Adaptation of the Mullen Scales of Early Learning for use among infants aged 5- to 24-months in rural Gambia.

Infants in low-resource settings are at heightened risk for compromised cognitive development due to a multitude of environmental insults in their surroundings. However, the onset of adverse outcomes and trajectory of cognitive development in these settings is not well understood. The aims of the present study were to adapt the Mullen Scales of Early Learning (MSEL) for use with infants in a rural area of The Gambia, to examine cognitive development in the first 24-months of life and to assess the association between cognitive performance and physical growth. In Phase 1 of this study, the adapted MSEL was tested on 52 infants aged 9- to 24-months (some of whom were tested longitudinally at two time points). Further optimization and training were undertaken and Phase 2 of the study was conducted, where the original measures were administered to 119 newly recruited infants aged 5- to 24-months. Infant length, weight and head circumference were measured concurrently in both phases. Participants from both phases were split into age categories of 5-9 m (N = 32), 10-14 m (N = 92), 15-19 m (N = 53) and 20-24 m (N = 43) and performance was compared across age groups. From the ages of 10-14 m, Gambian infants obtained lower MSEL scores than US norms. Performance decreased with age and was lowest in the 20-24 m old group. Differential onsets of reduced performance were observed in the individual MSEL domains, with declines in visual perception and motor performance detected as early as at 10-14 months, while reduced language scores became evident after 15-19 months of age. Performance on the MSEL was significantly associated with measures of growth.

Reduced orbitofrontal and temporal grey matter in a community sample of maltreated children.

BACKGROUND: Childhood maltreatment is strongly associated with increased risk of psychiatric disorder. Previous neuroimaging studies have reported atypical neural structure in the orbitofrontal cortex, temporal lobe, amygdala, hippocampus and cerebellum in maltreated samples. It has been hypothesised that these structural differences may relate to increased psychiatric vulnerability. However, previous studies have typically recruited clinical samples with concurrent psychiatric disorders, or have poorly characterised the range of maltreatment experiences and levels of concurrent anxiety or depression, limiting the interpretation of the observed structural differences. METHODS: We used voxel-based morphometry to compare grey matter volume in a group of 18 children (mean age 12.01 years, SD = 1.4), referred to community social services, with documented and well-characterised experiences of maltreatment at home and a group of 20 nonmaltreated children (mean age 12.6 years, SD = 1.3). Both groups were comparable on age, gender, cognitive ability, ethnicity and levels of anxiety, depression and posttraumatic stress symptoms. We examined five a priori regions of interest: the prefrontal cortex, temporal lobes, amygdala, hippocampus and cerebellum. RESULTS: Maltreated children, compared to nonmaltreated peers, presented with reduced grey matter in the medial orbitofrontal cortex and the left middle temporal gyrus. CONCLUSIONS: The medial orbitofrontal cortex and the middle temporal gyrus have been implicated in reinforcement-based decision-making, emotion regulation and autobiographical memory, processes that are impaired in a number of psychiatric disorders associated with maltreatment. We speculate that grey matter disturbance in these regions in a community sample of maltreated children may represent a latent neurobiological risk factor for later psychopathology and heightened risk taking.