Rat behavior and dopamine release are modulated by conspecific distress.

Rats exhibit 'empathy' making them a model to understand the neural underpinnings of such behavior. We show data consistent with these findings, but also that behavior and dopamine (DA) release reflects subjective rather than objective evaluation of appetitive and aversive events that occur to another. We recorded DA release in two paradigms: one that involved cues predictive of unavoidable shock to the conspecific and another that allowed the rat to refrain from reward when there were harmful consequences to the conspecific. Behavior and DA reflected pro-social interactions in that DA suppression was reduced during cues that predicted shock in the presence of the conspecific and that DA release observed on self-avoidance trials was present when the conspecific was spared. However, DA also increased when the conspecific was shocked instead of the recording rat and DA release during conspecific avoidance trials was lower than when the rat avoided shock for itself.

Do Antidepressants Induce Psychosis in Children and Adolescents? A Naturalistic Study in Ambulatory Pediatric Population.

OBJECTIVE: The aim of the present study was to examine if selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) induce psychotic symptoms in children and adolescent outpatients. We secondarily aimed to assess the occurrence of adverse events (AE), with particular interest in psychiatric adverse events (PAE), timing of their onset, and the effectiveness of antidepressants in children and adolescents. METHODS: We retrospectively evaluated the computerized medical records of children and adolescents treated with antidepressants (SSRIs or SNRIs) for depressive disorders, anxiety disorders, and obsessive-compulsive disorders. AE and Clinical Global Impressions scores were recorded. RESULTS: Sixty-nine children and adolescents aged 13.3 ± 3.0 years were included. None of the patients treated presented with acute psychotic symptoms (delusions, hallucinations, and disorganized thinking or behavior). Duration of treatment extended over 13.4 ± 11.8 months. PAE occurred in 39% of cases. Of these, 16% included suicidality (ideations or attempts), and 3% included nonpsychotic hypomanic symptoms. Significant clinical improvement was achieved in 41% of patients. CONCLUSIONS: In contrast to the clinical impression of some clinicians, antidepressant treatment in pediatric ambulatory population was not associated with emergence of psychotic symptoms.