Today many people are suffering from mental illness in the world. Mental illnesses are health conditions involving changes in emotion, thinking or behavior and it associates with distress and functional problems in social, family activities. The aim of this paper shows how to examine about the mental illness using big data analytics. This review paper also presents a comparative analysis of different data analytics algorithms for mental healthcare. We have given a details description about five types of mental illness such as anxiety, depression, mood, bipolar, personality disorders and their effect of mental health on patient’s natures and characteristics such as Suicide and drug addiction. Artificial intelligence and machine learning are used for prediction about the mental patient such as their behavior. IoT is also used for smart devices like smart watches and innovative bands to measure the mental healthcare system.