Possible to cast Mind Spike without breaking concentration? [duplicate]

Question

Mind Spike is cast with one action but has concentration up to an hour. Unless I'm mistaken, the actual casting process of the spell does not take concentration, due to it not being longer than a single action. Ending concentration is a non-action that can be taken at any time. Would it be possible for a player to cast it but choose to not concentrate on it after the initial damage, thus not breaking concentration on another spell?

The main reason I'm wondering this is because Mind Spike is the only weaponized Divination spell, and actually scales with higher slot levels. I could see this being used to get the most out of a Divination Wizard's Expert Divination class ability.

It makes sense that this would be possible to me, but I'd like to know a more concrete ruling.

Answer 1

PHB page 203 says

The following factors can break concentration:
* Casting another spell that requires concentration.

So by RAW your concentration on the first spell ends and there is no option to not concentrate on the new spell in order to keep concentration on the old one.

Answer 2

You lose concentration on a spell if you cast another spell that requires concentration.

Basic Rules > Spellcasting > Casting a Spell > Duration > Concentration

Casting another spell that requires concentration breaks the existing concentration of any other spell, even if you stop concentrating on it immediately- just the act of casting the other concentration spell is enough to do so, regardless of how long you actually concentrate.

This is further reinforced by a statement from Jeremy Crawford, lead rules designer of D&D5e:

@JeremyECrawford If you have a concentration spell and cast an offensive con spell that failed due st, do you loose your initial spell?

@Lexar131, 6 Jun 2017

If you're concentrating on a spell, your concentration on it ends the moment you start casting another concentration spell. #DnD

@JeremyECrawford, 6 Jun 2017