Clinical utility of biomarkers of the hand in the diagnosis of schizophrenia.

A number of biomarkers were assessed in photos and prints of the hands of 95 patients with a variety of mental disorders to determine whether patients with schizophrenia could be distinguished from the others. Patients were recruited as consecutive admissions from an outpatient psychiatric day hospital population. Fourteen patients were diagnosed with schizophrenia/schizoaffective disorder and 81 were diagnosed with other mental disorders. A discriminant analysis yielded an overall 80% correct classification, with a sensitivity (schizophrenia patients identified correctly) of 78.6% and a specificity (non-schizophrenia patients identified correctly) of 80.2%. Significant differences were noted in the proximal interphalangeal joint, eponychium of the middle digit and fingernails. To determine biomarker frequency distribution patients with bipolar disorder were then compared to those with schizophrenia/schizoaffective disorder and then to patients with PTSD. The former yielded an overall 78.6% correct classification, with a sensitivity of 71.4% and a specificity of 85.7% and with similar biomarker frequency distribution for bipolar disorder as for the entire non schizophrenia group. The latter comparison yielded an overall 58.6% correct classification, with no significant differences between the features. The application of these biomarkers in clinical practice could constitute an additional tool for the psychiatrist in cases lacking diagnostic clarity.

Biometric parameters of the hand as an index of schizophrenia--a preliminary study.

Since abnormalities in distal upper limb development are among the minor physical anomalies associated with schizophrenia we attempted to determine whether patients with schizophrenia can be identified on the basis of specific morphologic and dermatoglyphic features of the hand. Photographs and prints of the hands of 38 patients with schizophrenia and those of 42 control subjects were evaluated and graded on 13 biometric parameters. Results were statistically evaluated. A combination of three of the parameters was found to have good predicting abilities to distinguish between schizophrenics and controls. Subjects having high values in these three parameters were found to have a higher propensity to be defined as schizophrenics. In order to define a simple rule for classifying subjects we chose a criterion of having a value of 3 (in a scale from 1 to 3) in at least one of these three discriminating variables. This rule yielded an overall accuracy of 81.2%. Among controls, 85.7% of subjects did not fulfill such criteria, while 14.3% were defined as false positives. Among schizophrenics 76.3% achieved this condition while 23.7% were false negatives. The technique's objectivity and ease of application could facilitate the diagnosis of this disease.