The Shifting Subtypes of ADHD: Classification Depends on How Symptom Reports are Combined

Research on the correlates of ADHD subtypes has yielded inconsistent findings, perhaps because the procedures used to define subtypes vary across studies. We examined this possibility by investigating whether the ADHD subtype distribution in a community sample was sensitive to different methods for combining informant data. We conducted a study to screen all children in grades 1-5 (N = 7847) in a North Carolina County for ADHD. Teachers completed a DSM-IV behavior rating scale and parents completed a structured telephone interview. We found substantial differences in the distribution of ADHD subtypes depending on whether one or both sources were used to define the subtypes. When parent and teacher data were combined, the procedures used substantially influenced subtype distribution. We conclude the ADHD subtype distribution is sensitive to how symptom information is combined and that standardization of the subtyping process is required to advance our understanding of the correlates of different ADHD subtypes.     

CSF 5-HIAA Predicts Suicide Risk After Attempted Suicide

Suicide risk after attempted suicide, as predicted by cerebrospinal fluid (CSF) monoamine metabolite concentrations, was studied in a sample of 92 psychiatric mood disorder inpatients admitted shortly after attempting suicide. The potential of the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the CSF to predict suicide risk within the first year after attempted suicide was studied by means of survival analysis after median split sub-grouping. Eleven patients (12%) committed suicide within 1 year after attempted suicide. Eight of these belonged to the below-the-median (< 87 nM) CSF 5-HIAA subgroup, that is, the suicide risk was 17% as compared with 7% among those with above-the-median CSF 5-HIAA. The cumulative number of survived patient-months during the first year after attempted suicide was significantly lower in the low CSF 5-HIAA subgroup. It was concluded that low CSF 5-HIAA predicts short-range suicide risk after attempted suicide in mood disorder psychiatric inpatients. These findings lend further support to the serotonin hypothesis of suicide risk.     

Sex differences in childhood sexual abuse and suicide-related behaviors

Child sexual abuse and suicide-related behaviors are associated, but it remains unclear if the strength of this association differs in boys and girls. In a systematic review of this association in children and youth, we identified 16 relevant studies, all cross-sectional surveys of students. The association is stronger in boys specific to suicide attempt(s). Adjustments for potential confounding variables explained some, but not all of this sex difference. While additional research would strengthen causal inferences, this sex difference may be influenced by the nature and timing of child sexual abuse as well as the sex of the perpetrator, which in turn shapes the disclosure of these events.     

Serum Lipids in Suicide Attempters

As other studies have shown possible associations of low serum cholesterol concentrations as well as serotonin and corticosteroid deviances with suicide or depression, the present study was undertaken to investigate the serum lipid levels in subgroups of suicide attempters. Serum lipids were determined in 72 suicide attempters. Cerebrospinal fluid monoamine metabolites and plasma cortisol levels were measured, and dexamethasone suppression tests were performed. Hopelessness and suicidality were rated by the Hopelessness Scale (HS) and the Suicidal Intent Scales (SIS). The mean total serum cholesterol (TSC) level was 5.0 ± 1.2 mmol/L. We found no significant correlations between TSC and the monoamine metabolites. High-density lipoprotein cholesterol showed positive correlations with the dopamine metabolite homovanillic acid (r = 0.39, p = 0.04) and the serotonin metabolite 5-hydroxyindoleacetic acid (r = 0.34, p = 0.07). The SIS and HS scales did not correlate significantly with serum lipids. “Violent” attempters showed somewhat higher serum lipid levels than “nonviolent” attempters. We found no significant differences in serum lipid levels between the diagnostic subgroups. Hence, we could not find much support for the hypothesis of associations between low cholesterol levels and decreased serotonin activity in the brain. However, this field merits further investigation.     

Psychosocial and pharmacological treatment of patients following deliberate self-harm: the methodological issues involved in evaluating effectiveness.

Development of effective treatments for patients following deliberate self-harm (self-poisoning or self-injury) is a very important element in suicide prevention. The randomized controlled trial (RCT) is the mainstay of evaluation of treatments. In a systematic review of the literature, the effectiveness of treatments based on RCTs was examined and the quality of the RCTs was assessed. Twenty trials were identified, and where possible, these were grouped on the basis of similarities among the types of treatment. In this paper, we examine the methodological aspects of the trials and consider what may be learned that will assist in the design of future studies in this field. The methodological quality of the trials was reasonable, but most trials included too few participants to detect clinically important differences in rates of repeated self-harm. In planning future trials, the following major issues should be addressed: investigators should perform power calculations to determine the number of subjects necessary to detect clinically important effects, provide information on method of randomization and interventions, use standard measures of outcome, and focus on homogeneous subgroups of patients. Improving the methodology of future studies in this field will be essential if sound evidence is to be obtained which can inform effective service provision for deliberate self-harm patients.