TYPOLOGY OF COMMON PSYCHIATRIC SYNDROMES - AN EMPIRICAL-STUDY

Background Diagnostic comorbidity is prevalent in psychiatry and may b e inadequately captured by the DSM -III/ III-R nosology. Methods The l ifetime presence of I I psychiatric diagnoses was determined by struct ured personal interviews of a population-based sample of 1898 female t wins. We used latent class analysis to derive an empirical typology. R esults Six classes provided the best fit to the data. Their mnemonics were: minimal disorder (60% of the sample), major depression - general ised anxiety disorder (19%), alcohol - nicotine (7%), highly comorbid major depression (5%) and eating disorders (3%).The validity of this t ypology was strongly supported by demographic, health, personality and attitudinal validators along with the significant monozygotic twin co ncordance for class membership. The typology superficially resembled D SM - III - R, but contained many differences. Major depression appeare d in three forms (alone, with generalised anxiety disorder and with co nsiderable comorbidity). Alcoholism-nicotine dependence and the variou s anxiety disorders formed discrete classes, but were also prominent i n other classes. Bulimia and anorexia were exceptional in their appear ance in a single class. Conclusions The DSM-III-Rand closely related D SM - IV nosology did not capture the natural tendency of these disorde rs to co-occur. Fundamental assumptions of the dominant diagnostic sch emata may be incorrect.