According to WHO (World Health Organization) mental illness or brain health presented withering rates of prevalence, morbidity, mortality, and disability. Suffering from a serious mental condition reduces the overall average life expectancy. Other than mortality, in most of the Western countries, mental diseases are the leading cause of disability and also responsible for 30-40% of chronic sick leave, which costs around 4% of gross domestic product. Pharmacological treatment options for all types of mental illness are scarce and show limited efficacy. Several clinical studies indicated the significant limitations of current pharmacological interventions in terms of recovery and remission. In a Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) study, approx 74% of patients with chronic schizophrenia experienced trouble of treatment adherence within 1.5 years. In addition, in the STAR*D (Sequenced Treatment Alternatives to Relieve Depression) research study only thirty one percent of patients with MDD (major depressive disorder) were in remission even after being managed with the use of a selective serotonin reuptake (SSR) inhibitor.
Several factors generally contribute to the clinical associations and the heterogeneity/complexity of mental diseases. Patients suffering from a mental disorder showed several symptoms related with thinking, behavior, social interaction and/or feelings. According to the ICD- International Statistical Classification of Diseases and Related Health Problems or DSM-Diagnostic and Statistical Manual of Mental Disorders, mental disorders are classified with a diverse list of symptoms to alleviate the diagnose. Patients diagnosed with a similar or unique psychiatric illness showed a great heterogeneity in their clinical settings presentation. In addition, various mental illnesses present common symptoms which can often make the diagnosis much difficult.
Psychiatric diseases, on the other hand, present high comorbidity. Approximately 90% of patients with anxiety also experience symptoms of depression, and vice versa. Among schizophrenic patients with unique symptoms, psychiatric comorbidities are common. In the approx 50% of patients, suffering from depression,almost half have a lifetime diagnosis of co-morbid substance use disorders. When two or more psychiatric diseases present simultaneously, these are associated with worse response to the pharmacological treatment, greater severity, and have a greater risk of suicide tendencies compared to one condition alone.
Despite these facts, advent of new omics technologies and progress in human brain research, offers the possibilities and opportunity to change mental health outcome and treatments in a near future. In this current scenario, the identification and characterization of novel biomarkers has become a promising tool for predicting clinical outcome, guiding diagnosis, and improving the pathophysiological understanding of mental disorders. Recent studies had provided the support and encouraging to improve the current state of biomarkers in neuropsychiatry. Research groups are aiming to achieve some goals and solving future challenges which are needed to develop valid, reliable and broadly-usable common biomarkers for psychiatric disorders. The role of ‘omics’ is very interesting and it should be explored more in greater detail.