Objectives: 1). To compare the economic and social impact of mental illness between those who receive early and delayed treatment, between those with early and late onset of disease, and between those with short and long durations of illness. 2) To examine the effectiveness of home visits made by community health workers in improving patients’ outcomes (by conducting a before-and-after home visit evaluation among those who receive visits). Methods: The mixed method study design was employed. First a cross-sectional community survey was conducted by sampling: 1) psychotic patients aged 18 or above residing in the catchment areas of Thammasat University Hospital and its primary care unit (PCU), namely the areas administered by Kukot and Lamsamkaew Municipalities, who had had histories of receiving psychiatric treatment at the hospital and its PCU, 2) individuals living in the areas who had been screened positive for psychiatric conditions in the earlier community survey (year 1) and 3) psychiatric individuals who were so called “hard to reach” and recruited by using a technique called chain referral method (i.e. by asking community residents to introduce patients they had seen or known in the area). Face-to-face interviews were conducted by trained interviewers with the World Mental Health - Composite International Diagnostic Interview version 3.0 (WMH-CIDI 3.0)-Thai version, eliciting sociodemographic information, education, employment, finances, DSM-IV diagnoses (including psychosis, depressive disorders and alcohol use disorders), chronic physical conditions, history of service use, health care coverage and family burden. The second study design employed was before-and-after treatment without control group. The intervention was home visit delivered by community health workers to those who had had histories of medication non-adherence or losses to follow up, and were therefore at increased risk of relapse and rehospitalization. Results: The sample comprised a total of 623 participants (respondent rate 89.1%). The majority of the sample were recruited using the chain referral method. The proportion of those with a lifetime history of psychotic symptoms was 88.9%, depressive disorders 81.4% and alcohol use disorders 19.6%. Multivariable analyses revealed that early onset of illness was significantly associated with increased risk for low educational attainment, unemployment, reduced annual earnings and metabolic syndrome. History of delayed treatment was significantly associated with increased risk for low educational attainment. Long duration of illness was significantly associated with unemployment and reduced annual earnings, whereas relatively short duration of illness was significantly associated with greater risk of metabolic syndrome. In terms of family burden, the majority of carers reported substantial or great burden related to illness such as keeping (him/her) company, giving emotional support, and helping with medication. More than half reported time spent on caregiving at 8-9 hours/week. The majority of carers also reported substantial or much embarrassment due to having a mentally ill relative. More than a third reported financial burden caused by caregiving. The majority of respondents had had received psychiatric treatment (86.4%), most of whom were in regular follow-up (57.1%), followed by those who had lost to follow-up for less than a year (20.5%) and for a year or more (14.2%). Of those who had never sought treatment (N=301), 38.2% were able to get treatment after the interview assessment. A total of 61 respondents received home visits. After a period of visits, the majority of these respondents showed improvements in almost all areas under evaluation, except employment, quality of caregiver and home environment. Conclusions: A substantial number of psychiatric patients in the community has dropped out from treatment, or never even received treatment. These patients would never have had access to regular and adequate treatment if psychiatric care was only facility-based without community involvement. Proving early treatment without delay, especially to those with early onset of disease, and continuous care, by effective interventions such as home visits, is essential. This will help reduce the long term serious impact of illness such as school dropout, unemployment, family burden, chronic physical diseases. Development and evaluation of innovative early identification and continuous care methods in the community, with the help of modern technology, is essential in reducing the accessibility and treatment gap experienced by mentally ill patients.