Clinical factors significantly associated with treatment resistance in unipolar depression according to the studies of the GSRD (European Group for the Study of Resistant Depression)
| Comorbid anxiety disorder (Souery et al., 2007) |
| Comorbid panic disorder (Souery et al., 2007; Zaninotto et al., 2013) |
| Current suicidal risk (Souery et al., 2007; Zaninotto et al., 2013; Balestri et al., 2016) |
| Severity of the current episode (Souery et al., 2007; Balestri et al., 2016) |
| Number of psychiatric hospitalizations (Souery et al., 2007; Zaninotto et al., 2013) |
| Social phobia (Souery et al., 2007) |
| Recurrent episodes vs. single episodes (Souery et al., 2007) |
| Early age of onset (<18 yr) (Souery et al., 2007) |
| Melancholic features (Souery et al., 2007; Zaninotto et al., 2013) |
| Psychotic features (Zaninotto et al., 2013) |
| Nonresponse to first antidepressant treatment lifetime (Souery et al., 2007) |
| Personality disorder (DSM-IV criteria) (Souery et al., 2007) |
| Long duration of the current depressive episode (Zaninotto et al., 2013; Balestri et al., 2016) |
| Outpatient status (Balestri et al., 2016) |
| First-/second-degree psychiatric antecedents (Balestri et al., 2016) |
| Occurrence of adverse effects during the treatment (Balestri et al., 2016) |
| High occupational level (Mandelli et al., 2016) |
DSM-IV, fourth version of the Diagnostic and Statistical Manual of Mental Disorders.