well, I was about to say that it depends...
But as we're on the Buddhist forum, then I think, yes it does, in relation to your Kamma.....
If you think about complaining about something...
"Drn it! I hate these shorts! They make me look like a potato-head!" isn't so bad... and we can check that thought before we say it... saved by the bell!!
But if we're thinking along the lines of cursing someone specific, or being unkind, mental states also accrue Kammic consequences... That's why Right View, or right Understanding is the primary First Virtue on the Eightfold Path. It's about harnessing our Mind-patterns and training them to be...
good dogs, instead of wayward puppies chewing their way through the house....!
We may not always be successful...(there goes the remote!) but catching them (the thoughts) young, before they grow too big (become spoken) is by far the best way to go...!
And thought Kamma is obviously not as bad as spoken kamma....
Negative Thought kamma = slap on the wrist...
Negative Verbal Kamma = slap upside de head...
Negative Action Kamma = sparked out with a southpaw uppercut...!
It has to be remembered that you have to also be Mindful of the Intention of the thought...
The worse the Intention in the thought, the worse the kamma...
For example (and obviously, it doesn't apply here...)
If someone is deeply angry, and thinks: "I am going to give that dirty rotten SOB a piece of my mind...
That's better than -
"You wait until I have my hands on that dirty rotten SOB - I'm gonna give him such a beating...."
Is better than -
"He'd better keep out of my way. If I see him again, I'm gonna kill him, no sh1-t...."
It's an extreme example, but you see how the Intention has got progressively worse....
The provocation might be identical in all three scenarios... so the 'understanding' of what has happened, may not have changed...
But the Intention has...
Does any of this make sense....?