The differential optomotor response of the four-eyed fish Anableps anableps.

The perception of motion is important for the survival and reproduction of many animals, including fish. In the laboratory, support for this idea comes from the observation that many fish show a tendency to follow a series of stripes revolving around a circular aquarium. This response, known as the optomotor response (OMR), is recognized as an innate behavior in many species. The 'four-eyed' fishes of the genus Anableps are an unusual fish from Central and South America and actually have only two eyes. Each eye is divided into upper and lower halves internally and externally. This peculiar dual visual system allows Anableps to feed on creatures that swim or land near or on the water surface or to flee from flying predators attacking from above. It was hypothesized that Anableps should also possess the OMR. We used the OMR as a test to investigate potential differential visual processing in Anableps on normal and 'blinded' fish (the eyes are actually covered--not physically blinded). It was found that the OMR does exist in Anableps and that the strength of this response is dependent on the visual field being tested--a stronger OMR was seen as a result of visual stimulation from the aerial environment.     

Alcohol Consumption and Nearly Lethal Suicide Attempts

W e conducted a case‐control study of the association between nearly lethal suicide attempts and facets of alcohol consumption; namely, drinking frequency, drinking quantity, binge drinking, alcoholism, drinking within 3 hours of suicide attempt, and age began drinking. Subjects were 13–34 years of age. In bivariable analyses, all measures were associated with nearly lethal suicide attempts. Odds ratios ranged from 2.4 for alcoholism to 7.0 for drinking within 3 hours of attempt. All exposure variables except age began drinking exhibited a J‐shaped relationship between alcohol exposure and nearly lethal suicide attempt. After controlling for potential confounders and other measures of alcohol exposure, drinking within 3 hours of attempt remained most strongly (odds ratios > 6) associated. Alcoholism remained significantly associated in most models, but at lower strength.     

Suicide Prevention from a Public Health Perspective

The public health approach to health problems provides a strong framework and rationale for developing and implementing suicide prevention programs. This approach consists of health-event surveillance to describe the problem, epidemiologic analysis to identify risk factors, the design and evaluation of interventions, and the implementation of prevention programs. The application of each of these components to suicide prevention is reviewed. Suggestions for improving surveillance include encouraging the use of appropriate coding, reviewing suicide statistics at the local level, collecting more etiologically useful information, and placing greater emphasis on analysis of morbidity data. For epidemiologic analysis, greater use could be made of observational studies, and uniform definitions and measures should be developed and adopted. Efforts to develop interventions must include evaluating both the process and the outcome. Finally, community suicide prevention programs should include more than one strategy and, where appropriate, should be strongly linked with the community's mental health resources. With adequate planning, coordination, and resources, and the public health approach can help reduce the emotional and economic costs imposed on society by suicide and suicidal behavior.     

Medical Conditions and Nearly Lethal Suicide Attempts

P hysical illness has been studied as a risk factor for suicidal behavior, but little is known about this relationship among younger persons. We conducted a population‐based, case‐control study in Houston, Texas, from November 1992 through September 1995. The final sample consisted of 153 case‐ and 513 control‐subjects aged 13 to 34 years. Case patients were identified at hospital emergency departments and met criteria for a nearly lethal suicide attempt. Control subjects were recruited via a random‐digit‐dial telephone survey. Case patients were more likely than controls to report having any serious medical conditions (crude OR = 3.23; 95% CI = 2.12–4.91). After controlling for age, race/ethnicity, alcoholism, depression, and hopelessness, the adjusted odds ratio for men was 4.76 (95% CI = 1.87–12.17), whereas the adjusted odds ratio for women was 1.60 (95% CI‐0.62–4.17), suggesting that young men with medical conditions are at increased risk for nearly lethal suicide attempts. Increased efforts to identify and appropriately refer these patients are needed.