The causes of mental depression are highlighted below: 1. Frequent 'mood swings'. Such as - stubbornness , depression , sudden anxiety, etc. 2. It is very easy to get frustrated. 3. Life seems meaningless. Suffering from guilt over small matters. 4. Keep yourself away from any pleasure. It can also lead to sexual aversion. 5. Anger , sadness , arrogance are kept inside , not allowed to be expressed. . Insomnia can also lead to mental exhaustion. . Inability to make decisions. . It's easy to lose interest in something. 9. Not being able to give priority to one's own big and small desires. 10. Too much thinking about death.