Cocaine abuse and adult attention deficit disorder

Cocaine increases dopaminergic tone in the central nervous system, and hyperprolactinemia has been found in chronic cocaine abusers. Dopamine depletion is believed to result from chronic cocaine abuse. Dopamine deficiency has also been associated with attention deficit disorder (ADD) in adults, and dopamine agonists have been effective in the treatment of ADD. Four case reports of cocaine addiction and ADD are presented. ADD was assumed to play an etiologic role in cocaine abuse, and it was postulated that the patients might in part have been self-medicating a dopamine-deficient state. In addition, cocaine addicts without a premorbid history of ADD may experience a temporary cocaine-induced ADD state. In both cases, the dopamine agonist bromocriptine was highly effective for treating ADD and promoting cocaine abstinence. Restoration of the presumed dopamine deficit may permit an easier course of rehabilitation by improving the patient's ability to participate in therapeutic programs.     

Frontiers between attention deficit hyperactivity disorder and bipolar disorder

The co-occurrence of attention deficit hyperactivity disorder (ADHD) and bipolar disorder has received much recent attention in the literature. The authors review the literature examining associations between ADHD and bipolar disorder in children, and data concerning severe irritability in youth with ADHD. This article focuses on (1) population-based studies examining ADHD and bipolar disorder or ADHD and co-occurring irritability, (2) the co-occurrence and prospective relationships of ADHD and bipolar disorder in clinical samples, (3) phenomenology and assessment of bipolar disorder and ADHD, (4) treatment of comorbid ADHD and bipolar disorder, (5) family and genetic studies of ADHD and bipolar disorder, and (6) pathophysiologic comparisons between children with ADHD and irritability and bipolar disorder. We draw on the research to make clinical recommendations and highlight important directions for future research.     

Familial links between attention deficit hyperactivity disorder, conduct disorder, and bipolar disorder

Although family, twin, and adoption studies indicate that attention deficit hyperactivity disorder (ADHD) is a familial condition with a robust genetic component, molecular genetic studies of candidate genes have produced inconsistent findings. One of the challenges to elucidating the genetic architecture of ADHD is its potential genetic heterogeneity. Therefore, efforts are needed to identify etiologically homogenous subgroups of subjects with ADHD for use in genetic studies. The current article reviews evidence suggesting that parsing ADHD subjects based on comorbidity with conduct and bipolar disorders may yield familial subtypes that are suitable for genetic analyses.     

Comorbidity of attention deficit hyperactivity disorder in juvenile bipolar disorder

OBJECTIVE: There is some evidence to suggest that attention deficit hyperactivity disorder (ADHD) and juvenile bipolar disorder could be related. This is based on studies of comorbidity and some preliminary family study data. However, doubts continue to be raised about the relationship between the two disorders. This study examined the comorbidity of disruptive behavior disorders (DBD) that include ADHD, oppositional defiant disorder (ODD) and conduct disorder (CD) in juvenile bipolar disorder. METHOD: Seventy-three subjects with onset of bipolar disorder at age 18 years or younger were evaluated using structured interviews (Missouri Assessment of Genetics Interview for Children, Structured Clinical Interview for DSM-IV Axis I disorders--Clinician Version, and Operational Criteria Checklist for Psychotic Disorders version 3.4). Information was collected from subjects as well as from their parents. Patients with comorbid DBD were compared with patients without DBD. RESULTS: Ten subjects (14%) had one or more comorbid DBD. ADHD, CD, and ODD were present in three (4%), two (3%), and eight (11%) subjects, respectively. Those with DBD had earlier onset of bipolar disorder and spent more time ill compared to those without DBD. CONCLUSIONS: The rates of comorbid DBD in juvenile bipolar disorder are low. The study does not support a definite relationship between ADHD and juvenile bipolar disorder. Higher rates reported previously may be due to differing methods of subject ascertainment. Samples recruited from community and general psychiatric settings may help to clarify the relationship between bipolar disorder and ADHD.     

Comorbidity of attention deficit hyperactivity disorder with early- and late-onset bipolar disorder

OBJECTIVE: The relationship between attention deficit hyperactivity disorder (ADHD) and earlier age at onset of affective illness was examined in probands with a history of bipolar disorder. METHOD: The authors assessed 56 adult bipolar subjects. Those with a history of childhood ADHD (N=8) were age and sex matched with bipolar subjects without a history of childhood ADHD (N=8). RESULTS: The age at onset of the first affective episode was lower for the subjects with bipolar disorder and a history of childhood ADHD (mean=12.1 years, SD=4.6) than for those without a history of childhood ADHD (mean=20. 0 years, SD=11.3). CONCLUSIONS: ADHD in children of bipolar probands might identify children at highest risk for development of bipolar disorder.     

Neural correlates of response inhibition in pediatric bipolar disorder and attention deficit hyperactivity disorder

Impulsivity, inattention and poor behavioral inhibition are common deficits in pediatric bipolar disorder (PBD) and attention deficit hyperactivity disorder (ADHD). This study aimed to identify similarities and differences in the neural substrate of response inhibition deficits that are associated with these disorders. A functional magnetic resonance imaging (fMRI) study was conducted on 15 unmedicated PBD patients (Type I, manic/mixed), 11 unmedicated ADHD patients, and 15 healthy controls (HC) (mean age = 13.5 years; S.D. = 3.5). A response inhibition task examined the ability to inhibit a motor response to a target when a stop cue appeared shortly after. The PBD and ADHD groups did not differ on behavioral performance, although both groups were less accurate than the HC group. fMRI findings showed that for trials requiring response inhibition, the ADHD group, relative to the PBD and HC groups, demonstrated reduced activation in both ventrolateral (VLPFC) and dorsolateral (DLPFC) prefrontal cortex, and increased bilateral caudate activation compared with HC. The PBD group, relative to HC, showed decreased activation in the left VLPFC, at the junction of the inferior and middle frontal gyri, and in the right anterior cingulate cortex (ACC). Prefrontal dysfunction was observed in both the ADHD and PBD groups relative to HC, although it was more extensive and accompanied by subcortical overactivity in ADHD.     

Gabapentin and methylphenidate treatment of a preadolescent with attention deficit hyperactivity disorder and bipolar disorder

Gabapentin is an anticonvulsant drug released in the United States in 1993 for use as adjunctive therapy in refractory partial epilepsy. The mechanism of action of gabapentin is unknown, but the drug has very favorable pharmacokinetics and a good safety profile, which allows its use in high-risk patients. Several reports have described the successful use of gabapentin for bipolar disorders in adults, but there are no controlled studies in the use of gabapentin in children and adolescents. We describe a 12-year-old boy with a history of attention deficient hyperactivity disorder (ADHD), reading disorder, mixed receptive and expressive language disorder, encopresis, and bipolar disorder II who was treated with gabapentin 200 mg/day added to methylphenidate 30 mg/day. Within 3 weeks the improvement and stabilization of mood symptoms was remarkable, as noted by mother, teacher, and clinician, and remained so for 6 months of follow-up. Comorbid bipolar disorder and ADHD is a hotly debated topic in the child and adolescent psychiatric literature, with rates of comorbid ADHD and bipolar disorder ranging from 22% to 90%. Controlled studies are needed to evaluate the possible antimanic mood stabilizing and/or antidepressant properties or gabapentin in youths.     

Genes and attention deficit hyperactivity disorder

The initial molecular genetic studies of attention deficit hyperactivity disorder (ADHD) evaluated two candidate genes (DAT and DRD4) suggested by dopamine theories of this common disorder and its treatment with stimulant medication. The initial reports of weak associations with ADHD have been replicated by many (but not all) investigators, as is expected for genes with small effects. This literature is reviewed, along with emerging literature generated by active research groups investigating additional genes that might contribute to the genetic basis of this complex disorder.     

Schizotypy, attention deficit hyperactivity disorder, and dopamine genes

Previous research has suggested that there may be overlap between schizophrenia and attention-deficit hyperactivity disorder (ADHD). The relationship between schizotypal personality traits, ADHD features and polymorphisms was evaluated in dopamine-related genes. Thirty-one healthy, Caucasian men completed the Rust Inventory of Schizotypal Cognitions (RISC) and the ADHD Self-Report Scale (ASRS). Catechol-O-methyltransferase (COMT) Val158Met, dopamine receptors of the D3 type (DRD3) Ser9Gly, DRD4 variable number of tandem repeats (VNTR), and SLC6A3 VNTR polymorphisms were analyzed. RISC score was correlated with ASRS score (r = 0.54, P = 0.003). COMT Met homozygotes had higher ASRS scores than Val homozygotes (P = 0.005). These findings are consistent with evidence of overlap between schizophrenia and ADHD and support an involvement of COMT genotype in ADHD features.     

Substance abuse in bipolar disorder

Background: High rates of substance abuse have been reported in the general population, with males more often affected than females. Although high rates of substance abuse have also been reported in bipolar patients, the relationship between substance abuse and bipolar disorder has not been well characterized.

Methods: Substance abuse histories were obtained in 392 patients hospitalized for manic or mixed episodes of bipolar disorder and rates of current and lifetime abuse calculated. Analyses comparing sex, subtype (manic vs. mixed) and clinical history variables were conducted.

Results: Rates of lifetime substance abuse were high for both alcohol (48.5%) and drugs (43.9%). Nearly 60% of the cohort had a history of some lifetime substance abuse. Males had higher rates of abuse than females, but no differences in substance abuse were observed between subjects in manic and mixed bipolar states. Rates of active substance abuse were lower in older age cohorts. Subjects with a comorbid diagnosis of lifetime substance abuse had more psychiatric hospitalizations.

Conclusions: Substance abuse is a major comorbidity in bipolar patients. Although rates decrease in older age groups, substance abuse is still present at clinically important rates in the elderly. Bipolar patients with comorbid substance abuse may have a more severe course. These data underscore the significance of recognition and treatment of substance abuse in bipolar disorder patients.     

Sustained attention in sensory modulation disorder and attention deficit/hyperactivity disorder

BackgroundThere are high comorbidity rates between sensory modulation disorder (SMD) and attention deficit hyperactivity disorder (ADHD). Knowledge regarding the objective neuropsychological differentiation between them is scarce.AimThis study examines the effects of SMD and ADHD on a sustained attention task with and without aversive auditory conditions.MethodSixty six young adult females were tested on the Conjunctive - Continuous Performance Task-Visual (CCPT-V) measuring sustained attention, under two conditions: 1) aversive condition (with the three most aversive sounds chosen by the participant), and 2) non-aversive condition (without sounds).ResultsBoth the SMD and ADHD factors exhibited performance deficits in the sustained attention task. All study participants performed worse on both sustained attention and speed of processing when aversive sounds were present.ConclusionWe conclude that impaired sustained attention cannot differentiate between SMD and ADHD. Hence, these results should be taken under consideration in the assessment process of ADHD vs. SMD.     

Risk for emerging bipolar disorder,variants, and symptoms in children with attention deficit hyperactivity disorder,now grown up

AIM: To determine the prevalence of bipolar disorder (BD) and sub-threshold symptoms in children with attention deficit hyperactivity disorder (ADHD) through 14 years’ follow-up, when participants were between 21-24 years old.METHODS: First, we examined rates of BD type I and II diagnoses in youth participating in the NIMH-funded Multimodal Treatment Study of ADHD (MTA). We used the diagnostic interview schedule for children (DISC), administered to both parents (DISC-P) and youth (DISCY). We compared the MTA study subjects with ADHD (n = 579) to a local normative comparison group (LNCG, n = 289) at 4 different assessment points: 6, 8, 12, and 14 years of follow-ups. To evaluate the bipolar variants, we compared total symptom counts (TSC) of DSM manic and hypomanic symptoms that were generated by DISC in ADHD and LNCG subjects. Then we sub-divided the TSC into pathognomonic manic (PM) and non-specific manic (NSM) symptoms. We compared the PM and NSM in ADHD and LNCG at each assessment point and over time. We also evaluated the irritability as category A2 manic symptom in both groups and over time. Finally, we studied the irritability symptom in correlation with PM and NSM in ADHD and LNCG subjects.RESULTS: DISC-generated BD diagnosis did not differ significantly in rates between ADHD (1.89%) and LNCG 1.38%). Interestingly, no participant met BD diagnosis more than once in the 4 assessment points in 14 years. However, on the symptom level, ADHD subjects reported significantly higher mean TSC scores: ADHD 3.0; LNCG 1.7; P < 0.001. ADHD status was associated with higher mean NSM: ADHD 2.0 vs LNCG 1.1; P < 0.0001. Also, ADHD subjects had higher PM symptoms than LNCG, with PM means over all time points of 1.3 ADHD; 0.9 LNCG; P = 0.0001. Examining both NSM and PM, ADHD status associated with greater NSM than PM. However, Over 14 years, the NSM symptoms declined and changed to PM over time (df 3, 2523; F = 20.1; P < 0.0001). Finally, Irritability (BD DSM criterion-A2) rates were significantly higher in ADHD than LNCG (χ² = 122.2, P < 0.0001), but irritability was associated more strongly with NSM than PM (df 3, 2538; F = 43.2; P < 0.0001).CONCLUSION: Individuals with ADHD do not appear to be at significantly greater risk for developing BD, but do show higher rates of BD symptoms, especially NSM. The greater linkage of irritability to NSM than to PM suggests caution when making BD diagnoses based on irritability alone as one of 2 (A-level) symptoms for BD diagnosis, particularly in view of its frequent presentation with other psychopathologies.     

Multicomponent attention deficits in attention deficit hyperactivity disorder

The aim of this study was to examine the specific aspects of attention, such as selective attention, sustained attention, and short-term memory in children with attention deficit hyperactivity disorder, combined subtype (ADHD-C). A total of 40 children with a diagnosis of ADHD from the 4th edition of the Diagnostic and Statistical Manual, aged 6-11 years old were compared with 40 controls matched for age and gender on a battery of tests. Short-term memory span and attention was measured by Visual Aural Digit Span Test-Revised. Stroop test and the Turkish version of Cancellation Test were used to assess selective and sustained attention, respectively. In order to check for factor structure in two groups on the test scores, principal component analysis was conducted for both groups separately. Relative to the comparison children, children with ADHD showed significant deficits on tests that are related to different aspects of attention. The results are consistent with the theories explaining the biological basis of ADHD by scattered attention networks in the brain, which have reciprocal dynamic interactions. Further comparative studies are needed to elucidate whether the cognitive processes that are known to be assessed by these tests are specific to ADHD.     

Sustained attention deficit in bipolar disorder is not a working memory impairment in disguise

Euthymic patients with bipolar disorder have been reported to show persistent deficits in sustained attention. However, the sustained attention task which was used also placed demands on working memory. Bipolar disorder patients in the euthymic state were therefore compared with healthy controls on two measures of sustained attention with and without a working memory component. Signal detection methodology was applied to the results. Euthymic patients with bipolar disorder were particularly impaired at detecting targets in the sustained attention task without a working memory component. This deficit was still apparent in a sub-group of patients who were not currently receiving lithium medication. By contrast, performance in the sustained attention task involving working memory task was not significantly different in the two groups. Sustained attention deficits apparent during the euthymic period of bipolar disorder cannot be explained in terms of working memory impairment and represents a reduced inherent capacity rather than a change in response bias. Deficits in sustaining attention may help explain the difficulties in psychological and occupational functioning in bipolar disorder patients during remission.     

Gait in attention deficit hyperactivity disorder

Abstract Background Cognitive function and the loading of attention presumably play an important role in gait as well as in fall risk, but previous work has not demonstrated this in any cause-and-effect way. Objectives To gain insight into the relationship between gait and cognitive function, we sought: (1) To compare the gait rhythmicity (stride time variability) of children with attention deficit hyperactivity disorder (ADHD) to controls, (2) To test the hypothesis that dual tasking leads to increased stride-to-stride variability in ADHD, and (3) To test whether pharmacological treatment that relieves ADHD symptoms reduces stride-to-stride variability. Patients and Methods Gait was quantified in children with ADHD and in age-matched healthy controls under single task and dual task conditions on three occasions: off medications (both groups) and, in the ADHD group, after double blinded, randomized administration of methylphenidate (MPH) or placebo. Results At baseline, children with ADHD tended to walk with increased stride-to-stride variability compared to the controls during the single task condition (p = 0.09). During dual task walking, stride time variability was significantly reduced in the children with ADHD (p < 0.004), but not in the controls. In the children with ADHD, the placebo did not significantly affect stride-to-stride variability or the dual tasking response. In contrast, stride time variability was significantly reduced on MPH (p < 0.001) such that dual tasking no longer affected variability. Conclusions The present findings demonstrate alterations in the gait of children with ADHD, support a cause and effect link between cognitive function and gait, and suggest that enhancement of attention abilities may, in certain populations, improve gait rhythmicity.