ずにはいられない

1. 1Cannot help doing something; a natural reaction such as crying happens involuntarily in response to a situation.Ex. 1
2. 2Cannot suppress an emotional reaction, such as anger, toward someone's behavior or a situation.Ex. 2

The pattern describes an urge or reaction that cannot be held back and is used in both speech and writing. Because of the classical negative ず, it sounds slightly more formal than ないではいられない, which has the same meaning. The triggering situation is often stated first with と or には, as in 見ると or 態度には.

• ないではいられないN2「ないではいられない」has the same meaning and is generally interchangeable with 「ずにはいられない」, but with a softer tone and less of a written-language flavor. It attaches directly to the ない-form, and する becomes 「しないではいられない」.
• ないではおかない / ずにはおかないN1「ずにはおかない」expresses the determination that something 'must' be done, or that something will inevitably arouse a certain feeling in others (often attaching to the causative form); it is fairly formal and does not express your own inability to hold back. Only its variant 「ずにはおかれない」 is close in meaning to this pattern.
• 〜ないわけにはいかないN1「ないわけにはいかない」means you 'cannot help but do' something because of social obligations, your position, or circumstances, whereas 「ずにはいられない」means an emotion or external stimulus makes you unable to hold back; the two are not interchangeable. The former attaches to the ない-form without dropping ない.
• てたまらないN2「てたまらない」describes feelings or physical sensations so strong that something is 'unbearably' so, and it can attach to adjectives, the て-form of verbs, and 「たくて」; 「ずにはいられない」attaches only to verbs and describes being unable to hold back from an action. The two are generally not interchangeable.
• てならないN2「てならない」expresses feelings, sensations, or thoughts welling up so strongly that they are hard to suppress, describing a mental state rather than an action. It can attach to verbs and adjectives and is mostly used in written language, so it should not be directly swapped with 「ずにはいられない」.
• てしょうがないN3「てしょうがない」expresses feelings or sensations that are extremely strong; it can attach to verbs and adjectives and leans colloquial, whereas 「ずにはいられない」attaches only to verbs, means being unable to hold back from an action, and is neutral in register. The two are generally not interchangeable.

ないではいられない has the same meaning and sounds more colloquial. ないではおかない / ずにはおかない means something will inevitably cause a result or that someone is determined to do something, 〜ないわけにはいかない expresses obligation from circumstances, and てたまらない, てならない and てしょうがない describe an intense feeling or state rather than an action one cannot hold back.