Latent class analysis of Temperance Board registrations in Swedish male-male twin pairs born 1902 to 1949: searching for subtypes of alcoholism

Background. Alcoholism is clinically heterogeneous. We have attempted to identify and Validate subtypes of broadly defined alcoholism. Methods. Latent class analysis (LCA) was applied to data on the number, age at onset and reasons for temperance board registration (TBR) in all male-male twin pairs of known zygosity born in Sweden from 1902-1949. Results. Of the five classes identified, two were relatively common: single-cause registrant - drunk (SCR-D); and early-onset multiple-cause registrant (EO-MCR). In contrast to the SCR-D class, the EO-MCR class was characterized by: (i) earlier age at first TBR; (ii) higher number of TBRs; (iii) TBRs for drunk driving and alcohol-related crimes; (iv) much higher risk for alcohol-related imprisonment and hospitalization; (v) higher levels of neuroticism and novelty-seeking; and (vi) much greater risk for TBR in co-twins. In twin pairs concordant for TBR, concordance for LCA-derived class assignment far exceeded chance expectation, more so in monozygotic than in dizygotic pairs. Conclusions. Alcoholism is aetiologically as well as clinically heterogeneous. The two most common subtypes identified in these analyses bear substantial but imperfect resemblance to previously proposed typologies.