The life course of schizophrenia: age and symptom dimensions

The life course of schizophrenia has eluded description for several reasons, including fluctuations in diagnostic criteria over the past century, and dramatic changes in treatment and expectations of the mentally ill. This study compared symptoms within a group of patients spanning ages 14 through 73. The three symptom dimensions (psychotic, disorganized and negative) were examined separately in relation to age. Using a multivariate analysis, the effects of age, sex and institutional status were found to have main effects for symptom severity with no interaction effects. The effect of age was significant in the negative direction for positive and disorganized symptoms. Age was specifically associated with decreased hallucinations, delusions, bizarre behavior and inappropriate affect. There was no age effect for formal thought disorder, nor was there an age effect for negative symptoms. Institutionalization was associated with greater symptom severity in all dimensions. Male gender was associated with greater severity of negative symptoms. We conclude that psychotic and disorganized symptoms are likely to be of lesser severity in older patients with schizophrenia, while negative symptoms tend to persist. Clinically, these findings suggest that medications targeting negative symptoms may confer the greatest benefit in treating the older patient with schizophrenia.