Caregiver depressive symptoms and observed family interaction in low-income children with persistent asthma.

This study examined the relationship between caregiver depressive symptoms and observed parenting behaviors and family processes during interactions among 101 urban, low-income Africtan American families with children with persistent asthma. Caregivers (primarily female) were assessed on four dimensions (i.e., warmth/ involvement, hostility, consistent discipline, relationship quality) in three videotaped interaction tasks (loss, conflict, cohesion). The results indicated that increased depressive symptoms were significantly associated with lower warmth/involvement and synchrony scores and greater hostility scores during the loss and conflict tasks. In the total sample, the highest levels of hostility and the lowest levels of warmth/involvement were found for the conflict task; nevertheless, caregivers with moderate/severe depressive symptoms showed a significantly greater increase in hostility from the loss to the conflict task than caregivers with minimal/mild depressive symptoms. The findings highlight the salience of considering task content in family observational process research to expand our understanding of depressed and nondepressed caregivers abilities to modulate appropriately their behaviors and affect across various family interactions. Implications for improving asthma management for low-income children with persistent asthma are discussed, including the utility of multidisciplinary interventions that combine asthma education with family therapy.

Medication status affects the relationship of symptoms to prepulse inhibition of acoustic startle in schizophrenia.

Inhibition of the acoustic startle response by a smaller preliminary nonstartling stimulus is termed prepulse inhibition (PPI). Schizophrenia patients have impairments in PPI that may not fully normalize even when they are clinically stable on medication, particularly typical antipsychotics. There is evidence that more severe symptoms are associated with more severe PPI abnormalities, but the effect of antipsychotics on this relationship is not clear. Seventy-three male schizophrenia patients underwent acoustic startle and PPI testing. Symptom ratings were performed using the Brief Psychiatric Rating Scale (BPRS) and its subscales. Fifty-two subjects were treated with antipsychotic medication at time of testing; 21 were unmedicated. For all subjects, PPI was negatively correlated with the BPRS psychological discomfort subscale but not with BPRS total symptoms, BPRS positive symptoms or BPRS negative symptoms. For medicated subjects analyzed separately, there were no correlations with BPRS total scores or any subscales. For the unmedicated subjects analyzed separately, there were significant correlations of lower PPI with greater severity of BPRS total symptoms, positive symptoms and the psychological discomfort subscale. These data indicate that more severe symptoms are associated with lower PPI, but that medication status is an important factor in the relationship between symptom severity and sensorimotor gating.

Disruption of sensitization to methylphenidate by a single administration of MK-801.

Blockade of sensitization to methylphenidate by a single injection of MK-801 was investigated using a computerized activity monitoring system. Male Sprague-Dawley rats were housed in test cages and motor activity was recorded continuously for 16 days. After 2 days of baseline recording and a saline injection on day 3, the rats were randomly divided into four experimental groups. All received 2.5 mg/kg of methylphenidate (s.c.) once a day from days 4 to 9, then after five days of no treatment, they were re-challenged with 2.5 mg/kg of methylphenidate on day 15. One group received only methylphenidate, while the other three groups also received a single i.p. injection of MK-801 (0.30 mg/kg) either 24 h (day 3) or 1 h prior to the first of the six methylphenidate injections (day 4), or 1 h prior to the second methylphenidate injection (day 5). A single injection of MK-801 on day 4 (1 h prior to methylphenidate) blocked the development of sensitization to methylphenidate, since a sensitized response could not be elicited six days after cessation of repeated methylphenidate administration (day 15). However, sensitization to methylphenidate still occurred in the groups receiving MK-801 (0.30 mg/kg) on day 5, indicating that the mechanism by which a single injection of MK-801 disrupts sensitization to methylphenidate is sensitive to timing and is not a direct long-term effect. In conclusion, a single injection of MK-801 persistently blocks the development of sensitization to methylphenidate only if it is given with methylphenidate on the first day of the repetitive treatment phase.