A new study published in the current issue of Psychotherapy and Psychosomatics provides alarming data on the likelihood that antidepressant drugs may produce untoward effects.
Mixed depression is narrowly defined in the DSM-IV and somewhat broader in the DSM-5, although both exclude psychomotor agitation as a diagnostic criterion. This article proposes a clinical description for defining mixed depression, which emphasizes psychomotor excitation.
Two hundred and nineteen consecutive outpatients were diagnosed with an mixed depression episode using criteria proposed by Koukopoulos et al. Results showed that the most frequent mixed depression symptoms were psychic agitation or inner tension (97%), absence of retardation (82%), dramatic description of suffering or weeping spells (53%), talkativeness (49%), and racing or crowded thoughts (48%). Mixed depression was associated with antidepressants in 50.7% of patients, with similar frequency for tricyclic antidepressants (45%) versus selective serotonin reuptake inhibitors (38.5%).
Positive predictors of antidepressant-associated mixed depression were bipolar disorder type II diagnosis, higher index depression severity, and higher age at index episode. Antipsychotic or no treatment was protective against antidepressant-associated mixed depression.
Mixed depression, defined as depression with excitatory symptoms, can be clinically identified, is common, occurs in both unipolar depression and bipolar disorder, and is frequently associated with antidepressant use. If replicated, this view of mixed depression could be considered a valid alternative to the DSM-5 criteria for depression with mixed features.