Reductions in alcohol consumption following participation in ‘Dry January’: an investigation of the psychological and social factors underpinning change

Dry January may help to reduce alcohol consumption and associated harms. Participation is associated with reductions in alcohol consumption six months later. Increased drink refusal self-efficacy (DRSE), belief in one’s ability to refuse alcohol, appears to mediate these reductions. Other mechanisms of change are yet to be identified. This thesis aimed to establish the psychological and social changes underlying reductions in alcohol consumption among heavy drinkers following participation in Dry January.
A mixed methods approach was used. First, a prospective observational survey study compared outcomes at six-months for ‘official’ Dry January participants (registered with access to online supports) with ‘unofficial’(unregistered) participants and people not participating (Chapter III). Alcohol consumption and relevant psychosocial constructs were measured. In Chapter IV, semi-structured interviews explored strategy use during and following Dry January. A second prospective study (Chapter V) addressed limitations of the first and incorporated findings from the interviews. Additional constructs were assessed including drinker identity and use of online supports. Finally, analysis of smartphone app data (Chapter VI) examined changes in consumption nine months post-January and investigated the impact of app engagement on these changes.
‘Official’ Dry January participation was associated with reductions in alcohol consumption six and nine months later. Greater reductions relative to people not participating suggest changes were not entirely attributable to seasonal variation in consumption. Greater reductions relative to ‘unofficial’ participants suggest access to online supports may enhance outcomes. Increased consumption following January was evident in a substantial minority of ‘official’ app users. Strategy use was dynamic and evolved post-January: minimal differences in approaches were observed between ‘official’ and ‘unofficial’ participants. Among ‘official’ participants, baseline consumption, motivation, DRSE, drinker identity, abstinence and use of strategies and the app post-January were associated with six-month consumption. Harnessing relevant psychological and social factors may help maximise the benefits of Dry January.