Manic-depressive patients, in their manic moments, the most improbable things in [that] state: plunder their bank account, weeks staying in a five star hotel, numerous cars on buying one day. At that stage they are not mentally competent, that is obvious. But come in moments of depression they back their exhaustion to the baseline, and they are indeed competent. Then they can say, for example: "I live for thirty years crazy highs and lows, I've tried everything to break that infernal cycle, including psychiatric hospitalization, but now I'm back on the baseline, and I know I have a few weeks left'm back for a dip in the depth or a jump in height. " These are people who are eligible for euthanasia.
Despite the slightly garbled translation, it's quite clear that Distelmans is saying this: In the manic stage, bipolar patients are not mentally competent. But when the manic stage ends and they are feeling deeply depressed but have not gone into a new low-high cycle, they are fully mentally competent and are eligible to make a rational choice for euthanasia, because they fear the resumption of their manic-depressive cycles.
This is a classic case of choice devours itself, because it dumbs down the concept of rational and mentally competent choice in an attempt to garner more death outcomes in cases where those advocating policy think it would be good for the people in question to die. If the euthanasia bureaucrats think you are better off dead, then a stage of your mental illness in which you think you are better off dead is conveniently redefined as "rationality" rather than mental illness rendering you incompetent for making important decisions (you know, like whether to live or die). If the notion of "rational suicide" wasn't a joke to begin with (and it kind of was, wasn't it?) this makes it obviously a joke.
Which tells us yet again that this is not about free choice and never was. It's about making the people dead who, the Controllers believe, ought to be dead.