The Clinical Depression Concept Album Show is split into two halves. The first deals with David's depression, and the second, his recovery. In between songs, he gives more detail on his story and provides us with eloquent insights on depression and some gags. He is accompanied by two talented musicians – Dave Dhonau on cello and bass guitar and Amy Nicholson on cello, glockenspiel and vocals. The set, which is designed by Nicholson, is appropriately gloomy. The space is dark, dank and foggy, and the piano takes centre stage, beside a small table with a lamp, a bottle of whisky and a knife.

David explains that we begin "at the worst possible time" and launches straight into the first song he wrote after coming out of hospital and is back at home with his parents. Titled Crawley, it is based on his suicide note and is the slowest and saddest song of the night, though not without the occasional injection of humour (going to Sainsbury's to buy a knife and some whisky, and realising his shopping looks crazy). Significantly, it is the only song that he plays with no accompaniment from the other musicians.

Next is Scrabble for Beginners, which is accompanied by Dave on cello and recounts a story whereby he is playing Scrabble with his mum. They're not playing competitively though, on account of David barely being able to count anymore and the "cognitive fog" of depression – the slow and plodding pace of the music brilliantly mirroring David's state of mind. Their game is interrupted, however, when David receives a call from T-Mobile, who he gets rid of by saying that he is clinically depressed. At this, both David and his mum collapse into laughter and he tells us that this extraordinary moment of release and burst of hilarity is the highlight of his day. This song, incidentally, was my highlight of the show. It perfectly captured the heightened, hysterical emotions simmering beneath the surface.

Killing Spree and Tonight the Stars follow. The former marks a change of pace from the previous slower songs and is an entertaining, manic and jerky number that expresses David's desire to kill all of his family (and is the only song that David admits is not entirely truthful). It is about his perception of reality "going to pot" as a result of all the drugs he was on and not being able to tell if his cat is "Satan or not". The latter marks a turning point in David's psyche, and is a powerful, dreamy song where he realises for the first time that he doesn't want to die.

Before we head into the "recovery" portion of the evening, David chats candidly to the audience about depression and gets us to physically loosen up about it by stretching. This "chat" was, I think, successful in closing the gap between the audience and the performers and David took the opportunity to properly introduce Dave and Amy, who become more involved in the second half – reflecting David's re-integration with people as his recovery continues.

Day at a Time reflects on David's coping mechanisms and includes some heart-rending lyrics, and then there is Sweet Heart – a sweet love song with Amy contributing ethereal vocals, dedicated to his friend Sally, who first taught him some chords on the piano. Prior to this song David discussed Winston Churchill famously calling depression "Black Dog", leading Amy to wear a fascinator featuring a black dog during the song, while Dave wore a heart shaped one. This seemed a bit unnecessary and a tad too kooky for my liking – something I felt more than once during the show. There were a few moments that just seemed a bit odd and that needn't be there, such as the characterisation of Dave as an awkward mute. I also found David's style of joke-telling to be somewhat stilted, and almost as if he was imitating some perceived style of speaking associated with stand-up comics.

A perhaps misguided sing-along session with the audience permeated the next song – an ode to his piano, Ernest. It was more cheery and up-tempo than any of the others and, while I enjoyed the song, I didn't much enjoy the singing along. The final song continues the more optimistic theme. It tells the story of David's holiday to Thailand, a year after the Crawley episode. It's hopeful and lovely, and the cello playing in particular was beautiful. As the song continues, the set gradually gets brighter and the fog that clouded the stage at the beginning of the show dissipates completely. There is a wonderful cyclical element to this piece, where he says that he left a note in a tree, on which he wrote, among other things, that "it's good to be alive". Dave and Amy continue to play their cellos while David finishes his glass of whisky, turns off the lamps, goes to a tree to the left of the stage, and places a note there.

Although I found that not everything was entirely successful – the unwarranted kookiness and a somewhat stilted comic delivery in particular – these didn't detract too much from a very good show. I mostly really enjoyed the songs (even if I was forced to sing). The music was affecting and often beautiful, and this is an immensely brave and positive piece of theatre – depression should be discussed in a candid and open way and I think David Parkin has found an insightful, original and poetic way of doing this.

Good Friday, at Battersea Arts CentreEmma Burch reviews Good Friday at the Battersea Arts Centre.3