Research has shown that acupuncture treatment may specifically benefit anxiety disorders and symptoms of anxiety by:
• Acting on areas of the brain known to reduce sensitivity to pain and stress, as well as promoting relaxation and deactivating the ‘analytical’ brain, which is responsible for anxiety and worry 
• Regulating levels of neurotransmitters (or their modulators) and hormones such as serotonin, noradrenaline,
dopamine, GABA, neuropeptide Y and ACTH; hence altering the brain’s mood chemistry to help to combat negative affective states 
• Stimulating production of endogenous opioids that affect the autonomic nervous system . Stress activates the sympathetic nervous system, while acupuncture can activate the opposing parasympathetic nervous system, which initiates the relaxation response.
• Reversing pathological changes in levels of inflammatory cytokines that are associated with anxiety 
• Reversing stress-induced changes in behaviour and biochemistry 
Acupuncture can be safely combined with conventional treatments such as medication or psycho-educational therapy, possibly enhancing their beneficial effects (Courbasson 2007) and reducing unwanted side-effects 
From the British Acupuncture Council’s research factsheet Hui KK et al. Acupuncture, the limbic system, and the anticorrelated networks of the brain. Auton Neurosci. 2010 Oct 28;157(1-2):81-90  Lee B et al. Effects of acupuncture on chronic corticosterone-induced depression-like behavior and expression of neuropeptide Y in the rats. Neuroscience Letters 2009; 453: 151-6
Samuels N et al. Acupuncture for psychiatric illness: a literature review. Behav Med 2008; 34: 55-64
Zhou Q et al. The effect of electro-acupuncture on the imbalance between monoamine neurotransmitters and GABA in the CNS of rats with chronic emotional stress-induced anxiety. Int J Clin Acupunct 2008 ;17: 79-84.
Yuan Q. Li J.-N. Liu B. Wu Z.-F. Jin R. Effect of Jin-3-needling therapy on plasma corticosteroid, adrenocorticotropic hormone and platelet 5-HT levels in patients with generalized anxiety disorder. Chinese Journal of Integrative Medicine.2007; 13 (4): 264-268. Arranz L et al. Effect of acupuncture treatment on the immune function impairment found in anxious women. American Journal of Chinese Medicine. 2007;35(1):35-51  Kim H et al. The effects of acupuncture stimulation at PC6 (Neiguan) on chronic mild stress-induced biochemical and behavioral responses. Neuroscience Letters. 2009; 460 (1) (pp 56-60)  Courbasson CM. et al .Acupuncture treatment for women with concurrent substance use and anxiety/depression: an effective alternative therapy? Family & Community Health.2007;30(2):112-2
Acupuncture for stress and anxiety