Different short-term therapies, mainly with short follow-ups, seem equally effective treatments of mood disorders. The Helsinki Psychotherapy Study is the only published randomized trial on the effectiveness of short-term and long-term therapies during a longer follow-up. During a 5-year follow-up, patients' recovery from symptoms and improvement in work ability were greater in long-term therapy than in two, equally effective, short-term therapies. The short-term therapies were, however, more cost-effective, but many patients in them did not recover. More randomized clinical trials and cohort studies with long follow-ups on the efficacy, sufficiency and suitability of short- and long-term therapy are thus needed.