user8157: I read the following on the internet:

The reason that Secular Buddhists (who do not admit the conventional
existence of rebirth) do not commit suicide is because they believe in
the true existence of the self in this very life.

Are there any Buddhist scriptures or teachings that say belief in true existence of the self prevents suicide?

user13375: It appears suicide is caused -- not by belief in true existence of the self (or "the view of true self") -- but by craving for the true non-existence of the self, as follows:

How, bhikkhus, do some overreach? Now some are troubled, ashamed, and
disgusted by this very same being and they rejoice in (the idea of)
non-being, asserting: ‘In as much as this self, good sirs, when the
body perishes at death, is annihilated and destroyed and does not
exist after death—this is peaceful, this is excellent, this is
reality!’ Thus, bhikkhus, do some overreach.
Iti 49

Suicide arises from vibhava tanha. Vibhava is also a self-view; just as the doctrine of annihilationism is a self-view. It is craving for the annihilation of the true self which can cause suicide.


Annihilationism (Ucchedavāda): Views 51–57

"There are, bhikkhus, some recluses and brahmins who are annihilationists and who on seven grounds proclaim the annihilation,
destruction, and extermination of an existent being. And owing to
what, with reference to what, do these honorable recluses and brahmins
proclaim their views?

"Herein, bhikkhus, a certain recluse or a brahmin asserts the following doctrine and view: 'The self, good sir, has material form;
it is composed of the four primary elements and originates from father
and mother. Since this self, good sir, is annihilated and destroyed
with the breakup of the body and does not exist after death, at this
point the self is completely annihilated.' In this way some proclaim
the annihilation, destruction, and extermination of an existent being.


DN 1

The original answer that prompted this OP has been edited to make this clear.

8157: <p>I read the following on the internet:</p>
<blockquote>
<p>The reason that Secular Buddhists (who do not admit the conventional
existence of rebirth) do not commit suicide is because they believe in
the true existence of the self in this very life.</p>
</blockquote>
<p>Are there any Buddhist scriptures or teachings that say belief in true existence of the self prevents suicide?</p>
 13375: <p>It appears suicide is caused -- not by belief in true existence of the self (or &quot;the view of true self&quot;) -- but by craving for the true non-existence of the self, as follows:</p>
<blockquote>
<p>How, bhikkhus, do some overreach? Now <strong>some are troubled, ashamed, and
disgusted</strong> by this very same being and they <strong>rejoice in (the idea of)
non-being</strong>, asserting: ‘In as much as this self, good sirs, when the
body perishes at death, <strong>is annihilated and destroyed and does not
exist after death</strong>—this is peaceful, this is excellent, this is
reality!’ Thus, bhikkhus, do some overreach.</p>
<p><a href="https://www.accesstoinsight.org/tipitaka/kn/iti/iti.2.042-049x.irel.html#iti-049" rel="nofollow noreferrer">Iti 49</a></p>
</blockquote>
<p>Suicide arises from vibhava tanha. Vibhava is also a self-view; just as the doctrine of annihilationism is a self-view. It is craving for the annihilation of the true self which can cause suicide.</p>
<blockquote>
<ol start="4">
<li><p>Annihilationism (Ucchedavāda): Views 51–57</p>
</li>
<li><p>&quot;There are, bhikkhus, some recluses and brahmins who are annihilationists and who on seven grounds proclaim the <strong>annihilation,
destruction, and extermination of an existent being</strong>. And owing to
what, with reference to what, do these honorable recluses and brahmins
proclaim their views?</p>
</li>
<li><p>&quot;Herein, bhikkhus, a certain recluse or a brahmin asserts the following doctrine and view: 'The self, good sir, has material form;
it is composed of the four primary elements and originates from father
and mother. Since <strong>this self, good sir, is annihilated and destroyed
with the breakup of the body and does not exist after death, at this
point <strong>the self</strong> is completely annihilated.'</strong> In this way some proclaim
the <strong>annihilation, destruction, and extermination of an existent being</strong>.</p>
</li>
</ol>
<p><a href="https://www.accesstoinsight.org/tipitaka/dn/dn.01.0.bodh.html" rel="nofollow noreferrer">DN 1</a></p>
</blockquote>
<p>The <a href="https://buddhism.stackexchange.com/a/44855/13375">original answer</a> that prompted this OP has been edited to make this clear.</p>
