Problem drinking has become more common in the US in recent decades. The San Diego Prospective Study (SDPS), which began in 1978, revealed an almost two-fold increase in alcohol problems and alcohol use disorder among the current generation of young-adult drinkers compared to their fathers ?with similar increases reported in large nationwide surveys. In a new report of the SDPS published in the journal Alcoholism: Clinical & Experimental Research, investigators from the University of California explore potential reasons for these cross-generation differences.

The researchers analyzed data from interviews with over four hundred of the original (all male) participants of the SDPS, obtained when they were aged around 30 years, in addition to recent data from over two hundred of their adult offspring (male and female), obtained at a similar age using the same questions. By applying a range of analytical approaches, the team were able to identify three characteristics that were consistently associated with greater alcohol problems in the second generation.

First, the data highlight a more robust relationship to alcohol problems for offspring who have what is known as a low "level of response" to alcohol ?ie for those who from an early age need to drink larger quantities of alcohol to become intoxicated. Although the actual level of response to alcohol remained constant across the generations, a low level was more strongly associated with alcohol problems in the second generation. Second, both male and female offspring were more likely than the previous generation to have more positive expectations of the effects of alcohol ?such as a belief that drinking makes parties more fun. Higher "alcohol expectancies" were strongly associated with alcohol problems among the offspring. Third, the adult children (particularly males) scored more highly than their forebears on measures of impulsivity, another significant predictor of alcohol problems in the second generation.

The availability of data across generations of the same families offered a unique opportunity to explore just some of the factors that may have contributed to the substantial rise in alcohol problems and alcohol use disorder in recent decades. If replicated in further studies, the findings could inform strategies to mitigate the development of alcohol problems among the current generation of young adult drinkers.