Drug dose as mediator of treatment effect in antidepressant drug trials: the case of fluoxetine.

OBJECTIVE: This study aimed at investigating whether dose is a mediator of treatment effect in fluoxetine-randomized trials. Specifically, we investigated whether dose was higher in trials in which the aim was to demonstrate fluoxetine efficacy in comparison with older antidepressants and lower in trials in which the aim was to demonstrate a new drug's efficacy against fluoxetine. METHOD: We applied the model developed by Baron and Kenny to investigate the mediational role of drug dose on treatment effect. We included all randomized controlled trials comparing fluoxetine with other antidepressants as monotherapy in the acute-phase treatment of unipolar major depression. RESULTS: A total of 173 studies were included. In 76 comparisons (44%), fluoxetine was the experimental antidepressant. A metaregression analysis indicated that after adjusting for possible confounders, studies where fluoxetine was the experimental agent were associated with a significant advantage for fluoxetine. However, the Baron and Kenny model revealed no mediational role of drug dose in influencing treatment effect. CONCLUSION: The outcome of fluoxetine-randomized trials changed according to whether this drug was used as a new compound or as a reference. This finding cannot be attributed to antidepressants dose, as dose failed to emerge as mediator of treatment effect in the Baron and Kenny approach.

Psychopharmacological treatment in borderline personality disorder: A pilot observational study in a real-world setting.

Psychotherapy is the cornerstone of treatment for borderline personality disorder (BPD) while pharmacotherapy should be considered only as an adjunctive intervention. In clinical practice, however, most of BPD patients only receive medication. The aim of the study is to first describe pharmacological treatment in BPD patients in Italy and secondly to evaluate if comorbidity or illness severity are associated with the prescription of different class compounds. Data on pharmacological treatment and clinical evaluation of 75 BPD patients were collected in 5 clinical settings. The association between comorbidity and medication was assessed. Moreover, we evaluated the association between pharmacotherapy and severity, defined by a cluster analysis aimed at detecting different groups of patients. Most of the participants (82.7%) were characterized by polypharmacy, with a mean of 2.4 medications per person. Interestingly, the prescription didn't seem to depend on/be based on the severity of the disorder and was only partially determined by the presence of comorbidity. In conclusion, our findings are similar to what described in other clinical studies, supporting the idea that medication management for BPD is only partially coherent with international guidelines. This pilot study confirms the need for more rigorous studies to gain greater understanding of this topic and diminish the gap between guidelines and the real clinical world.

Abnormalities in cortical gray matter density in borderline personality disorder.

BACKGROUND: Borderline personality disorder (BPD) is a chronic condition with a strong impact on patients' affective, cognitive and social functioning. Neuroimaging techniques offer invaluable tools to understand the biological substrate of the disease. We aimed to investigate gray matter alterations over the whole cortex in a group of Borderline Personality Disorder (BPD) patients compared to healthy controls (HC). METHODS: Magnetic resonance-based cortical pattern matching was used to assess cortical gray matter density (GMD) in 26 BPD patients and in their age- and sex-matched HC (age: 38 ± 11; females: 16, 61%). RESULTS: BPD patients showed widespread lower cortical GMD compared to HC (4% difference) with peaks of lower density located in the dorsal frontal cortex, in the orbitofrontal cortex, the anterior and posterior cingulate, the right parietal lobe, the temporal lobe (medial temporal cortex and fusiform gyrus) and in the visual cortex (P<0.005). Our BPD subjects displayed a symmetric distribution of anomalies in the dorsal aspect of the cortical mantle, but a wider involvement of the left hemisphere in the mesial aspect in terms of lower density. A few restricted regions of higher density were detected in the right hemisphere. All regions remained significant after correction for multiple comparisons via permutation testing. CONCLUSIONS: BPD patients feature specific morphology of the cerebral structures involved in cognitive and emotional processing and social cognition/mentalization, consistent with clinical and functional data.