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.