A mental disorder or mental illness is a psychological or behavioral pattern generally associated with subjective distress or disability that occurs in an individual, and which are not a part of normal development or culture. The recognition and understanding of mental health conditions has changed over time and across cultures, and there are still variations in the definition, assessment, and classification of mental disorders, although standard guideline criteria are widely accepted.
A few mental disorders are diagnosed based on the harm to others, regardless of the subject's perception of distress. Over a third of people in most countries report meeting criteria for the major categories at some point in their lives.
The causes are often explained in terms of a diathesis-stress model or biopsychosocial model. In biological psychiatry, mental disorders are conceptualized as disorders of brain circuits likely caused by developmental processes shaped by a complex interplay of genetics and experience. We can used Hearing aids for some having disability in ears.
Diagnosis
Many mental health professionals, particularly psychiatrists, seek to diagnose individuals by ascertaining their particular mental disorder. Some professionals, for example some clinical psychologists, may avoid diagnosis in favor of other assessment methods such as formulation of a client's difficulties and circumstances.The majority of mental health problems are actually assessed and treated by family physicians during consultations, who may refer on for more specialist diagnosis in acute or chronic cases. Routine diagnostic practice in mental health services typically involves an interview (which may be referred to as a mental status examination), where judgments are made of the interviewee's appearance and behavior, self-reported symptoms, mental health history, and current life circumstances. The views of relatives or other third parties may be taken into account. A physical examination to check for ill health or the effects of medications or other drugs may be conducted. Psychological testing is sometimes used via paper-and-pen or computerized questionnaires, which may include algorithms based on ticking off standardized diagnostic criteria, and in rare specialist cases neuroimaging tests may be requested, but these methods are more commonly found in research studies than routine clinical practice.Time and budgetary constraints often limit practicing psychiatrists from conducting more thorough diagnostic evaluations.It has been found that most clinicians evaluate patients using an unstructured, open-ended approach, with limited training in evidence-based assessment methods, and that inaccurate diagnosis may be common in routine practice Mental illness involving hallucinations or delusions (especially schizophrenia) are prone to misdiagnosis in developing countries due to the presence of psychotic symptoms instigated by nutritional deficiencies. Co morbidity is very common in psychiatric diagnoses, i.e. the same person given a diagnosis in more than one category of disorder.