Internal Validity of the Disruptive Behavior Disorder Symptoms: Implications from Parent Ratings for a Dimensional Approach to Symptom Validity

A dimensional approach was used to evaluate the internal validity of the DSM-III-R ADHD-inattention, ADHD-hyperactivity/impulsivity, oppositional defiant disorder (ODD), and conduct disorder (CD) symptoms (i.e., whether a symptom has a stronger correlation with its own dimension than the other three). Parents rated 4,019 children between the ages of 2 and 19 on these symptoms. The results showed that 5 of the 6 inattention symptoms, 3 of the 4 hyperactivity symptoms, 1 of the 4 impulsivity symptoms, 6 of the 9 oppositional defiant disorder symptoms, and 8 of the 11 CD symptoms had significant internal validity. Confirmatory factor analysis (CFA) found support for inattention, hyperactivity/impulsivity, oppositional defiant, and conduct disorder dimensions. Multiple-group CFA also found support for factor pattern and loading invariance across gender. The implications of these results as well as the merits of the dimensional approach to symptom validity are discussed in the context of the DSM-IV changes in ADHD, ODD, and CD.     

Delay of gratification in psychopathic and nonpsychopathic offenders.

Delay of gratification is a prototypical measure of self-control that merits systematic investigation in psychopaths. White male prisoners were provided with repeated opportunities to select an immediate response with uncertain reward or a delayed response with a higher rate of reward under one of three incentive conditions. Psychopaths' performance depended on their level of trait anxiety and incentive condition: Whereas low-anxious psychopaths were relatively unwilling to delay when omission of expected rewards also incurred monetary punishments, they displayed relatively superior performance when the task involved rewards only. Findings complement those for passive avoidance learning in psychopaths and suggest that inhibitory self-control in low-anxious psychopaths is somewhat impaired under conditions involving a combination of monetary rewards and punishments.     

The use of the MacAndrew Alcoholism Scale in detecting substance abuse and antisocial personality

We evaluated the hypothesis that characterological factors, particularly antisocial personality, influence scores on the MacAndrew Alcoholism Scale (MAC). Using the Washington University research criteria to establish diagnoses, the following subgroups were defined: subjects who received no psychiatric diagnoses; subjects who received diagnoses other than alcoholism, drug dependence, or antisocial personality; and subjects who received a diagnosis of alcoholism, drug dependence, and/or antisocial personality, alone or in combination with other psychiatric diagnoses. The highest MAC scores were obtained by subjects diagnosed as having antisocial personality without alcoholism or drug dependence and subjects diagnosed with antisocial personality, drug dependence, and alcoholism. Alcoholics without antisocial personality or drug dependence, and subjects with other psychiatric diagnoses scored lowest. Although higher MAC scores were obtained by males, MAC scores greater than 24 correctly classified the greatest number of males and females as alcoholic, drug dependent and/or antisocial. These findings are interpreted as consistent with MacAndrew's reinterpretation of the scale as assessing a dimension of personality, rather than solely a tendency to addiction.     

Acquisition and retention of control of instrumental behavior by a cue-signaling airblast: How specific are conditioned anticipations?

The conditioned state evoked by a CS that had been paired with an aversive airblast was assessed by superimposing the CS on baselines of instrumental responding. The first experiment used a shock avoidance baseline; CS-airblast pairings were administered on the baseline, with the shock avoidance schedule in effect. The CS that signaled airblast came, over trails, to accelerate shock avoidance responding. As further CS-airblast trials were administered, however, the acceleratory effect of the CS decreased, producing an inverted-U-shaped acquisition curve. A second experiment used off-baseline CS-airblast conditioning, and the CS was tested on both shock avoidance and water reinforcement baselines. After 20 CS-airblast pairings the CS accelerated shock avoidance and suppressed water-reinforced responding. After 10o pairings, however, the acceleratory effect on shock avoidance was much attenuated, although the suppressions of the water-reinforced behavior did not differ between 20- and 100-trial groups. Two further experiments examined retention, over a 45-day interval, of the attenuation of the CS's effects on shock avoidance. Over the retention interval, this attenuation disappeared. It was, however, reinstated by giving the animals “reminder” presentations of the airblast. These results are interpreted as representing systematic changes in the specificity of the conditioned state evoked by a Pavlovian CS.     

A mask for rabbit stereotaxic gas anesthesia

A mask suitable for delivering gas anesthesia to a rabbit in a stereotaxic headholder is described. The mask allows simple delivery of any volatile anesthesia to the rabbit for long periods during stereotaxic surgery, providing an ideal means for rabbit anesthesia when recovery is important.