There is little data to indicate whether or not patients with chronic mental illness can provide self-report QOL data or if informant reports can substitute the patients’ ratings. We evaluated patient-proxy agreement in patients with schizophrenia and bipolar disorder and compared levels of agreement according to the relationship between patient-proxies.

WHOQOL-BREF and SF-36, two of the most popular quality of life instrument were administered to 82 schizophrenia-proxy and 50 bipolar disorder patient-proxy pairs.

Proxies of schizophrenia patients rated patients’ QOL lower than the patients themselves. Agreement between patients and proxies on the four main domains of QOL was moderate to good. Moreover, the agreement between patients’ and proxies’ ratings was higher when the proxy was a mother or spouse compared to father.

These findings suggest that proxy rating of QOL can be used as a reasonable estimate of the patients’ rating of QOL in schizophrenia and bipolar patients, at least in Korea. Knowing which domains of QoL are affected in specific psychiatric disorders can help clinicians focus on particular QoL domains during the diagnostic process and to define adequate treatment goals. Therefore, the assessment of QoL may be an important part of the diagnostic process because it can give insight into the areas of functioning in which a patient is suffering the most.