Familial clustering of psychiatric disorders and low IQ.

BACKGROUND: Although the ICD and DSM differentiate between different psychiatric disorders, these often share symptoms, risk factors, and treatments. This was a population-based, case-control, sibling study examining familial clustering of all psychiatric disorders and low IQ, using data from the Israel Draft-Board Registry on all Jewish adolescents assessed between 1998 and 2014. METHODS: We identified all cases with autism spectrum disorder (ASD, N = 2128), severe intellectual disability (ID, N = 9572), attention-deficit hyperactive disorder (ADHD) (N = 3272), psychotic (N = 7902), mood (N = 9704), anxiety (N = 10 606), personality (N = 24 816), or substance/alcohol abuse (N = 791) disorders, and low IQ (⩾2 SDs below the population mean, N = 31 186). Non-CNS control disorders were adolescents with Type-1 diabetes (N = 2427), hernia (N = 29 558) or hematological malignancies (N = 931). Each case was matched with 10 age-matched controls selected at random from the Draft-Board Registry, with replacement, and for each case and matched controls, we ascertained all full siblings. The main outcome measure was the relative recurrence risk (RRR) of the sibling of a case having the same (within-disorder RRR) or a different (across-disorder RRR) disorder. RESULTS: Within-disorder RRRs were increased for all diagnostic categories, ranging from 11.53 [95% confidence interval (CI): 9.23-14.40] for ASD to 2.93 (95% CI: 2.80-3.07) for personality disorders. The median across-disorder RRR between any pair of psychiatric disorders was 2.16 (95% CI: 1.45-2.43); the median RRR between low IQ and any psychiatric disorder was 1.37 (95% CI: 0.93-1.98). There was no consistent increase in across-disorder RRRs between the non-CNS disorders and psychiatric disorders and/or low IQ. CONCLUSION: These large population-based study findings suggest shared etiologies among most psychiatric disorders, and low IQ.

COVID-19 and severe mental illness in Israel: testing, infection, hospitalization, mortality and vaccination rates in a countrywide study.

Previous studies on psychiatric patients infected with COVID-19 have reported a more severe course of disease and higher rates of mortality compared with the general population. This cohort study linked Israeli national databases including all individuals ever hospitalized for a psychiatric disorder (cases), and COVID-19 testing, infection, hospitalization, mortality, and vaccinations, between March 1st 2020 and March 31st 2021. Cases were 125,273 individuals aged 18 and above ever hospitalized in a psychiatric facility (ICD-10 F10-F69 or F90-F99), compared to the total population, n = 6,143,802. Compared with the total population, cases were less likely to be tested for COVID-19, 51.2% (95% CI: 50.8-51.7) vs 62.3% (95% CI 62.2-62.4) and had lower rates of confirmed COVID infection, 5.9% (95% CI: 5.8-6.1) vs 8.9% (95% CI: 8.9-8.9). Among those infected, risks for COVID-19 hospitalization, COVID-19 attributed mortality and all-cause mortality were higher for cases than the total population, adjusted odds ratios were 2.10; (95% CI: 1.96-2.25), 1.76; (95% CI: 1.54-2.01) and 2.02; (95% CI: 1.80-2.28), respectively. These risks were even higher for cases with non-affective psychotic disorders and bipolar disorder. Age adjusted rates of vaccination were lower in cases, 60.4% (95% CI: 59.9-60.8) vs 74.9% (95% CI: 74.8-75.0) in the total population, and particularly low for cases with non-affective psychotic disorders, 56.9% (95% CI: 56.3-57.6). This study highlights the need to increase testing for COVID-19 in individuals ever hospitalized for a psychiatric disorder, closely monitor those found positive, and to reach out to encourage vaccination.

The Effect of Short-Term Acute Residential Treatment on Psychiatric Rehospitalization.

ABSTRACT: Short-Term Acute Residential Treatment (START) homes, located in the community and operating in noninstitutional atmospheres, seek to reduce rehospitalization. This report investigates whether these homes reduced rates and duration of subsequent inpatient stays in psychiatric hospitals. For 107 patients treated in START homes after psychiatric hospitalization, we compared the number and duration of psychiatric hospitalizations before and after their START stay. We found that, compared with the year before the START stay, in the year after the START stay, patients had fewer episodes of rehospitalization (1.60 [SD = 1.23] vs. 0.63 [SD = 1.05], t[106] = 7.097, p < 0.001) and a briefer accumulative duration of inpatient stays (41.60 days [SD = 49.4] vs. 26.60 days [SD = 53.25], t[106] = -2.32, p < 0.03). This suggests that START homes can reduce rehospitalization rates and should be considered a valid alternative to psychiatric hospitalization.

Personality disorders and cause-specific mortality: a nationwide study of 2 million adolescents.

BACKGROUND: Personality disorders are prevalent in 6-10% of the population, but their risk for cause-specific mortality is unclear. The aim of the study was to assess the association between personality disorders diagnosed in late adolescence and all-cause as well as cause-specific (cardiovascular-related, external-related) mortality. METHODS: We performed a longitudinal study on a historical prospective cohort based on nationwide screening prior to recruitment to the Israeli army. The study participants were 16-19-year-old persons who attended the army screening (medical and cognitive, including screening for psychiatric disorders) between 1967 and 2006. Participants were followed from 1967 till 2011. RESULTS: The study included 2 051 606 subjects, of whom 1 229 252 (59.9%) were men and 822 354 (40.1%) were women, mean age 17.36 years. There were 55 508 (4.5%) men and 8237 (1.0%) women diagnosed with personality disorders. The adjusted hazard ratio (HRs) for coronary, stroke, cardiovascular, external-related causes and all-cause mortality among men with personality disorders were 1.34 (1.03-1.74), 1.82 (1.20-2.76), 1.45 (1.23-1.71), 1.41 (1.30-1.53) and 1.44 (1.36-1.51), respectively. The absolute rate difference for all-cause mortality was 56.07 and 13.19 per 105 person-years among men and women, respectively. Among women with personality disorders, the adjusted HRs for external-related causes and all-cause mortality were 2.74 (1.87-4.00) and 2.01 (1.56-2.58). Associations were already evident within 10 years of follow-up. CONCLUSIONS: Personality disorder in late adolescence is associated with increased risk of cardiovascular, external- and all-cause mortality. Increased cardiovascular mortality is evident before the age of 40 years and may point to the importance of lifestyle education already in youth.

Predicting individual variability in task-evoked brain activity in schizophrenia.

What goes wrong in a schizophrenia patient's brain that makes it so different from a healthy brain? In this study, we tested the hypothesis that the abnormal brain activity in schizophrenia is tightly related to alterations in brain connectivity. Using functional magnetic resonance imaging (fMRI), we demonstrated that both resting-state functional connectivity and brain activity during the well-validated N-back task differed significantly between schizophrenia patients and healthy controls. Nevertheless, using a machine-learning approach we were able to use resting-state functional connectivity measures extracted from healthy controls to accurately predict individual variability in the task-evoked brain activation in the schizophrenia patients. The predictions were highly accurate, sensitive, and specific, offering novel insights regarding the strong coupling between brain connectivity and activity in schizophrenia. On a practical perspective, these findings may allow to generate task activity maps for clinical populations without the need to actually perform any tasks, thereby reducing patients inconvenience while saving time and money.

Can Quetiapine Prolong the Antidepressant Effect of Ketamine?: A 5-Year Follow-up Study.

PURPOSE: Ketamine, a noncompetitive, high-affinity antagonist of the N-methyl-d-aspartate-type glutamate receptor, has a rapid effect in patients with treatment-resistant disorder, but many patients who respond to intravenous ketamine relapse within several days. The objective of this study was to examine the long-term outcome of patients' mood 5 years after ketamine treatment. METHODS: Sixteen electroconvulsive therapy referrals received at least 1 intravenous ketamine treatment in addition to their stable antidepressant medications. Depression was evaluated using the Inventory of Depressive Symptomatology-Clinician-Rated, Hamilton Rating Scales for Depression, and Montgomery-Åsberg Depression Rating Scale. Anxiety was measured using the Hamilton Rating Scale. RESULTS: Of 16 patients treated, 6 achieved complete remission, 3 partially responded, and 7 did not respond. At baseline, all patients were treated with antidepressants, 14 patients were also treated with neuroleptics, of whom 5 patients were treated with quetiapine. The time to relapse in the 5 patients taking quetiapine was significantly longer than in patients who were taking other neuroleptics (965.83 ± 824.68 vs 80.5 ± 114.3, Z = 7.001, P = 0.0001). At the 5-year follow-up, 3 of the patients taking quetiapine maintained their remission. Overall levels of depression and anxiety at all times were improved in comparison to baseline. CONCLUSIONS: Our follow-up results suggest that the combination of quetiapine and ketamine can prolong time to relapse after ketamine treatment in patients with treatment-resistant disorder.

Early adulthood psychiatric diagnoses and the subsequent risk of life-time incarceration: a cohort study.

BACKGROUND: The association between incarceration and psychiatric disorders has been noted. Yet, existing studies are cross-sectional or examine the risk of recidivism, which has limited the predictive validity of psychiatric disorders as a risk factor for incarceration. To overcome this limitation, this study used a prospective cohort to examine whether psychiatric diagnoses in early adulthood predicted incarceration throughout a 30-year follow-up. It tested the association between psychiatric diagnoses with future incarcerations, their number and durations, controlling for education and ethnic status. METHODS: This study merged data from three sources in Israel: a prospective 10-year birth cohort study of young adults aged 25-34, conducted in the 1980s (N = 4914) that included a psychiatric interview; data from the Prison Service, including the cause, number and duration of incarcerations; and from the Vital Statistics Registry on death records. RESULTS: Multivariate analysis showed that substance-use disorders, antisocial personality and lower levels of education predicted future incarceration, their number and maximum duration. The remainder diagnoses were not significantly associated with future incarceration. CONCLUSIONS: Results limited the prediction of future incarcerations to persons diagnosed with substance use and antisocial personality, and do not support an independent predictive association between additional psychiatric diagnoses and future incarceration.

Understanding the association between advanced paternal age and schizophrenia and bipolar disorder.

BACKGROUND: Previous studies reported an association between advanced paternal age at birth and increased risk for schizophrenia and bipolar disorder. While some hypothesize that this association is caused by de-novo mutations in paternal spermatozoa, others cite factors associated with psycho-social characteristics of fathers who have children at a late age. This study aims to test these hypotheses. METHODS: A historical-prospective, population-based cohort study, performed by linking the Israeli Draft Board Registry and the Israeli National Psychiatric Hospitalization Registry (N = 916 439; 4488 with schizophrenia, 883 with bipolar disorder). Odds ratios (OR) and two-sided 95% confidence intervals (CI) were calculated by logistic regression models, using paternal age as predictor and risk for later hospitalizations for schizophrenia or bipolar disorder as outcome measure. Models were first fitted unadjusted, then adjusted for paternal age at birth of the first child. RESULTS: In the unadjusted model, offspring of fathers aged 45 and above at birth had increased risk of schizophrenia (OR = 1.71, 95% CI 1.49-1.99) and bipolar disorder (OR = 1.63, 95% CI 1.16-2.24). However, taking into account paternal age at birth of first child, advanced paternal age was no longer associated with increased risk of schizophrenia (OR = 0.60, 95% CI 0.48-0.79) or bipolar disorder (OR = 1.03, 95% CI 0.56-1.90). CONCLUSIONS: Controlling for paternal age at birth of the first offspring, advanced paternal age does not predict increased risk for schizophrenia or bipolar disorder. These data indicate that the association between advanced paternal age and having an offspring with schizophrenia and bipolar disorder is likely due to psychos-social factors, or common genetic variation associated with delayed initial fatherhood.

Discontinuity in the genetic and environmental causes of the intellectual disability spectrum.

Intellectual disability (ID) occurs in almost 3% of newborns. Despite substantial research, a fundamental question about its origin and links to intelligence (IQ) still remains. ID has been shown to be inherited and has been accepted as the extreme low of the normal IQ distribution. However, ID displays a complex pattern of inheritance. Previously, noninherited rare mutations were shown to contribute to severe ID risk in individual families, but in the majority of cases causes remain unknown. Common variants associated with ID risk in the population have not been systematically established. Here we evaluate the hypothesis, originally proposed almost 1 century ago, that most ID is caused by the same genetic and environmental influences responsible for the normal distribution of IQ, but that severe ID is not. We studied more than 1,000,000 sibling pairs and 9,000 twin pairs assessed for IQ and for the presence of ID. We evaluated whether genetic and environmental influences at the extremes of the distribution are different from those operating in the normal range. Here we show that factors influencing mild ID (lowest 3% of IQ distribution) were similar to those influencing IQ in the normal range. In contrast, the factors influencing severe ID (lowest 0.5% of IQ distribution) differ from those influencing mild ID or IQ scores in the normal range. Taken together, our results suggest that most severe ID is a distinct condition, qualitatively different from the preponderance of ID, which, in turn, represents the low extreme of the normal distribution of intelligence.

A randomized, double-blind, placebo- and risperidone-controlled study on valnoctamide for acute mania.

OBJECTIVES: Mood stabilizers administered for bipolar disorder during pregnancy, such as valproic acid, can increase the risk of congenital anomalies in offspring. Valnoctamide is a valproic acid derivative associated with a decreased risk for congenital abnormalities in animals. The present study evaluated the efficacy and safety of valnoctamide monotherapy, compared to placebo, in the treatment of patients in an acute manic episode. METHODS: A 3-week, double-blind, randomized, placebo- and risperidone-controlled, parallel group trial was conducted on 173 patients in an acute manic episode. Patients were randomized to receive valnoctamide 1500 mg/d (n=71), risperidone 6 mg/d (n=32), or matching placebo (n=70). The primary outcome measure was the change in Young Mania Rating Scale (YMRS) scores. RESULTS: Valnoctamide did not differ significantly from placebo on any of the study endpoints (YMRS, Positive and Negative Syndrome Scale, and the Clinical Global Impression Scale for Bipolar Disorder [CGI-BP] scales; all P>.60). Mixed models for repeated measures showed that risperidone produced significantly more improvement than placebo in the overall bipolar disorder CGI-BP severity scale (P=.036), and the CGI-BP severity scale for mania (P=.021). The Kaplan-Meier survival curve revealed higher all-cause discontinuation rates (mainly due to lack of efficacy) in the valnoctamide group compared to the other study groups (P=.026). Patients with higher valnoctamide plasma levels had a numerically higher YMRS response, but this was not statistically significant. CONCLUSIONS: Valnoctamide was well tolerated at 1500 mg/d but lacked efficacy in the treatment of symptoms in patients with acute mania. Possible differences between the biological mechanisms of action of valproic acid and valnoctamide are discussed.

Applying Transcranial Magnetic Stimulation (TMS) Over the Dorsal Visual Pathway Induces Schizophrenia-like Disruption of Perceptual Closure.

Perceptual closure ability is postulated to depend upon rapid transmission of magnocellular information to prefrontal cortex via the dorsal stream. In contrast, illusory contour processing requires only local interactions within primary and ventral stream visual regions, such as lateral occipital complex. Schizophrenia is associated with deficits in perceptual closure versus illusory contours processing that is hypothesized to reflect impaired magnocellular/dorsal stream. Perceptual closure and illusory contours performance was evaluated in separate groups of 12 healthy volunteers during no TMS, and during repetitive 10 Hz rTMS stimulation over dorsal stream or vertex (TMS-vertex). Perceptual closure and illusory contours were performed in 11 schizophrenia patients, no TMS was applied in these patients. TMS effects were evaluated with repeated measures ANOVA across treatments. rTMS significantly increased perceptual closure identification thresholds, with significant difference between TMS-dorsal stream and no TMS. TMS-dorsal stream also significantly reduced perceptual closure but not illusory contours accuracy. Schizophrenia patients showed increased perceptual closure identification thresholds relative to controls in the no TMS condition, but similar to controls in the TMS-dorsal stream condition. Conclusions of this study are that magnocellular/dorsal stream input is critical for perceptual closure but not illusory contours performance, supporting both trickledown theories of normal perceptual closure function, and magnocellular/dorsal stream theories of visual dysfunction in schizophrenia.

Do implantable cardioverter defibrillators contribute to new depression or anxiety symptoms? A retrospective study.

OBJECTIVE: In this retrospective cross-sectional study, we evaluated the existence of psychiatric symptoms which appeared after implantation of an implantable cardioverter defibrillator (ICD). METHODS: Patients with ICDs were diagnosed using the Mini International Neuropsychiatric Interview (MINI) and were excluded if they had any psychiatric diagnosis prior to ICD implantation. Depression and anxiety were evaluated using the HAM-D and HAM-A rating scales and their attitude towards the ICD using a visual analog scale (VAS). Ninety five ICD patients with mean age of 66 years (±11.5) were recruited, 80 (84%) were men. RESULTS: Four (4%) patients were diagnosed with new-onset MDD and one patient (1%) with anxiety. Twenty seven (28%) were found to have significant depressive symptoms (HAM-D >8), without MDD diagnosis; half of them attributing these symptoms to the device. Seven (8%) patients experienced phantom shocks and had relatively higher depressive scores (HAM-D 10.3 vs. 5.8; F = 3.696; p = 0.058). The MDD rates in our study were rather consistent with those reported for cardiac patients. CONCLUSIONS: We suggest that ICD contributed little, if any, additional depressive or anxiety symptoms after implantation. We found that the overall attitude towards the device was positive and that shocks and phantom shocks were related to depressive symptoms.

Risk of suicide among female adolescents with eating disorders: a longitudinal population-based study.

PURPOSE: Suicide is a major cause of death among individuals with eating disorders. This study examined risk of suicide among females with eating disorders based on population-based military data. METHODS: Data on diagnoses of eating disorders from the pre-induction screening for psychopathology and diagnoses assigned during military service were merged with data on later suicide from the nationwide Israeli Death Registry. We identified 1,356 females with eating disorders and compared their risk of suicide to a population-based control group of females without eating disorders over a mean follow-up period of 8.5 ± 5.34 years. RESULTS: Females with eating disorders had a higher rate of suicide (0.22 %, n = 3) compared to females without eating disorders (0.03 %, n = 166). Having a moderate-severe eating disorder was associated with increased risk of suicide (RR = 12.50, 95 % CI = 3.86-38.09), whereas none of the females diagnosed as having a mild eating disorder died by suicide. CONCLUSIONS: Females with moderate-severe eating disorders are at risk of suicide and should be monitored for suicidal intent.

Allopurinol for mania: a randomized trial of allopurinol versus placebo as add-on treatment to mood stabilizers and/or antipsychotic agents in manic patients with bipolar disorder.

OBJECTIVE: An emerging body of evidence supports a role for dysfunctional purinergic neurotransmission in mood disorders. Adenosine agonists have been shown to have properties similar to those of dopamine antagonists; there is a well-characterized interaction between adenosine and dopamine receptors in the ventral striatum, and increasing adenosinergic transmission has been demonstrated to reduce the affinity of dopamine agonists for dopamine receptors. Allopurinol increases adenosine levels in the brain, and hence is hypothesized to reduce the symptoms of mania. Two randomized, placebo-controlled trials administering add-on allopurinol to manic patients showed significantly greater improvements in Young Mania Rating Scale (YMRS) scores for drug compared to placebo, while a more recent, relatively small, add-on study showed negative results. Based on these data, our objective was to examine the efficacy of allopurinol as add-on treatment to mood stabilizers and/or antipsychotic agents in manic patients with bipolar disorder. METHODS: We performed a large, well-powered, multicenter, six-week, randomized, placebo-controlled trial of allopurinol added to mood stabilizers and/or antipsychotic agents in 180 patients with bipolar disorder in an acute manic episode. RESULTS: Both groups showed improvement on the YMRS (effect size of 1.5 for placebo and 1.6 for allopurinol), with no difference observed between groups on YMRS scores (t = 0.28, p = 0.78). There was no difference in the proportion of patients who responded to treatment (defined as showing at least 50% improvement in YMRS score) between the two groups (p = 0.92), or in dropout rates (p = 0.84). LIMITATIONS: None of our patients received lithium. However, the side effects of lithium and its narrow therapeutic index made the use of lithium less common and, therefore, our study results reflect common current clinical practice. In the present study, we used a variety of antipsychotic and/or mood stabilizing treatments, to which we added allopurinol; one might hypothesize that add-on allopurinol has a different effect in combination with different antipsychotic agents or mood stabilizers. CONCLUSIONS: The findings of this large, well-powered study do not support add-on allopurinol as a treatment for acute mania. This study did not test the efficacy of allopurinol as monotherapy.

Longitudinal association between epilepsy and schizophrenia: a population-based study.

A large number of studies have reported an association between epilepsy and major psychiatric conditions. This study investigated the association between epilepsy and later schizophrenia, utilizing a historical-prospective, population-based design. Of the 861,062 17-year-old male adolescents consecutively screened by the Israeli Draft Board and found free of major mental illness, 0.06% suffered from severe, treatment-refractory epilepsy, 0.25% had treated, controlled epilepsy, and 0.16% had a history of seizures which had abated 5 or more years prior to screening. Hospitalization for schizophrenia was ascertained through the Israeli National Psychiatric Hospitalization Case Registry, with an average follow-up of 9.6±1.0years (range: 1.0-10.0years). Risk of hospitalization was calculated using Cox regression analyses, compared to socioeconomic-adjusted risk of hospitalization in the general population of male adolescents. Among adolescents whose epilepsy was nonresponsive to medication, the adjusted risk of hospitalization was significantly increased for schizophrenia (HR=3.89, 95% CI=1.75-89.67). Male adolescents with successfully treated epilepsy were not at increased risk for schizophrenia. Male adolescents with severe, treatment-refractory epilepsy are at increased risk of later schizophrenia. Future studies attempting to understand the biology of this association might focus on this subset of patients, and these patients should be monitored for the appearance of psychosis.

Aggression-impulsivity, mental pain, and communication difficulties in medically serious and medically non-serious suicide attempters.

BACKGROUND: Unbearable mental pain, depression, and hopelessness have been associated with suicidal behavior in general, while difficulties with social communication and loneliness have been associated with highly lethal suicide attempts in particular. The literature also links aggression and impulsivity with suicidal behavior but raises questions about their influence on the lethality and outcome of the suicide attempt. OBJECTIVES: To evaluate the relative effects of aggression and impulsivity on the lethality of suicide attempts we hypothesized that impulsivity and aggression differentiate between suicide attempters and non-attempters and between medically serious and medically non-serious suicide attempters. METHOD: The study group included 196 participants divided into four groups: 43 medically serious suicide attempters; 49 medically non-serious suicide attempters, 47 psychiatric patients who had never attempted suicide; and 57 healthy control subjects. Data on sociodemographic parameters, clinical history, and details of the suicide attempts were collected. Participants completed a battery of instruments for assessment of aggression-impulsivity, mental pain, and communication difficulties. RESULTS: The medically serious and medically non-serious suicide attempters scored significantly higher than both control groups on mental pain, depression, and hopelessness (p<.001 for all) and on anger-in, anger-out, violence, and impulsivity (p<.05 for all), with no significant difference between the two suicide attempter groups. Medically serious suicide attempters had significantly lower self-disclosure (p<.05) and more schizoid tendencies (p<.001) than the other three groups and significantly more feelings of loneliness than the medically non-serious suicide attempters and nonsuicidal psychiatric patients (p<.05). Analysis of aggression-impulsivity, mental pain, and communication variables with suicide lethality yielded significant correlations for self-disclosure, schizoid tendency, and loneliness. The interaction between mental pain and schizoid traits explained some of the variance in suicide lethality, over and above the contribution of each component alone. CONCLUSIONS: Aggression-impulsivity and mental pain are risk factors for suicide attempts. However, only difficulties in communication differentiate medically serious from medically non-serious suicide attempters. The combination of unbearable mental pain and difficulties in communication has a magnifying effect on the risk of lethal suicidal behavior.

Immediate-release methylphenidate for attention deficit hyperactivity disorder (ADHD) in adults.

BACKGROUND: Symptoms of attention deficit hyperactivity disorder (ADHD), diagnosed mainly in children, often persist into adulthood. Adults in this group have a high rate of other psychiatric problems and functional difficulties in a number of key areas such as academic achievement, interpersonal relationships, and employment. Although the usefulness of immediate-release methylphenidate in children has been extensively studied, studies in adults, which are few, demonstrate varying results. OBJECTIVES: To evaluate the efficacy and tolerability of immediate-release methylphenidate versus placebo in the treatment of adults with ADHD. SEARCH METHODS: We searched the following databases in November 2013: CENTRAL, Ovid MEDLINE, EMBASE, PsycINFO, Database of Abstracts of Reviews of Effects (DARE), and two trials registers. Biosis was searched in December 2013. We inspected references of all relevant papers to identify more studies and contacted authors of recently published trials. SELECTION CRITERIA: We included all randomized trials comparing immediate-release methylphenidate versus placebo in participants aged 18 years or older with ADHD. We excluded trials conducted on subpopulations of adults with ADHD such as adults with both ADHD and substance dependence. DATA COLLECTION AND ANALYSIS: Two review authors independently selected trials, extracted data, and assessed trial risk of bias. We contacted authors of trials to ask for additional and missing data. For dichotomous outcomes, we calculated risk ratios (RRs) and 95% confidence intervals (CIs). For continuous outcomes, we calculated mean differences (MDs) or standardized mean differences (SMDs) with 95% CIs. MAIN RESULTS: Results from the 11 randomized controlled trials (474 participants, counting participants from cross-over studies as a single arm, and counting both arms from parallel studies) included in the review demonstrated improvement in core clinical ADHD symptoms of hyperactivity, impulsivity, and inattentiveness, and overall improvement. We were able to pool results from 10 studies, which included 466 participants.Most included studies were judged to have unclear risk of bias for most categories. However, as all studies were randomized, double-blind, and placebo-controlled and, in general, did not contain factors that significantly decreased the quality of the body of evidence, the quality of evidence was assessed as "high" for most outcomes according to the GRADE (Grades of Recommendation, Assessment, Development, and Evaluation) approach. For one outcome-inattentiveness-most information came from studies at unclear risk of bias, and so the quality of evidence for this outcome was judged as "moderate."Results are given as SMD for each of the core clinical symptoms of ADHD. In all cases, participant numbers were calculated by counting participants in a single arm from cross-over studies and in both arms from parallel studies. The SMD for the outcome of hyperactivity was -0.60 (95% CI -1.11 to -0.09, 6 studies, number of participants (n) = 245, high-quality evidence) in favor of immediate-release methylphenidate; the SMD for impulsivity was -0.62 (95% CI -1.08 to -0.17, 5 studies, n = 207, high-quality evidence) in favor of immediate-release methylphenidate; and the SMD for inattentiveness was -0.66 (95% CI -1.02 to -0.30, 7 studies, n = 391, moderate-quality evidence) in favor of immediate-release methylphenidate. Moderate to extreme statistical heterogeneity was detected for all outcomes. Subgroup analysis comparing high versus low doses did not indicate that higher doses of immediate-release methylphenidate were associated with greater efficacy.For overall change, the SMD was -0.72 (95% CI -1.12 to -0.32, 9 studies, n = 455, high-quality evidence) in favor of immediate-release methylphenidate.The effects of immediate-release methylphenidate on anxiety and depression as parameters of general changes in mental state were equivocal. Some trials reported reduction in depression and anxiety, others detailed no change, and still others described an increase in depressive and anxious symptoms.The most common adverse effect was loss of appetite, in some cases with weight loss. Although no study reported either of these effects as problematic or severe, the included studies were of short duration; thus clinical significance could not be properly assessed. Five studies reported changes in systolic or diastolic blood pressure, and three reported increases in heart rate. None of these results were judged to present cause for concern. No study reported clinically significant adverse effects-cardiovascular or other. Three studies did not mention adverse effects. We were unable to determine whether adverse effects were not discussed by study authors because none occurred, or because no data on adverse effects were collected. AUTHORS' CONCLUSIONS: Data from randomized controlled trials suggest that immediate-release methylphenidate is efficacious for treating adults with ADHD with symptoms of hyperactivity, impulsivity, and inattentiveness, and for improving their overall clinical condition. Trial data suggest that adverse effects from immediate-release methylphenidate for adults with ADHD are not of serious clinical significance, although this conclusion may be limited, certainly in the case of weight loss, by the short duration of published studies.