Supportive text messages have the potential to provide personalised support for patients with depression and co-morbid Alcohol Use Disorder (AUD). The objectives of the study are to explore the six months follow-up effects of twice daily supportive text messages delivered over a three month period on mood and abstinence outcomes for patients with depression and co-morbid AUD.

Participants (n=54) with a DSM IV diagnosis of unipolar depression and AUD who completed an in-patient dual diagnosis treatment programme were randomised to receive twice daily supportive text messages (n = 26) or a fortnightly thank you text message (n = 28) for three months. Primary outcome measures at six months were Beck's Depression Inventory (BDIII) scores and Cumulative Abstinence Duration (CAD). Trial registration: NCT0137868.

Unlike at three months, there was no statistically significant difference in six month BDI-II scores between the intervention (n=24) and control (n=24) groups; 13.28 (SD=8.7) vs. 15.08 (SD=11.37) respectively after adjusting for the baseline scores, F (1, 45) =0.192, p=0.66. There was also no significant difference in CAD between the text message group and the control group: 84.14 days (9.20) vs. 74.73 days (28.97), t= 1.422, df=41, p=0.16. However, patients in the intervention group had significantly higher days to first drink compared to those in the control group: 119.9 (47.7) vs. 62.4 (44.9), t=2.99, df=22, p=0.01.

The effects of supportive text message intervention were not sustained beyond the period that the patients were receiving the intervention.