This is a well worn question but what it is really asking is whether a domesic cat will suffer psychologically if he/she is kept indoors. You could answer the question by saying that millions of Americans keep their cats indoors. The cats seem to be fine. They quite possibly are okay psychologically but we don’t really know for sure because we can’t interview a cat or read his mind. And they are damn good at hiding their feelings.

A better way to answer the question is to apply a bit of science and for that I’ll fall back on Dr Bradshaw and what he writes in his book Cat Sense. He makes it clear that ‘domestic cats have probably become so flexible in their demands for space that they can, under the right circumstances, adapt adequately to indoor living’.
He qualifies this statement by writing, ‘cats that are destined for a life indoors should probably never be allowed outdoors, so that they can’t miss what they’ve never had’.
This tells me that cats who have sampled the outdoors might be unhappy if made to adopt to the indoors full-time. But as he says the domestic cat is flexible. He also puts to one side the cat’s genetic inheritance. Do domestic cats inherit the desire to live in a space greater than provided by an apartment?
It is probably fair to say that no domestic cat would naturally confine herself to living in a space the size of an apartment no matter how spacious but the flexibility and adaptability of the domestic cat allows her to accept the restriction of an apartment without undue stress.
The final ingredient in this equation is that indoor cats should enyoy some catification (to use Jackson’s words) of the indoors. This means an environment which entertains, stimulates and challenges to a certain extent. The reason: to avoid boredom and psychological problems and to help the cat adapt.
Refer to cat killer story , yes keep your cat in.
There really is no choice in many situations anymore. We are adding a wall that will be 100% catification on one side. We are also discussing adding a catio even a small one