Nicola Coughlan made her name in school uniform in Derry Girls and she's back in school in the first episode of C4's new comedy Big Mood. Only this time she is there as an alumnus, a not-as-successful-as-she-claims playwright giving a motivational talk to the next generation.

Big Mood, of course, is a comedy so the first rule of sitcom is that a public speaking engagement is not going to go smoothly. Needless to say the speech leaves the audience a bit bemused. But then it's not been a good day for Maggie (Coughlan). Part of the, erm, motivation for going back to the school was that she fancied once of the teachers and that doesn't go quite to plan either.

This scene-setting opener sets out the stall for a comedy that also has its serious side. In the olden days we'd have said that Maggie is a bit chaotic. Nowadays she is, of course, bipolar (what, not ADHD?) and even just doing the normal things in life is a challenge.

Fortunately she is supported by her bessie friend Eddie (Lydia West from It's A Sin) and later in the run we meet her therapist played by Sally Phillips. Inevitably there will be comparisons with the Aisling Bea comedy This Way Up, which also dealt with mental health, though maybe not with such broad strokes.

Big Mood, created and written by Camilla Whitehall, is certainly worth watching. Channel 4 has been getting some stick recently for the quality of its programming but this is an enjoyable sitcom deftly balancing laugh-out-loud moments and serious issues. Coughlan alone makes it must-see TV. She is a little on the comedy cartoonish side in the first episode but stick around to see how her character evolves. Big Mood certainly left me in a good mood.

Big Mood, Thursdays, 10pm, C4.

Picture: C4