diff --git a/sql/updates/world/master/2026_01_11_02_world.sql b/sql/updates/world/master/2026_01_11_02_world.sql
new file mode 100644
index 00000000000..6f0c56c6a54
--- /dev/null
+++ b/sql/updates/world/master/2026_01_11_02_world.sql
@@ -0,0 +1,7 @@
+DELETE FROM `spell_script_names` WHERE `ScriptName`='spell_pri_mental_decay';
+INSERT INTO `spell_script_names` (`spell_id`, `ScriptName`) VALUES
+(375994,'spell_pri_mental_decay');
+
+DELETE FROM `spell_proc` WHERE `SpellId` IN (375994);
+INSERT INTO `spell_proc` (`SpellId`,`SchoolMask`,`SpellFamilyName`,`SpellFamilyMask0`,`SpellFamilyMask1`,`SpellFamilyMask2`,`SpellFamilyMask3`,`ProcFlags`,`ProcFlags2`,`SpellTypeMask`,`SpellPhaseMask`,`HitMask`,`AttributesMask`,`DisableEffectsMask`,`ProcsPerMinute`,`Chance`,`Cooldown`,`Charges`) VALUES
+(375994,0x00,6,0x00000000,0x00000000,0x00000040,0x00000000,0x0,0x0,0x0,0x2,0x0,0x0,0x0,0,0,0,0); -- Mental Decay
diff --git a/src/server/scripts/Spells/spell_priest.cpp b/src/server/scripts/Spells/spell_priest.cpp
index a0b9460e5d1..7315203f4dd 100644
--- a/src/server/scripts/Spells/spell_priest.cpp
+++ b/src/server/scripts/Spells/spell_priest.cpp
@@ -2641,6 +2641,42 @@ class spell_pri_lights_wrath : public SpellScript
     }
 };
 
+// 375994 - Mental Decay
+class spell_pri_mental_decay : public AuraScript
+{
+    bool Validate(SpellInfo const* /*spellInfo*/) override
+    {
+        return ValidateSpellInfo({ SPELL_PRIEST_SHADOW_WORD_PAIN, SPELL_PRIEST_VAMPIRIC_TOUCH });
+    }
+
+    static void HandleEffectProc(AuraScript const&, AuraEffect const* aurEff, ProcEventInfo const& eventInfo)
+    {
+        Unit* caster = eventInfo.GetActor();
+        if (!caster)
+            return;
+
+        Unit* target = eventInfo.GetActionTarget();
+        int32 durationExtend = aurEff->GetAmount() * IN_MILLISECONDS;
+
+        if (Aura* shadowWordPain = target->GetOwnedAura(SPELL_PRIEST_SHADOW_WORD_PAIN, caster->GetGUID()))
+        {
+            shadowWordPain->SetMaxDuration(shadowWordPain->GetDuration() + durationExtend);
+            shadowWordPain->SetDuration(shadowWordPain->GetDuration() + durationExtend);
+        }
+
+        if (Aura* vampiricTouch = target->GetOwnedAura(SPELL_PRIEST_VAMPIRIC_TOUCH, caster->GetGUID()))
+        {
+            vampiricTouch->SetMaxDuration(vampiricTouch->GetDuration() + durationExtend);
+            vampiricTouch->SetDuration(vampiricTouch->GetDuration() + durationExtend);
+        }
+    }
+
+    void Register() override
+    {
+        OnEffectProc += AuraEffectProcFn(spell_pri_mental_decay::HandleEffectProc, EFFECT_0, SPELL_AURA_DUMMY);
+    }
+};
+
 // 205369 - Mind Bomb
 class spell_pri_mind_bomb : public AuraScript
 {
@@ -5125,6 +5161,7 @@ void AddSC_priest_spell_scripts()
     RegisterSpellScript(spell_pri_leap_of_faith_effect_trigger);
     RegisterSpellScript(spell_pri_levitate);
     RegisterSpellScript(spell_pri_lights_wrath);
+    RegisterSpellScript(spell_pri_mental_decay);
     RegisterSpellScript(spell_pri_mind_bomb);
     RegisterSpellScript(spell_pri_mind_devourer);
     RegisterSpellAndAuraScriptPair(spell_pri_mind_devourer_buff, spell_pri_mind_devourer_buff_aura);