For many of us, raising a glass to toast the end of the working week is nothing out of the ordinary.
But spontaneous weekend drinks carry a 26 per cent increased risk of negative outcomes such as embarrassment, hangovers and blackouts, a study suggests.
Researchers followed 938 people aged 18 to 25 over a 14-week period and asked them to fill out regular assessments.
These captured both their planned intentions to drink and how much alcohol they actually consumed.
Negative consequences of drinking were also measured using a 24-point questionnaire.
This asked participants if they experienced the likes of hangovers, blackouts, saying or doing embarrassing things, taking foolish risks, being rude, feeling regret or putting on weight due to drinking.
Analysis revealed that on 17 per cent of days – nearly one in five – participants ended up drinking without having any prior intention to.
Unplanned drinking was more prevalent among the older young adults, challenging the view that self-control increases with maturity, the researchers found.
The team also discovered that frequent unplanned drinking was linked to a 26 per cent higher change of adverse alcohol-related consequences.
Social settings, especially weekend gatherings and the influence of friends, were significant contributors to this, they said.
Participants who had ‘drinking friends’ present were 12 times more likely to engage in unplanned drinking compared to those who had no friends present.
Meanwhile, unplanned drinking was significantly more common on weekends, with 82.5 per cent of unplanned drinking days occurring on Fridays and Saturdays.
They also discovered that negative urgency – an impulsivity trait reflecting a tendency to act rashly in response to negative emotions – was a strong predictor of unplanned drinking.
The study’s lead author Brian Suffoletto, from Stanford University, said: ‘Our findings highlight that unplanned drinking is strongly influenced by social context and individual risk factors.
‘Targeted interventions addressing impulsivity and peer influence could be key to reducing the harms associated with unplanned drinking.’
The findings appeared in the journal Addictive Behaviours, published by Elsevier. The team said their results have several important implications for interventions targeting young adults.
This could include teaching young adults to recognise and plan for high-risk social situations, developing strategies for responding to spontaneous drinking invitations and potentially recruiting supportive friends to help intervene during these occasions.
They also suggest that people could try develop ways to manage negative emotions without turning to alcohol, set drinking limits before social events and develop skills for navigating peer pressure.