Though development actors have pledged to focus their work on the most vulnerable in the society, many of their interventions have ignored the target group.
The World Health Organisation (WHO), which made this known on Wednesday, said people with mental and physiological disabilities are among the most marginalised group in developing countries.
The WHO report on Mental Health and Development - Targeting People with Mental Health Conditions as a Vulnerable Group, was copied to the Ghana News Agency in Accra.
According to the report, the majority of development and poverty alleviation programmes did not reach persons with mental or psychological disabilities. For example, between 75 per cent and 85 per cent of patients did not have access to any form of mental treatment.
Mental and psychological disabilities are associated with rates of unemployment as high as 90 per cent. Furthermore people are not provided with educational and vocational opportunities to meet their full potential.
"A greater attention from the development community is needed to reverse this situation", says Dr Ala Alwan, Assistant Director-General in charge of Non- Communicable Diseases and Mental Health at WHO.
"The lack of visibility, voice and power of people with mental and psychological disabilities means that an extra effort needs to be made to reach out to and involve them more directly in development programmes.
The challenge is enormous. An estimated one in four people globally will experience a mental health condition in their lifetime. Mental health conditions are responsible for a great deal of mortality and disability, accounting for 8.8 per cent and 16.6 per cent of the total burden of disease due to health conditions in low and middle -income countries, the report said.
"Depression will be the second highest cause of disease burden in middle-income countries and the third highest in low-income countries by 2030, said the report which was originally launched in New York in the United States.
The report called for development actors to address the needs of people with mental and psychological disabilities in development work by recognising the vulnerability of the group and include them in all development initiatives and scaling up services for mental health in primary care, including people in income generating programmes.
It recommended the essence in involving the people in the design of development programmes and projects, incorporating human right protection in national policies and law and including children and adolescents with mental and psychological disabilities in education programmes as well as improving their social services.
The report said WHO is working jointly with the UN Department of Economic and Social affairs (UNDESA) to integrate mental health into the development agenda and programmes at the national level.
"We need to break down the barriers that continue to exclude persons with mental or psychological disabilities", said Mr Sha zukang, Under Secretary-General of UNDESA.
"In order for them to have access to better opportunities and to benefit from the fruits of development, they must also be involved in the design of policies and programmes related to development."
The WHO report stressed that by investing in people with mental health conditions, development outcomes could be improved.
Mental health priority conditions include depression, psychosis, suicide, epilepsy, and dementia, conditions due to the use of alcohol and drugs and mental health conditions in children.