Hypothesis testing is an important activity of empirical research and evidence-based medicine. A well worked up hypothesis is half the answer to the research question. For this, both knowledge of the subject derived from extensive review of the literature and working knowledge of basic statistical concepts are desirable. The present paper discusses the methods of working up a good hypothesis and statistical concepts of hypothesis testing.

Research studies are usually carried out on sample of subjects rather than whole populations. The most challenging aspect of fieldwork is drawing a random sample from the target population to which the results of the study would be generalized. In actual practice, the task is so difficult that some sampling bias occurs in almost all studies to a lesser or greater degree. In order to assess the degree of this bias, the informed reader of medical literature should have some understanding of the population from which the sample was drawn. The ultimate decision on whether the results of a particular study can be generalized to a larger population depends on this understanding. The subsequent deliberations dwell on sampling strategies for different types of research and also a brief description of different sampling methods.

The literature on hallucinations is reviewed, including its occurrence in different psychiatric disorders, neurological disorders and normal persons. The diagnostic significance of hallucinations is also discussed. Reports of hallucinations in normal people are reviewed. The different modes of the management of hallucinations are briefly discussed.

Background:With a rapidly increasing population of older aged people, epidemiological data regarding the prevalence of mental and physical illnesses are urgently required for proper health planning. However, there is a scarcity of such data from India.Aims:To study the frequency and pattern of psychiatric morbidity present and the association of physical illness with psychiatric morbidity in an elderly urban population.Settings and Design:Cross-sectional, epidemiological study.Materials and Methods:All the consenting elderly persons in a municipal ward division (n=202) were enrolled after surveying a total adult population of 7239 people. A door to door survey was undertaken where the participants were interviewed and physically examined. General Health Questionnaire-12, Mini Mental State Examination, CAGE Questionnaire and Geriatric Depression Scale were used in the interview apart from consulting the available documents. Other family members were also interviewed to verify the information.Statistical Analysis:Chi-square test with Yates correction.Results:Psychiatric illnesses were detected in 26.7% while physical illnesses were present in 69.8% of the population surveyed. Predominant psychiatric diagnoses were depressive disorders, dementia, generalized anxiety disorder, alcohol dependence and bipolar disorder. The most common physical illness was visual impairment, followed by cardiovascular disease, rheumatic illnesses, pulmonary illnesses, hearing impairment, genitourinary diseases and neurological disorders. Presence of dementia was associated with increased age, single/widowed/separated status, nuclear family, economic dependence, low education, cardiovascular disorders, rheumatic disorders and neurological disorders. Depression was associated with female sex, single/widowed/separated status, staying in nuclear families, economic dependence on others and co-morbid physical illnesses, specifically cardiovascular disorders and visual impairment.Conclusions:This study presented a higher rate of dementia and old age depression. The interesting association with several sociodemographic factors as well as physical illnesses may have important implications for health planning.

Background:Little work has been done in India on the personality factors of alcoholics. These personality factors have a significant effect on treatment outcome.Aim:To study the personality characteristics, stressful life events and diagnostic utility of the Michigan Alcoholism Screening Test (MAST) and CAGE (Cutting down, Annoyance by criticism, Guilty feeling, and Eye-opener) Questionnaire in service personnel with alcohol dependence.Methods:Psychological assessment of 100 consecutive male inpatients meeting the DSM-IV criteria for alcohol dependence, and an equal number of controls matched for age, sex, occupation and regional background was carried out utilizing the MAST, CAGE Questionnaire, State-Trait Anxiety Inventory, Hamilton Rating Scale for Depression, Multiphasic Personality Questionnaire, Maudsley Personality Inventory, Toronto Alexithymia Scale, Self-esteem Inventory and Presumptive Stressful Life Events scale.Results:The MAST and CAGE were of limited value in the diagnosis of alcohol dependence. Alcoholics obtained significantly higher scores on state and trait anxiety, depression, mania scale, paranoia scale, schizophrenia scale, psychopathic deviance, neuroticism, extroversion, and the Presumptive Stressful Life Events scale. Alcohol-dependent individuals had significantly lower self-esteem compared with control subjects, and significantly more alcoholics were identified as alexithymic.Conclusion:Alcohol-dependent individuals show significantly high neuroticism, extroversion, anxiety, depression, psychopathic deviation, stressful life events and significantly low self-esteem as compared with normal control subjects. Significantly more alcoholics were found to be alexithymic compared with normal controls.