Dehydroepiandrosterone Attenuates Cocaine‐Seeking Behaviour Independently of Corticosterone Fluctuations

The neurosteroid dehydroepiandrosterone (DHEA) is involved in the pathophysiology of several psychiatric disorders, including cocaine addiction. We have previously shown that DHEA attenuates cocaine‐seeking behaviour, and also that DHEA decreases corticosterone (CORT) levels in plasma and the prefrontal cortex. Previous studies have found that rats demonstrate cocaine‐seeking behaviour only when the level of CORT reaches a minimum threshold. In the present study, we investigated whether the attenuating effect of DHEA on cocaine seeking is a result of it reducing CORT levels rather than a result of any unique neurosteroid properties. Rats received either daily DHEA injections (2 mg/kg, i.p.) alone, daily DHEA (2 mg/kg, i.p.) with CORT infusion (to maintain stable basal levels of CORT; 15 mg/kg, s.c.) or vehicle (i.p.) as control, throughout self‐administration training and extinction sessions. We found that both DHEA‐treated and DHEA + CORT‐treated groups showed a significantly lower number of active lever presses compared to controls throughout training and extinction sessions, as well as at cocaine‐primed reinstatement. DHEA‐treated rats showed lower CORT levels throughout the experimental phases compared to DHEA + CORT‐treated and control rats. Additionally, we show that DHEA administered to cocaine‐trained rats throughout extinction sessions, or immediately before reinstatement, attenuated cocaine seeking. These findings indicate that DHEA attenuates cocaine‐seeking behaviour independently of fluctuations in CORT levels.     

Suicide Behaviour in the Caribbean

There have been relatively few publications on suicide in the Caribbean. Some of the earliest studies came out of the twin island of Trinidad & Tobago and later on from Guyana and Suriname. It was the ingestion of agro-chemicals by the East Indian population that might have stimulated the interest in those countries. The rate of suicide attempts in the Caribbean has been steadily increasing. Hospital records have confirmed this, but it would appear that in those countries with a high East Indian population that hospitalization has been mainly for ingestion of poisons. In those with a low East Indian population, the Afro-Caribbean has been overdosing with analgesics or benzodiazepines. Those who kill themselves continue to be male in mid-adulthood, but ingestion of agro-chemicals is now far more prevalent than hanging. It is probably because much less preparation is needed for ingestion than for hanging and it is now common knowledge that survival is rare after paraquat ingestion.     

Gambling-Related Beliefs and Gambling Behaviour: Explaining Gambling Problems with the Theory of Planned Behaviour

Investigating how gambling frequency and perceptions towards gambling relate to gambling problems has direct relevance for prevention and treatment programs. Accordingly, this study explored the relationship between a diverse group of gambling beliefs, the intention to gamble, gambling frequency, and gambling problems. To facilitate this, the Theory of Planned Behaviour (TPB) was employed to model the influence of gambling attitudes (e.g., the expected emotional and financial outcomes from gambling), social norms (e.g., perceived approval and gambling behaviour of significant others) and cognitive biases (confidence in the ability to determine the outcome of gambling) on the intention to gamble, gambling frequency, and gambling problems. Two hundred and one volunteers completed a questionnaire that assessed these social-cognitive factors and gambling behaviours. Consistent with expectations, the path analysis revealed the TPB determinants predicted gambling frequency and gambling problems, respectively. Interestingly though, there was the direct path between the intention to gamble and gambling problems, and attitudes and gambling frequency. The potential implications for these findings are discussed.     

Behaviour problems of the mentally retarded.

The behaviour profiles of 176 mentally retarded individuals from two reception centres and nine group homes were assessed. The correlations between behaviour and age, sex, degree of mental retardation, etiology of mental retardation and medical diagnosis were assessed using the Revised Child Behaviour Profile. The severity of behaviour disturbance did not vary with age or medical diagnosis. The moderately retarded subjects presented with more severe behaviour problems, such as aggression, than the severely mentally retarded subjects. The variable most predictive of behavioural problems was etiology of the disorder. Individuals with Down's syndrome had significantly fewer behaviour disturbances and those with autism and pervasive developmental disorder had significantly more behaviour disturbances than other subjects. A psychiatric disorder was found in 10.2% of the sample. The implications of these findings are discussed with respect to public policy.     

Assessment of change with the Developmental Behaviour Checklist

Background The Developmental Behaviour Checklist (DBC) is a 96‐item instrument designed for assessing behavioural and emotional problems among young people with intellectual disability. Methods The present study investigated the validity of the DBC as a measure of change. Changes in individual's DBC scores were correlated with changes in expert clinicians’ ratings of the same subjects. Results A high correlation was found between expert clinician ratings of change in behaviour and change in the total behaviour problem score of the DBC. Conclusions The DBC is able to measure changes in behaviour and emotions which are recognized by an experienced clinician who is following the progress of a child with ID.     

Glutamate Inhibits Ingestive Behaviour

Male rats treated with reserpine were motionless and ingested only a few of ten consecutive intraoral injections of a 1 M solution of sucrose. While injection of apomorphine, a dopamine agonist, stimulated locomotion and stereotyped sniffing in reserpinized rats, it did not reactivate ingestive responses. The non-competitive N-methyl-D-aspartate receptor antagonist MK801, however, stimulated locomotion as well as ingestion suggesting involvement of glutamate in the suppressive effect of resperpine on ingestive responses. A series of experiments was therefore undertaken to investigate the possible physiological role of glutamate in feeding. For this purpose, we used Grill's intraoral intake test, in which the rat is infused intraorally with a sucrose solution and the amount ingested measured. In untreated rats, MK801 dose-dependently facilitated ingestion of the sucrose solution and antagonized inhibition of ingestion by cholecystokinin octapeptide. Administration of cholecystokinin octapeptide or ingestion of sucrose increased the concentration of glutamate in the nucleus of the solitary tract, a brain stem relay transmitting sensory information from the gastrointestinal tract to the forebrain. MK801 was found to bind specifically to this brain area and block the elevation of glutamate and dopamine levels which occurred after treatment with cholecystokinin octapeptide in this neural site. Together these data suggest that dopamine and glutamate may interact within the nucleus of the solitary tract in controlling ingestive behaviour.     

Validity and reliability of the Dysfunctional Behaviour Rating Instrument

The objective of this study was to examine the reliability and validity of the Dysfunctional Behaviour Rating Instrument (DBRI) in cognitively impaired older adults living in the community. A total of 184 adults with suspected cognitive impairment received a standardized history, physical examination and work-up that included the Standardized Mini-Mental State Examination. Caregivers scored a DBRI Behaviour Problem Checklist (BPC) and Lawton Scale for each patient. The reliability of the DBRI, measured by an intraclass correlation coefficient, was 0.75. The correlation coefficient between the DBRI and the BPC total score was 0.71. The correlations between the DBRI and the cognitive, activities of daily living and self-care domain scores of the BPC were lower (0.66, 0.38 and 0.26 respectively). The DBRI is a specific, reliable and valid caregiver-reported measure of dysfunctional behaviour in cognitively impaired elderly living in the community.     

Behaviour of Medial Rectus Motoneurons in the Alert Cat

The activity of identified medial rectus motoneurons was recorded in alert cats during spontaneous and vestibular induced eye movements. Medial rectus motoneurons fired a burst of spikes slightly preceding adducting saccades and increased their discharge rate linearly with successive eye positions in the adducting direction. Conduction velocity (21.3 - 98.2 m/s), eye position sensitivity (ks, 7.1 +/- 1.5 spikes/s/deg), and eye velocity sensitivity (rs, 1 +/- 0.2 spikes/s/deg/s) during spontaneous eye movements, and time constants calculated from phase lead analysis (To, 135 +/- 36 ms) showed values similar to those described previously for cat abducens motoneurons. The firing rate during repeated fixation of the same eye position was affected significantly by the direction of the preceding saccade and by the animal's level of alertness. Eye velocity sensitivity was not significantly affected by changes in the animal's level of alertness. A weak negative relationship (coefficient of correlation=-0.56) was observed between eye velocity sensitivity (rv) and sinusoidal rotational frequency, with no change in eye position sensitivity (kv) with stimulus frequency. The subsequent changes in the time constant (Tv) calculated as Tv=rv/kv in relation to stimulus frequency suggests that the oculomotor system deviates from a (linear) first-order model.     

Evaluation of Behavioural Management in Schools: A Review of the Behaviour Improvement Programme and the Role of Behaviour and Education Support Teams

This paper considers the implementation and impact in schools of the Behaviour Improvement Programme (BIP) and the role within it of Behaviour and Education Support Teams (BESTs). It sets out the background to the introduction of the programme, describes how it was implemented and evaluated, considers its impact on behaviour, attendance and exclusions, and outlines the factors that contributed towards its effectiveness. The specific role and activities of BESTs are described and the nature of their work with pupils, parents, teachers and schools. The difficulties that they experienced are described and factors contributing to effective working.