The long-term effects of psychotherapy added to pharmacotherapy on morning to evening diurnal cortisol patterns in outpatients with major depression

Background: Psychotherapy added to pharmacotherapy results in greater improvement in clinical outcomes than does pharmacotherapy alone. However, few studies examined how psychotherapy coupled with pharmacotherapy could produce a long-term protective effect by improving the psychobiological stress response. Methods: The researchers recruited 63 subjects with major depressive disorder (MDD) in an outpatient department of psychiatry at a general hospital. The randomly assigned subjects formed 2 groups: 29 in combined therapy (COMB) and 34 in monotherapy (MT). The COMB included 8 weekly body-mind-spirit group psychotherapy sessions added to pharmacotherapy. MT consisted of pharmacotherapy only. The outcome measures, collected at the subjects' homes, included the Beck Depression Inventory II (BDI-II), the State Trait Anxiety Inventory (STAI) and salivary cortisol on awakening, 45 min after awakening, and at 12.00, 17.00 and 21.00 h. Evaluation of outcome measures was at baseline condition, and at months 2 (end of additional psychotherapy), 5 and 8. Results: While the decreases in symptoms of depression were similar between COMB and MT (p > 0.05), the reductions in anxiety state were greater in COMB than in MT during the 8-month follow-up (p < 0.05). A steeper diurnal cortisol pattern more likely occurred in COMB than in MT in the 3 follow-up periods (p < 0.05, p <0.001 and p < 0.01). Conclusions: The superior outcomes of group psychotherapy added to pharmacotherapy for MDD outpatients could relate to decreasing the anxiety state and to producing long-term impacts on positive stress endocrine outcomes seen as a steeper diurnal cortisol pattern.