Extending previous research on the independent risks associated with an early AO and an early AI, the current study found that when considered simultaneously, an early AO and a quick progression to drinking to intoxication are both important risk factors for heavy drinking and problems during the years spanning senior year of high school through senior year of college. Although the magnitude of the direct effects was larger for AO than delay, this was primarily due to the negative correlation between AO and delay. Accounting for the indirect protective effects of an early AO operating through a longer delay, the net effects of AO and delay on the intercepts of heavy drinking (β = −0.25 for AO and β = −0.27 for delay) and problems (β = −0.14 for AO and β = −0.17 for delay) were similar.
