessment Interview for Negative Symptoms (CAINS)-Expression scale (range: 4.9 to 5.7). The team observed differences between the high versus normal CRP groups, however, in the duration of illness (6 versus 3.5 years; and in body mass index (BMI), 30.3 versus 26.5.

Patients with low-grade inflammation and elevated levels of C-reactive protein (CRP), however, showed worsening scores during the year, which were represented by positive score values. These patients scores were poorer compared with those of patients with normal CRP levels on all PANSS scales; the PANSS Positive scale scores were 0.86 versus -1.3; PANSS Negative scores were 0.86 versus -1.2, the PANSS General scores were 0.93 versus -4.2, and the PANSS Total scores were 2.6 versus -6.7 for patients with high versus normal CRP levels, respectively for all comparisons.

Leticia Gonzalez-Blanco MD, the lead author of the study, said, “By multiple regression analyses, only CRP levels of 3 to 10 mg/L were associated with a worse clinical course on the PANSS [Positive and Negative Syndrome Scale]-Positive, -General and -Total scales]. Higher baseline CRP levels may be a biomarker of poor clinical course in the first 10 years of schizophrenia.” The study was presented on March 5, 2018, at the 26th Congress of the European Psychiatric Association held in Nice, France.

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University of Oviedo