One in eight people world wide live with some kind of mental disorder which results in significant disturbances in their thinking and emotional behaviour. While effective prevention and treatment options exist, early detection and intervention are essential for improving therapy outcomes and reducing the long-term impact of mental health conditions. Speech technology can be employed, effectively, to not only assess and monitor mental health conditions but also can contribute to the early detection of mental health. By analyzing speech patterns, including changes in speech rate, pitch, or other vocal features, algorithms can identify potential markers of conditions like depression, anxiety, or even neurodegenerative disorders such as Alzheimer’s disease, dementia. Additionally, speech technology can provide insights into a person’s emotional state, stress levels, facilitating proactive healthcare measures. In this paper, we present an overview of the speech processing technology- based research from the perspective of application to mental healthcare.