Remission onset and relapse in depression: An 18-month prospective study of course for 100 first admission patients

Background: Few prospective studies of course for first admission depressives are reported. Methods: One hundred consecutive depressed inpatients were followed prospectively over 18 months. Course was defined operationally using the Hamilton Depression scale and ICD-10 criteria. Results were analysed using life-tables. Results: The cumulative probabilities of remission onset by 3 and 18 months were 0.67 (95% C.I.=0.57–0.77) and 0.82 (95% C.I.=0.74–0.90). The cumulative probability of relapse was 0.25 (95% C.I.=0.15–0.35); 53% of those relapsing did so in the first 2 months. Younger age at onset, longer illness length, higher depression and anxiety ratings, predicted delayed remission onset. ICD-10 episode severity predicted relapse. Conclusions: The chances of remission onset at 3 months and relapse were increased relative to other studies; risk of chronicity was similar. Predictors of outcome to emerge were similar to other studies. Clinical implications: Adoption of these remission onset criteria may identify earlier (at 3 months), subjects at high risk of chronicity. After remission onset, subjects with severe illnesses warrant careful follow-up to detect relapse, particularly during the first 2 months. Limitations: The operational criteria used were different to other prospective studies. Relatively few psychosocial variables were included in the analysis.