First of all, how exactly is he acting? No Bettas, while they are prone to depression, are not normally depressed. They do this when there is something wrong. This may be the sign of just being lonely, or it may be the start of disease, or it may be constipation, or it may be that he doesn't like his environment for some reason.
Is he responding to you when he hasn't been depressed?
Is he new to you? How long have you had him? If he is new to you, the newness is probably the problem. It takes time for a Betta to build up a relationship with a human. They are culturally deprived for the first part of their lives and they think alone is what they are meant to be. It takes much work to develop the trust. Handfeeding is a trial and error (mostly error at first) way to develop the trust and probably the very best way to make a personal contact with a Betta. I agree with Butterfly that more than one person in the family needs to learn to handfeed but for the first little bit one person is probably all he can handle. Until you have established the rapport with him, he is going to be standoffish.
If on the otherhand, you have had him for a while and he has shown closeness to you and come to you before and now is not, then you have a problem of some kind. I would start with the disease issue first just in case.
Is there any change in his eating habits?
Does there appear to be any change in his swimming? More activity? Less actiivity? Shimmying when he swims (sign of constipation)?
Is there any change in his appearance? Look VERY closely, sometimes the change can be VERY small. Get a flashlight and turn off the light and shine the flashlignt on him after you have checked him in the light just to make sure he doesn't have Velvet.
Is the water quality good? What are the tests for Ammonia, Nitrate, and Nitrite readings?
What is the temperature of your tank? Do not go by the thermostat on your heater, go get a thermometer and check to make sure that your heater is working properly. It should be checked clear across the tank from the heater to make sure your heat is being distributed to all the water.
Is he goiing to the top of the tank occasionally to butt the top of his head against the surface of the water? If not this is serious as this is how they "breathe" through their Labyrinth organ.
The answers to these questions are going to mean taking time and really watching and spending time getting to know him in ways you probably haven't yet. If he is not liking his food or something in his tank, that is something you will have a chance to see when you spend time watching him as well. He will just plain avoid it.
But my true and honest opinion will run with either chance that he is getting sick or he is lonely or bored.
One simple thing you can try if you have him coming to get his food is giving him the frozen pea treatment instead of his regular food for one meal. Get One frozen pea - like the kind from the grocery store- and defrost it for 30 sec in the microwave. Don't cook it or it will just sink. Remove the skin an cut it up in tiny pieces and feed him enough to equal about half the size of his eye. (His stomach is about the size of his eye.) This is a harmless non-chemical treatment for constipation and won't hurt him even if he isn't. If this should be the problem, and for some reason Bettas are prone to constipation, it may be a quick and rather inexpensive fix for the problem. If it is not the fix, you should still probably keep them on hand if you are going to keep a Betta because I can nearly promise that even if you try very hard to keep it from happening, someday you will have a constipated little Betta.
I am so sorry not to be more helpful, but I really do need to know some of the information I asked for to make a good answer. If he shows any of the above problems or even if you have any more symptoms I haven't mentioned, PLEASE let us know. I do want to help.
Well first of all you need to know if he is truly depressed of if there is an underlying problem. Rose asked plenty of questions to figure that out.
If he truly is perfectly healthy but depressed, you need to do more than just talk to him. Be there for him. Sit by him for every free minute. Sing him every song you know. Grab your favorite book and read it to him until you lose your voice. Tell him everything that has happened in your day. Let him know that you love him and are there for him. Then maybe he will start to brighten up.
Thanx for the ideas,
I have noticed he is swimming a round the bottom of the tank most of the time. when I went in my room at the end of the day (that's where the tank is) he flared up, and stared at me, his usual sapphire blue scales turning a red/purple, like he would if you introduced him to another betta male. I immediatly stopped what I was doing, and stood by the talk talking reasurringly to him. He gradually settled down.
It can't be constipation, or a health disease, because I checked him all over before purchasing him, from my preffered aquarium shop, because of their expertice in caring for betta's (they are one of the few aquarium shops I have been to that kept their bettas in a proper tank, not a glass!!
I've had him roughly 2 months now, and he has settled in well (i think) even with our kitten, Monty testing his luck...
Luckily, when I found him within a rulers length of Orions tank, I got the spray bottle (which works well!) ;D
I feed him every day, after researching on the web, and using some books, I found out how much of what I should feed him. I'm just stumped. I clean the water regularily, and talk and croon him it seems a billion times a day. :-\
Okay, if you read in a book how much of what to feed him, what did it say? I have found some books say "give them what they will eat in 2 minutes" or "feed them frozen bloodworms" both of which are wrong. (and lead to constipation and disease)
The right Betta meal is:
Pellets (if that is his meal choice): 3 - 4 pellets twice a day (no more than that no matter what)
Bloodworms (FREEZE-DRIED) (If that is his choice): 6 - 7 worms twice a day (no more than that no matter what)
This does not mean Pellets AND Bloodworms. It means either Pellets OR Bloodworms, not both. Otherwise, you are leaving yourself wide open for a sick Betta. If this is what you have been doing please accept my apologies but so many times we run into well meaning people who think they are staving their Bettas if they don't give them a lot to eat or until they start to go away from the food. That is way too much and bad for the fish. I am just trying to make sure your Betta does not fall into that category.
I do think it is wonderful that you talk and croon to him and that you saved him from the kitten. He would surely not have appreciated her attention ;D. He sounds like he does recognize your attention and want to get to know you so half the job is done. Maybe he is just trying to tell you he wants more, in which case you are the only one to determine whether you have the time to give. Sometimes Bettas who are placed in rooms where there is not much human activity do crave more activity around them. Is there a small TV you could leave on for a few hours a day? Mine watch television while I am away and get very upset when I forget to leave it on, but again I do spoil them unmercifully. (and they are used to me being at their beck and call 24/7 pretty much). I do caution against getting them THAT spoiled
I hope some of this helps a little. I do so hate to hear of a distressed Betta. I feel they are all part of a family of friends of my little guys and they need to be happy. Let us know how he is progressing, please.