The genre trappings in Karel Reisz’s Morgan  A Suitable Case for Treatment are minimal (a mentally ill young man begins to imagine himself as a gorilla, spurred on in part by a screening of King Kong (1933)) which does at least mean that all but the most determined of completists will be spared the need to suffer through it. So many comedies filmed during and set in “Swinging London” can feel head-scratchingly unfunny today, as any comedy trying to cross cultural divides so often do. The film’s self-conscious modishness would have felt dated within months, if not weeks, of its release, such was the pace of cultural change at the time and today it often feels positively neanderthal.

The eponymous suitable case for treatment is Morgan Delt (David Warner), a working-class London artist who isn’t dealing with the divorce from his upper-middle-class wife Leonie (Vanessa Redgrave) at all well. She’s had enough of his childish antics – and no-one could really blame her – and is planning to marry art gallery owner Charles Napier (Robert Stephens). The deranged Morgan lives in a fantasy world, imagining himself a gorilla and staging outlandish stunts and pranks to try to win Leonie back, including using a bomb to blow up a bed her mother is sitting on. His behaviour deteriorates to the point where he gets Wally “The Gorilla” (Arthur Mullard), a professional wrestler and friend of his Stalinist mother (Irene Handl), to help him kidnap Leonie. When she’s rescued, Morgan is imprisoned but he escapes, dons a gorilla suit and heads for her wedding…

Morgan began life as a television play, simply titled A Suitable Case for Treatment, by David Mercer, which he expanded and adapted himself into this screen version. It was originally broadcast by the BBC on 21 October 1962 as part of its Sunday-Night Play strand, with Ian Hendry and Moira Redmond in the leading roles. Sadly, it fell afoul of the Beeb’s tendency to wipe and reuse its stock of videotape and has long since been erased. Despite the expansion, the film version seems to have seriously “dumbed down” some aspects of the play and added a good deal of knockabout humour (the Mullard character for one was completely new to the film) that grates more than it entertains.

A major problem with the film version of A Suitable Case for Treatment is that although Warner was always an excellent actor, the character he’s playing here is an utter creep, his obsessive stalking of Leonie only partially disguised as 60s larkishness. He’s a bully and a potential danger to Leonie, breaking into other home, telling her, leeringly, that there’s no such thing as rape between a husband and wife, kidnaps her and ultimately gate-crashes her wedding out of sheer spite, jealousy and an inability to accept that their relationship is over. He’s a jerk, as indeed were so many of the younger protagonists in mid to late-60s British cinema. That they’ve become so revered by some – mostly men of course – through a misplaced nostalgia for a time they barely experienced is in itself depressing.

It wouldn’t have been so bad if Mercer had anything useful to say about mental illness, but Morgan’s condition is barely touched upon in any meaningful way and is largely played for laughs. He’s dangerously unwell and while his expressions of alienation and depression are seemingly just childish, they pose a real threat to Leonie and her family. We’re supposed to identify with Morgan, to empathise with his struggle but there’s no depth to the film’s study of mental illness at all and he ends up the obnoxious sort we’d go out of our ways to avoid in real life. The film also flirts with other big ideas – class, politics, the psychology of R.D. Laing (Mercer had become familiar with Laing’s work since the television play and rewrote the script accordingly) – but somehow the film manages to fumble all that too.

Tonally it’s all over the shop and Reisz – who was coming to Morgan on the heels of Saturday Night and Sunday Morning (1960) and Night Must Fall (1964) and was on the way to the likes of Isadora (1968) and The French Lieutenant’s Woman (1981) – never really seems to have got to grips with the script. It lumbers backwards and forwards between knockabout silliness and much darker material with abandon, and the occasional intrusion of fantastical material – Morgan’s hallucinations, allusions to King Kong and Tarzan – often feel out of place (it seems that they were largely absent from the small screen version).

If it’s worth seeing today, that would be entirely down to the cast. That there’s a shred of likability in Morgan – and it really is just a shred – is entirely down to Warner who manages to convey some of the anguish and sadness in the character and both he and Redgrave are game enough to bring a little dignity to roles that might have defeated lesser actors, though you are left wondering what an intelligent woman like Leonie ever saw in Morgan. Stephens is given less to do but turns the role that should have been the villain of the piece into something far more sympathetic. And at least the supporting cast is full of familiar British film faces – there’s Bernard Bresslaw as a policeman who strikes up an unlikely friendship with Morgan, Graham Crowden as a barrister and Irene Handl as Morgan’s determinedly Stalinist mother, giving by far the funniest performance in the film.

Nostalgia dictates that there’s a cult following for Morgan  A Suitable Case for Treatment but it’s a hard one to either fathom or justify. All its key ideas are sound ones but none of them really work as it’s just so hard to warm to the appalling Morgan himself. Of all of the youth oriented, “Swinging London” films from the period, it’s one that’s aged particularly badly. None of them work terribly well today except as simple nostalgia or anemoia (a nostalgia for a time before you were born), but Morgan works less well than most, mainly because we’re being asked to sympathise with such a hight resistible character. “The fact that we can laugh at Morgan does not mean that we do not sympathize with him,” Reisz once said. And that’s very true, but making him a self-absorbed and very dangerous narcissist does nothing engender any such sympathy.

An adaptation of A Suitable Case for Treatment was originally planned to be one part of an anthology, Red White and Zero, with Tony Richardson and Lindsay Anderson handling the other segments. Reisz’s adaptation of Mercer’s play was expanded to feature length, leaving Anderson to make The White Bus, Richardson to contribute Red and Blue (also starring Redgrave) with Peter Brook stepping to replace Reisz with Ride of the Valkyrie. The film was never released theatrically in this form (though The White Bus had some standalone screenings) and was largely sight unseen until a BFI blu-ray restored it to its original form in 2018.