Graham D. Burrows

Human Melatonin Suppression by Light is Intensity Dependent

Five intensities of artificial light were examined for the effect on nocturnal melatonin concentrations. Maximum suppression of melatonin following 1 hr of light at midnight was 71%, 67%, 44%, 38%, and 16% with intensities of 3,000, 1,000, 500, 350, and 200 lux (lx), respectively. In contrast to some previous reports, light of 1,000 lx intensity was sufficient to suppress melatonin to near daytime levels, and intensities down to 350 lx were shown to significantly suppress nocturnal melatonin levels below prelight values. On the basis of these data, it is suggested that when examining the melatonin sensitivity of patient groups (such as bipolar affective disorders) to artificial light, an appropriate light intensity should be established in each laboratory. Light of less intensity (e.g., 200–350 lx) may be more suitable to dichotomize patient groups from control subjects.

Posttraumatic stress disorder in response to HIV infection

This study investigated the psychological impact of HIV infection through assessment of posttraumatic stress disorder in response to HIV infection. Sixty-one HIV-positive homosexual/bisexual men were assessed for posttraumatic stress disorder in response to HIV infection (PTSD-HIV) using a modified PTSD module of the DIS-III-R. Thirty percent met criteria for a syndrome of posttraumatic stress disorder in response to HIV diagnosis (PTSD-HIV). In over one-third of the PTSD cases, the disorder had an onset greater than 6 months after initial HIV infection diagnosis. PTSD-HIV was associated with other psychiatric diagnoses, particularly the development of first episodes of major depression after HIV infection diagnosis. PTSD-HIV was significantly associated with a pre-HIV history of PTSD from other causes, and other pre-HIV psychiatric disorders and neuroticism scores, indicating a similarity with findings in studies of PTSD from other causes. The findings from this preliminary study suggest that a PTSD response to HIV diagnosis has clinical validity and requires further investigation in this population and other medically ill groups. The results support the inclusion of the diagnosis of life-threatening illness as a traumatic incident that may lead to a posttraumatic stress disorder, which is consistent with the DSM-IV criteria.

The World Federation of Societies of Biological Psychiatry (WFSBP) Guidelines for the Biological Treatment of Bipolar Disorders, Part III: Maintenance Treatment

Summary As with the two preceding guidelines of this series, these practice guidelines for the pharmacological maintenance treatment of bipolar disorder were developed by an international task force of the World Federation of Societies of Biological Psychiatry (WFSBP). Their purpose is to supply a systematic overview of all scientific evidence relating to maintenance treatment. The data used for these guidelines were extracted from a MEDLINE and EMBASE search, from recent proceedings from key conferences and various national and international treatment guidelines. The scientific justification of support for particular treatments was categorised into four levels of evidence (A-D). As these guidelines are intended for clinical use, the scientific evidence was not only graded, but also reviewed by the experts of the task force to ensure practicality.

Menstrual migraine: a double-blind trial of percutaneous estradiol

The present study investigated whether administration of percutaneous estradiol for the 7 days encompassing menstruation (the paramenstruum) would be effective in alleviating menstrual migraine. The study was a double-blind cross-over placebo comparison of percutaneous estradiol in gel form. Twenty-two women who suffered from regular recurring menstrual migraine were studied during 2 assessment menstrual cycles, 4 treatment cycles (2 of estradiol gel, 2 of placebo gel), and 1 follow-up (no treatment) cycle. Women completed daily records of the occurrence and severity of migraine and medication used. Eighteen women completed the study. There was a significant reduction in the frequency of migraine in the paramenstruum and in the amount of medication taken during use of percutaneous estradiol. Women expressed a significant preference for continuation of therapy with percutaneous estradiol.

The biological basis of anxiety. An overview.

The DSM-III divides anxiety disorders into two broad categories, Phobic Disorders and Anxiety States. Anxiety states characterised by panic attacks have been separated from generalised anxiety disorders. While this classification may not be generally accepted it is of heuristic value. Delineation of panic disorder as a distinct diagnostic entity has led to renewed efforts to identify a biological cause for the sudden severe somatic and psychological symptoms experienced by these patients. A review of evidence for the involvement of the major neurotransmitter systems is presented. Systematic investigations in DSM-III defined groups of patients are only beginning to be reported. It is difficult as yet to draw any definite conclusions, but some tentative evidence for abnormalities of the noradrenergic system and the GABA-benzodiazepine chloride ionophore receptor complex are emerging. The reliable induction of panic attacks by chemical agents provides the promise of a greater understanding of the possible biological mechanisms involved in this anxiety disorder.

Suicidal ideation, suicide attempts, and HIV infection

A cross-sectional study was performed to investigate the prevalence and predictors of suicidal ideation and past suicide attempt in an Australian sample of human immunodeficiency virus (HIV)-positive and HIV-negative homosexual and bisexual men. Sixty-five HIV-negative and 164 HIV-positive men participated. A suicidal ideation score was derived from using five items selected from the Beck Depression Inventory and the General Health Questionnaire (28-item version). Lifetime and current prevalence rates of psychiatric disorder were evaluated with the Diagnostic Interview Schedule Version-III-R. The HIV-positive (Centers for Disease Control and Prevention [CDC] Stage IV) men (n = 85) had significantly higher total suicidal ideation scores than the asymptomatic HIV-positive men (CDC Stage II/III) (n = 79) and the HIV-negative men. High rates of past suicide attempt were detected in the HIV-negative (29%) and HIV-positive men (21%). Factors associated with suicidal ideation included being HIV-positive, the presence of current psychiatric disorder, higher neuroticism scores, external locus of control, and current unemployment. In the HIV-positive group analyzed separately, higher suicidal ideation was discriminated by the adjustment to HIV diagnosis (greater hopelessness and lower fighting spirit), disease factors (greater number of current acquired immunodeficiency syndrome [AIDS]-related conditions), and background variables (neuroticism). Significant predictors of a past attempted suicide were a positive lifetime history of psychiatric disorder (particularly depression diagnoses), a lifetime history of infection drug use, and a family history of suicide attempts. The findings indicate increased levels of suicidal ideation in symptomatic HIV-positive men and highlight the role that multiple psychosocial factors associated with suicidal ideation and attempted suicide play in this population.

Selective effects of acute serotonin and catecholamine depletion on memory in healthy women.

There is converging evidence that brain serotonin and dopamine may selectively modulate learning and memory in humans. However, this has not been directly demonstrated. In the current study, we used the method of amino acid precursor depletion to explore the effects of low serotonin and catecholamine function on memory in healthy female volunteers. Participants completed three experimental sessions: (i) tryptophan depletion (TD to lower 5-HT); (ii) tyrosine and phenylalanine depletion (TPD to lower catecholamines); and (iii) a balanced control condition (Bal). All testing was conducted in a double-blind, placebo-controlled, crossover design. Cognitive and mood assessments were performed at baseline and 5 h after ingesting the amino acid mixture. Consistent with previous studies, TD impaired declarative memory consolidation on a structured word-learning task, while TPD, acting to lower brain dopamine availability, impaired spatial working memory. No secondary deficits were observed on measures of attention, short-term memory or subjective mood state. These findings suggest that low brain serotonin versus dopamine selectively impairs memory performance in humans. This may shed light on the role of these neurotransmitters in disorders that are characterized by significant memory impairment.

Melatonin Sensitivity to Dim White Light in Affective Disorders

Both dim and bright light has been shown to suppress the nocturnal secretion of the pineal hormone melatonin. Early reports suggests that an abnormal response to light occurs in patients with bipolar affective disorder, where as patients with major depressive disorder respond similarly to controls. It has been suggested that this abnormal sensitivity of the melatonin response to light could be a trait marker of bipolar affective disorder. However reports lack consistency. Hence, we investigated the melatonin suppression by dim light (200 lux) in patients with bipolar affective disorder, seasonal affective disorder and major depressive disorder. Results suggest that a supersensitive melatonin suppression to light in bipolar affective disorder (p < .005), and seasonal affective disorder (p < .05), whereas patients with major depressive disorder display similar suppression to controls. The supersensitivity may be a mechanism where by phase-delayed rhythms, are re-synchronised to a new circadian position. Conversely, an abnormality may exist in the pathway from the retina to the suprachiamatic nucleus.

Psychiatric progress: Mood and the menstrual cycle

Abstract A majority of women are aware of menstrual cycle-related changes in mood and behaviour. Psychiatric disorders may also be influenced by the menstrual cycle. A premenstrual tension syndrome has been described. Research into the prevalence, actiology and management of this condition has been hampered by additions and alterations to the original description and methodological difficulties involved in menstrual cycle research. Biological, psychological and socialogical theories have been proposed to explain menstrual cycle-related mood changes. Our own studies have found evidence of ovarian steroid disturbances, and impaired psychological functioning in women with the premenstrual syndrome. Therapeutic approaches must consider both aspects. Medication often makes the patient more accessible and receptive to regimens aimed at increasing coping skills. More vigorous research into this disorder is needed.

Stress and anxiety as factors in the onset of problem gambling : Implications for treatment

Many new and accessible forms of gambling have been introduced in Australia in the last decade, with a concomitant increase in research into gambling behaviour and its treatment. This article reviews the clinical characteristics of gambling and proposes a continuum from social gambling, through problem gambling, to the more severe form of pathological gambling. The role of stress and anxiety as precipitating and perpetuating factors in problem gambling is discussed, highlighted by data on the aetiology of problem gambling from the Addiction Research Institute. The article concludes with a review of treatment implications for problem gambling.