Dhikr is a Means to Happiness
The word "Allah" is a code. The utterance of this word creates a wavelength that will bring the lights of mercy, virtue and benedictions from Allah to your heart according to the qualities of your heart. The lights of Allah will descend from Allah, reach your chest and have an effect on you.
If you are ever in trouble, you have the most effective weapon in this universe: dhikr (repetition the name of Allah). Take ablution, sit on the prayer rug, take your rosary beads in your hand, recite the basmala, and then start dhikr inwardly saying "Allah, Allah, Allah". Five minutes is enough for this. You will see that all your troubles have been taken away by Allah.
Then Allah has a prescription. Use that prescription instead of medicines. Dhikr is such a weapon of Allah that you cannot fulfil the vow of purification of the soul that you have made to Allah with any other worship.
Allah has made it obligatory to do dhikr once in a while, much dhikr and continuous dhikr. Dhikr is the indispensable condition of the Holy Qur'an.
Dhikr once in a while
Al-Muzzammil-8: And remember (repeat) the Name of your Lord and return Him by detaching yourself from everything.
Much Dhikr
Continuous Zikr
AHZÂB - 41 O you who believe (who are Amenû, who wish their spirits to reach Allah while they are living)! Repeat the name of Allah a lot (more than half of the day).
NİSÂ - 103 And when you have completed the prayer, repeat the name of Allah standing, sitting, or lying (down) on your sides (with a continuous repetition), but when you are in safety, then perform the ritual prayer, as it should be performed; surely the prayer is enjoined on the believers at fixed hours as an obligation.