This research seeks to extend the knowledge gained from the pilot trial. A randomised trial will be conducted on a larger sample size of patients with alcohol use disorder and a co-morbid depressive disorder (including bipolar depression) for an extended duration (6 months of supportive text messages and 1 year follow-up instead of 3 months text messages with 6 months follow-up in the pilot trial). It is hypothesised that patients receiving supportive text messages will report significantly greater cumulative abstinence duration as well as significantly less relapses, hospitalizations and mood symptoms than those not receiving such messages. It is anticipated that this technology intervention for relapse prevention will be acceptable to patients as well as cost effective.