Neonatal hypoxia-ischemia induces attention-deficit hyperactivity disorder-like behavior in rats.

Attention-deficit hyperactivity disorder (ADHD) may be caused by genetic or environmental factors. Among environmental factors, perinatal complications are related, such as neonatal hypoxia-ischemia (HI). Thus, the aim of this study was to investigate whether HI contributes to the development of characteristics related to ADHD in adult rats, and to correlate the behavioral results with brain damage volume. Male Wistar rats were divided into 2 groups: HI and control. The HI procedure consisted of a permanent occlusion of the right common carotid artery followed by a period of hypoxia (90 min; 8% O2 and 92% N2) on the 7th postnatal day. Two months later, animals were evaluated in the open field test during a single 5-min session, and in the 5-choice serial reaction time task (5-CSRTT), over 25 weeks. Our results demonstrated that animals submitted to HI manifest cognitive impairments in task acquisition, deficits in sustained attention, and increases in impulsivity and compulsivity in response to task manipulation in the 5-CSRTT. Locomotor activity observed in open field did not differ between groups. Moreover, brain volume loss in the total hemisphere, cerebral cortex, white matter, hippocampus, and striatum were observed in HI animals, especially on the side ipsilateral to the lesion. From these results, we can infer that neonatal HI is an environmental factor that could contribute to the development of behavioral characteristics observed in ADHD that are associated with general brain atrophy.

Attentional bias modification in smokers trying to quit: a longitudinal study about the effects of number of sessions.

Attentional bias modification (ABM) to avoid smoking-related cues is a potentially new intervention in addition to existing therapy to stop smoking. We examined immediate and long-term changes in attentional bias and treatment outcomes from multiple ABM sessions in 67 smokers trying to quit. After assessing attentional bias baseline, participants were randomly allocated to one of three training groups: three sessions of ABM (avoid 3); two sessions of placebo-ABM and one session of ABM (avoid 1); and three sessions of placebo-ABM (avoid 0). At baseline, all groups had similar positive attentional bias, which became negative at 24h post-training. After 1 month, avoid 1 and avoid 3 still exhibited negative attentional biases. Only avoid 3 maintained this effect at 6-month, but not at 12-month assessments. ABM produced a long-lasting automatic and maintained avoidance to smoking-related cues which depended on number of sessions; however its effects on treatment outcomes are uncertain.