Background Annual gains in life expectancy in Scotland have been slower in recent years than in the previous two decades for males and females. Similar slowdowns or even reversals have been observed in England, Wales, Northern Ireland and the USA. This contribution explores the contribution of specific causes of death to the changes in mortality by age and cause for two time periods: 2000–02 to 2012–14 and 2012–14 to 2015–17.

Methods Life expectancy at birth was calculated from death and population counts available from National Records of Scotland (NRS), disaggregated by five year age categories and by ICD-10 underlying cause of death. Arriaga’s method of life expectancy decomposition was applied to produce estimates of the contribution of different age groups and underlying causes of death to life expectancy at birth in each of the two periods.

Results Life expectancy trends deteriorated after 2012–14 and life expectancy subsequently fell. The worsening trend involved increased inequalities as it was more profound with increasing area deprivation. Almost all age groups saw a worsening of trends in the later time periods and this was also seen across almost all causes of death. In particular, the previously observed rapid improvements in circulatory causes which benefited those aged 55–84 years most, more than halved. There were also absolute increases in mortality rates for those aged 35–49 years due in large part to increases in drug-related deaths; and amongst those aged 90+ years due to increased mortality from dementia/Alzheimer’s.

Conclusion Although there has been substantial focus up to now on the role that increased mortality amongst the oldest groups has played in the recent life expectancy trends, more attention needs to be paid to the role that the slowdown in improvement for circulatory causes across a much wider age group has played, as well as the importance of rising drug-related deaths in younger adults. Future research should seek to explain the changes in mortality trends for all age groups and causes of death and policymakers should act to protect the social security system and public services that are likely to be part of the causes of the recent trends.